Southeast Asian J Trop Med Public Health, 1981 Dec, 12(4), 574 - 80 A survey of scrub and murine typhus in the Ancol section of Jakarta, Indonesia; Dennis DT et al.; Rickettsia tsutsugamushi was isolated from L . (L.) arenicola chiggers and three species of rats in an area of scrub and sedge along the Bay of Jakarta . This is the only finding in Indonesia of a cycle of the agent of scrub typhus associated with L . (L.) arenicola . A serologic survey of nearly 300 persons living in two kampungs near the site at which rickettsiae were recovered revealed one individual with antibodies to R . tsutsugamushi . Murine typhus, with a seropositivity rate of 6.5%, may be endemic at low levels. Minerva Med, 1981 Sep 1, 72(31), 2085 - 96 {Characteristics of the rash in Mediterranean boutonneuse fever}; Scaffidi L et al.; The typical papulomacular picture of boutonneuse fever is described . A series of atypical exanthemas is presented: simply erythemato-macular and typhus-like, nodular, vesicular . Skin biopsies showing the endothelial, thrombotic and parietal aspects of periadventitial infiltration (this being sometimes moderately and extensively pericapillary) are also presented . The reason for the absence of extensive thrombisation in extensive, marked rickettsiotic endothelitis are discussed, and stress is laid to the hitherto little-discussed, but significant involvement of dermal collagen. J Clin Microbiol, 1981 Sep, 14(3), 333 - 41 Isolation of species-specific protein antigens of Rickettsia typhi and Rickettsia prowazekii for immunodiagnosis and immunoprophylaxis; Dasch GA; A simple procedure for the selective isolation of the protective species-specific protein antigens (SPAs) of Rickettsia typhi and Rickettsia prowazekii was developed to permit use of the SPAs in the immunodiagnosis and immunoprophylaxis of typhus infections . Although the SPAs were readily extracted from lysozyme- or detergent-treated rickettsiae, as measured by rocket immunoelectrophoresis, other polypeptides were also present, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . In contrast, both water and seven buffers, each at a 10 mM concentration and pH 7.6, were nearly equally effective in the selective release of the SPAs from whole cells by extraction for 30 min at 45 degrees C . High-ionic-strength buffers and MgCl2 abolished this SPA release, thus suggesting that divalent cations were important in the binding of the SPAs to the cell envelope . The efficacy of the dilute buffer extraction procedure for isolation of large amounts of SPAs was tested by further characterization of the supernatants obtained by centrifugation (200,000 x g) of two successive tris-(hydroxymethyl)aminomethane-hydrochloride buffer (Tris) extracts . With this procedure, between 10 and 15 mg of SPA was obtained from 100 mg of purified rickettsiae . Although low-molecular-weight ribonucleic acid fragments were released into the Tris extracts in significant amounts, only the SPAs were detected, in significant quantities, as measured by polyacrylamide gel electrophoresis and rocket immunoelectrophoresis . The Tris extracts contained the same major and minor SPA polypeptides as those observed previously in SPA preparations obtained by extensive diethylaminoethyl-cellulose column chromatography, but the Tris SPAs were more satisfactory antigens in an enzyme-linked immunosorbent assay. Am J Trop Med Hyg, 1981 Jul, 30(4), 849 - 54 Scrub typhus in the Eastern Solomon Islands and Northern Vanuatu (New Hebrides); Miles JA et al.; Rickettsia tsutsugmushi has been isolated from Rattus rattus from Vanua Lava island in Northern Vanuatu (New Hebrides) and from R . exulans and Leptotrombidium akamushi on Ndende island in the Eastern Solomon Islands . The well-known vector mite L . deliense was found on Mota Lava and Vanua Lava in Vanuatu, but no isolation was made from pools of this mite . Serology confirms that R . tsutsugamushi infects humans in the Banks group of islands in Northern Vanuatu and that infection is much more widespread in the Solomon Islands than the limited isolations indicate. JAMA, 1981 Jun 12, 245(22), 2318 - 23 Epidemic typhus in the United States associated with flying squirrels; Duma RJ et al.; Between July 1977 and January 1980, seven cases of sporadic, nonepidemic "epidemic" typhus (Rickettsia prowazekii) were discovered in Virginia, West Virginia, and North Carolina . The reservoir seemed to be the southern flying squirrel (Glaucomys volans), an animal indigenous to the eastern United States; however, the vector or mode of acquisition was not evident . Diagnosis was established principally through complement fixation, indirect immunofluorescence, and toxin neutralization tests . Patients' ages were 11 to 81 years . Most were white women . Six had abrupt onset of illness . Headaches, fever, myalgias, and exanthems were among the presenting complaints . The disease seemed milder than classic louse-born epidemic typhus, but in some instances, it was life-threatening . All patients responded to tetracycline or chloramphenicol . This entity probably is more common than reported, is difficult to recognize, and is produced by an organism seemingly identical to that producing louse-born epidemic typhus. Lab Anim Sci, 1981 Jun, 31(3), 289 - 91 Scrub Typhus antibody in cynomolgus monkeys (Macaca fascicularis) in Malaysia; Heisey GB et al.; Using an indirect immunofluorescence technique, sera from 113 cynomolgus monkeys (Macaca fascicularis), trapped in Peninsular Malaysia, were screened for the presence of antibody to six prototype strains of Rickettsia tsutsugamushi combined into three polyvalent groupings: I--Karp, TA716, and TA763; II--Gilliam; and III--TA678 and TH1817 . Fifteen percent (17/113) of the monkeys had antibody titers greater than or equal to 1:50 to one or more of the antigenic groups . Although a titer greater than or equal to 1:150 is generally considered indicative or prior Rickettsia tsutsugamushi infection, we selected a less than 1:25 titer as a conservative standard to insure non-infected animals . Using this criterion, 62 (55%) of the 113 monkeys were accepted for use in scrub typhus studies . The high prevalence of antibody to scrub typhus in the semi-arboreal cynomolgus monkey is in marked contrast to the low prevalence reported in the strictly arboreal silvered leaf monkeys (Presbytis cristatus) . The results of this study indicate that cynomolgus monkeys should be rigorously screened for evidence of prior infection before they are included in experimental scrub typhus studies. Infect Immun, 1981 May, 32(2), 525 - 33 Antigens of scrub typhus rickettsiae: separation by polyacrylamide gel electrophoresis and identification by enzyme-linked immunosorbent assay; Eisemann CS et al.; Antigens of plaque-purified Rickettsia tsutsugamushi strains Gilliam, Karp, and Kato were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and were analyzed by an enzyme-linked immunosorbent assay . Six antigens were identified in each of the three prototype strains; in strain Gilliam, these antigens were located in the cell envelope fraction of the organisms . Reactivity of these isolated antigens with homologous or heterologous immune sera indicated that different macromolecules existed in all three strains, although they exhibited very similar mobilities during electrophoresis . Antigens of strain Gilliam reacted equally well with antibodies directed against Gilliam, Karp, or Kato rickettsiae . However, strains Karp and Kato each had two distinct antigens which did not react with heterologous antisera . R . tsutsugamushi antigens retained immunogenicity after electrophoresis, and antisera raised against them reacted with intact organisms and exhibited specificity in reactions with isolated antigens. Infect Immun, 1981 Mar, 31(3), 1239 - 50 Macrophages in resistance to rickettsial infections: early host defense mechanisms in experimental scrub typhus; Nacy CA et al.; Several early nonspecific host defense mechanisms were examined in resistant (BALB/c) and susceptible (C3H/He) mice after intraperitoneal inoculation with Rickettsia tsutsugamushi strain Gilliam . Inflammatory exudates were formed in both mouse strains in response to rickettsial inoculation, but the inflammatory response of C3H animals was delayed several days, and influx of peroxidase-positive macrophages occurred late in infection . Peritoneal cells of C3H mice became progressively infected, with 40% of both macrophages and lymphocytes containing intracellular rickettsiae by day 10 . The early flammatory response of BALB/c mice was unexpectedly associated with a low percentage of infected peritoneal cells (1 to 2%) . In vitro, no difference was detected in ability of resident macrophages of either strain to support the growth of R . tsutsugamushi or to become activated by treatment with lymphokines for rickettsiacidal activity . In vivo, however, macrophages from C3H mice inoculated with Gilliam were not activated on days 6 and 7 after infection, whereas BALB/c macrophages were continuously activated beginning on day 4 . The lack of in vivo C3H macrophage activation was not secondary to deficient lymphokine production by infected lymphocytes, as levels of lymphokines produced by peritoneal lymphocytes of both strains were similar and peaked on day 7 after infection . Susceptibility to infection appears to be related to defective regulation of macrophage responses rather than to defects in macrophage function. Infect Immun, 1981 Mar, 31(3), 1014 - 22 Host defenses in experimental scrub typhus: inflammatory response of congenic C3H mice differing at the Ric gene; Jerrells TR et al.; Two strains of C3H mice differed in their susceptibility to lethal infection with Rickettsia tsutsugamushi strain Gilliam . Adult C3H/RV mice were markedly more resistant to lethal infection than C3H/HeDub mice, and both were histocompatible as assessed by mixed-lymphocyte cultures and graft-versus-host responses . The inflammatory response of susceptible C3H/HeDub mice to intraperitoneal infection was evident approximately 5 days postinfection, and the magnitude of the cellular influx increased until death of the animal . The inflammation consisted of an early polymorphonuclear leukocyte response, followed by a mononuclear cell influx which persisted until death of the animal . The C3H/RV mice evidenced similar kinetics of cell influx, but the inflammatory response was significantly reduced in magnitude, and the response of C3H/RV animals to Gilliam was predominantly mononuclear in nature, with little influx of polymorphonuclear leukocytes into the peritoneal cavity . C3H/RV mice were rendered susceptible to Gilliam infection by induction of a nonspecific inflammation with thioglycolate if given 3 days after infection . Conversely, treatment of C3H/HeDub mice with indomethacin, an anti-inflammatory agent, prolonged survival after infection with Gilliam . The results of this study indicate that genetic resistance to Gilliam is not due simply to a greater host response to infection or, conversely, that susceptibility is due to a host response quantitatively lacking in a cellular component necessary for antirickettsial immunity. Ann Acad Med Singapore, 1981 Jan, 10(1), 107 - 11 Scrub typhus 1980; Twartz JC; Scrub typhus is a widespread and at times serious infection in Asia . If results from central Malaysia can be applied, it appears to be economically important . Diagnosis is often difficult and treatment prone to fail if short courses of antibiotics are used . Prophylaxis is the key area of research with the development of a vaccine being the ultimate goal. Zh Mikrobiol Epidemiol Immunobiol, 1981 Jan, (1), 28 - 34 {Luminescent-serologic analysis of the antigenic interrelationship between R . canada and classic representatives of rickettsiae of the typhus group}; Balaeva NM et al.; The results of studying the antigenic relationships of R . canada, a new Rickettsia species, and classical Rickettsia species of the typhus group are presented . The study was carried out by luminescent serological analysis with the use of corpuscular antigens and the live infectious agent cultures . R . canada and Rickettsiae of the typhus group were similar in their antigenic structures; this, however, could be revealed only in the study of the live cultures of the infectious agents . The study of corpuscular antigens revealed unilateral relationship: R . prowazeki antigen could be detected with homologous and heterologous sera, R . canada antigen with homologous serum only . In the CFT and the agglutination test corpuscular R . canada antigen reacted with homologous and heterologous sera . The study of the live cultures of the infectious agents revealed that different R . prowazeki and R . typhi strains vary in the degree of their similarity to R . canada. Infect Immun, 1981 Jan, 31(1), 276 - 88 Partial purification and characterization of the major species-specific protein antigens of Rickettsia typhi and Rickettsia prowazekii identified by rocket immunoelectrophoresis; Dasch GA et al.; Species-specific antigens from Rickettsia typhi and Rickettsia prowazekii were readily solubilized by French pressure cell extraction or sonication of Renografin density gradient-purified rickettsiae and were identified by rocket immunoelectrophoresis . As measured by quantitative rocket immunoelectrophoresis, the species-specific typhus rocket antigens (STRAs) appeared to be proteins; they were denatured by heating at 56 degrees C for 30 min but not by 50 degrees C treatment, and they were sensitive to pronase and trypsin but were not affected by periodate oxidation, glycosidases of various specificities, phospholipase A, or lipase . STRAs from both R . typhi and R . prowazekii were separated from common antigens by DE52 column chromatography of 100,000-X-g supernatant fractions of rickettsial extracts . The purified STRAs were characterized by crossed immunoelectrophoresis, by polyacrylamide gel electrophoresis on Davis and sodium dodecyl sulfate gels, and by an enzyme-linked immunosorbent assay . The two purified STRAs were proteins with similar native electrophoretic mobilities in agarose and polyacrylamide gels, and these proteins had similar polypeptide patterns on sodium dodecyl sulfate gels . Most of the STRA activity migrated as a single protein band on sodium dodecyl sulfate-polyacrylamide and Davis polyacrylamide gels, although minor protein bands with STRA activity were also detected . The major STRA proteins constituted 10 to 15% of the total cellular protein of R . typhi and R . prowazekii . According to sensitive enzyme-linked immunosorbent assay titrations, the STRA of R . prowazekii had substantial cross-reactivity with rabbit antiserum prepared against R . typhi, as shown also by rocket immunoelectrophoresis, whereas the STRA of R . typhi reacted only very weakly with antiserum prepared against R . prowazekii according to the enzyme-linked immunosorbent assay and not at all according to rocket immunoelectrophoresis. Am J Trop Med Hyg, 1981 Jan, 30(1), 253 - 63 Experimental infection of ectoparasitic arthropods with Rickettsia prowazekii (GvF-16 strain) and transmission to flying squirrels; Bozeman FM et al.; Epizootiologic studies conducted during the past few years showed the existence of widespread natural infection of the southern flying squirrel, Glaucomys volans, with epidemic typhus rickettsiae, Rickettsia prowazekii . The ecological findings strongly implicated transmission of the etiologic agent by an arthropod vector . Studies were conducted under controlled laboratory conditions to determine whether ectoparasites naturally associated with flying squirrels (squirrel fleas, lice, mites and ticks) were capable of acquiring, maintaining and transmitting the infection . Also studied were the cat flea, oriental rat flea and the human body louse . Flying squirrels inoculated with the GvF-16 strain of R . prowazekii circulated rickettsiae in their blood for 2-3 weeks, thus providing ample opportunity for arthropods feeding on them to become infected . The results with Dermacentor variabilis ticks indicated that the rickettsiae did not consistently survive in this insect and were not passed to the eggs of adult females that had been infected subcuticularly . Mites became infected by feeding on infectious blood but failed to sustain the infection . Also, mites fed on an infected flying squirrel did not transmit the infection to a normal squirrel . Squirrel, cat, and oriental rat fleas readily became infected by feeding on a rickettsemic host or on infectious blood through membranes, but failed to transmit the infection to susceptible flying squirrels . In the studies with flying squirrel lice, however, transmission of epidemic typhus from infected to uninfected flying squirrels was demonstrated . Infection of the human body louse with the GvF-16 flying squirrel strain of R . prowazekii was similar to that previously observed with classical human strains, viz., multiplication of the rickettsiae and excretion in the feces. J Clin Microbiol, 1981 Jan, 13(1), 214 - 6 Detection of typhus antibodies by latex agglutination; Hechemy KE et al.; A latex test for assay of antibodies to endemic and epidemic typhus rickettsiae is simple, group-specific, sensitive, and reproducible . Cross-reactivity within the typhus group was extensive. Infect Immun, 1980 Oct, 30(1), 219 - 23 Epidemic typhus infection in cynomolgus monkeys (Macaca fascicularis); Gonder JC et al.; A nonhuman primate model of clinical Rickettsia prowazekii infections was developed in cynomolgus monkeys (Macaca fascicularis) . Monkeys infected intravenously with 10(7) plaque-forming units developed clinical signs of illness and pathological changes characteristic of epidemic typhus infection in humans . Increases in total leukocyte counts, serum alkaline phosphatase, blood urea nitrogen, and serum glutamic pyruvate transaminase values were observed . Microscopic examination revealed typical typhus nodules in the brains of two monkeys that died . These data indicated that the cynomolgus monkey is a suitable model for study of the pathogenesis of epidemic typhus infection and may prove valuable in the evaluation of candidate R . prowazekii vaccines. Jpn J Med Sci Biol, 1980 Oct, 33(5), 277 - 82 Leptotrombidium (Leptotrombidium) Umbricola, new species, a probable vector of scrub typhus in Peninsular Malaysia; Nadchatram M et al.; Leptotrombidium (Leptotrombidium) umbricola, described here as a new species, is a member of the L . (L.) deliense group and most closely resembles L . (L.) vivericola . L . (L.) umbricola was collected from the ground surface and from animal hosts, in similar habitats to the scrub typhus vector, L . (L.) deliense . The host and habitat distribution records and the Rickettsia tsutsugamushi infection rates within unengorged specimens suggest that L . (L.) umbricola may be an important vector of scrub typhus in Peninsular Malaysia. Jpn J Med Sci Biol, 1980 Oct, 33(5), 263 - 70 Variation in populations of chigger vectors of scrub typhus in developing oil palm areas of different ages; Dohany AL et al.; The populations of scrub typhus vector chiggers were compared in two developing oil palm areas, one 5 years old and the other 7 years old at the inception of the study . Both areas were located within the same oil palm scheme in central Peninsular Malaysia . Leptotrombidium (L.) deliense, a principal vector of scrub typhus in Malaysia, was found in reduced numbers in the older oil palm habitat . This reduction is attributed to changes in the microhabitat, specifically the elimination of grasses between the oil palm trees due to canopy shading and to cultural practices. Am J Trop Med Hyg, 1980 Sep, 29(5), 989 - 97 Prevention of scrub typhus . Prophylactic administration of doxycycline in a randomized double blind trial; Olson JG et al.; We conducted a prospective randomized double blind study on the effects of doxycycline as a prophylactic antibiotic against scrub typhus . A total of 1,125 military subjects was followed for periods as long as 5 months of exposure in a hyperendemic focus in the Pescadores Islands of Taiwan . Oral 200 mg doses of doxycycline (Vibramycin) or placebo were given once each week throughout the trial . The incidence rate of scrub typhus in the placebo group was 2.5 times greater than that of the group taking doxycycline (P = 0.11) . When subjects who failed to comply with scheduled administration of doxycycline were removed from the analysis, the incidence rate of scrub typhus in the control group was five times greater than that in the drug group (P = 0.04) . The rates of infection with Rickettsia tsutsugamushi and of sick call reports were the same in experimental and control groups . The drug was well tolerated in pretrial tests and complaints were negligible during the conduct of the trial . Doxycycline appears to be an excellent antibiotic for the prevention of scrub typhus among personnel exposed to high risk of infection with R . tsutsugamushi. J Clin Microbiol, 1980 Sep, 12(3), 343 - 50 Use of a sensitive microplate enzyme-linked immunosorbent assay in a retrospective serological analysis of a laboratory population at risk to infection with typhus group rickettsiae; Halle S et al.; A microplate enzyme-linked immunosorbent assay (ELISA), developed for the detection of antibodies to typhus group rickettsiae, was used to analyze human sera from individuals engaged directly or indirectly in rickettsial research . The earliest serum available from each of 112 individuals was tested for immunoglobulin M (IgM) and IgG antibodies against Rickettsia typhi and Rickettsia prowazekii by ELISA at a 1:500 dilution . In at least one assay, nine sera had ELISA optical densities of greater than 0.2, which were above the mean optical densities plus three standard deviations of the other 103 sera . Three of the positive sera were from individuals with known clinical cases of typhus infection . The other sera with predominantly IgG titers were from individuals with extended laboratory exposure to rickettsiae or histories of typhus vaccination, or both . During continued serological surveillance, eight additional people with repeated occupational exposure to typhus rickettsiae had seroconversions in the ELISA to optical densities of greater than 0.2 . No apparent clinical illness occurred in two individuals, whereas six clinical cases of infection occurred in others subsequent to accidental laboratory autoinoculation (one) or aerosol exposures (five) . In the clinical infections, antibodies were first detected at 7 days, but in subsequent sera, rises and declines in titers were quite variable and were influenced by vaccination, relapse, and time and extent of antibiotic therapy . In primary infections the sera of several individuals who received immediate antibiotic therapy had brief strong IgM responses without pronounced increases in IgG . In contrast, much higher IgG levels were attained in three cases in which relapse occurred, the individual had previously been immunized, or treatment had been delayed . The microplate ELISA proved to be a highly sensitive and reliable test for detection of the human serological response to typhus antigens. J Immunol, 1980 Sep, 125(3), 1395 - 9 Host defenses in experimental scrub typhus: mapping the gene that controls natural resistance in mice; Groves MG et al.; Natural resistance of mice to lethal ifections of Rickettsia tsutsugamushi, strain Gilliam, is controlled by a single, autosomal, dominant gene, which we have designated Ric, with r and s representing the resistant nd susceptible alleles, respectively . Using three sets of recombinant inbred mouse strains (BXD, BXH, and BXJ), the Ric locus was mapped to Chromosome 5 closely linked to the retinal degeneration (rd) locus . This linkage was confirmed by a backcross analysis . Based on the RI strains and the C57BL/6Ty-le congenic strain (the only proven Ric-rd cross-over), we estimate the recombination frequency between Ric and rd to be 0.015 . Three presumptive Ric-rd recombinants detected among 93 backcross mice may represent caes of incomplete penetrance of the resistance allele rather than recombination . Analyis of th C57BL/6JTy-le congenic strain indicates that Ric is proximal to rd on Chromosome 5 . If so, the correct gene order is Pgm-1-W-Ric-rd-Gus. Southeast Asian J Trop Med Public Health, 1980 Sep, 11(3), 352 - 4 Species distribution of trombiculid mites on murine rodents in Rangoon, Burma; Nadchatram M et al.; Ectoparasite collections from over 12,000 commensal rodents and shrews in Rangoon were examined . Rattus rattus, R . norvegicus, R . exulans and Bandicota bengalensis were found to host 12 species of trombiculid mites . Ascoschoengastia indica was the most abundant trombiculid found representing 84% of the total sample of 15,000 chiggers . This species (A . indica) may be of considerable significance as a vector of murine typhus. Southeast Asian J Trop Med Public Health, 1980 Jun, 11(2), 232 - 9 Rodent and scrub typhus survey in a ricefield at Kramat Tunngak area, Tanjung Priok, Jakarta, Indonesia; Lim BL et al.; Trapping of small mammals in a ricefield at Kramat Tunggak around Tanjung Priok in Jakarta city, was carried out from July 1977 through June 1978 . Of three species of rodents, R.argentiventer was found to be the predominant species in the ricefield . R.r.diardii was an intermittent resident, and the presence of R.norvegicus was interesting observation . S.murinus, a house shrew, was also present . R.argentiventer was the dominant species during the periods when the rice grains were available as a source of food . Infestation with Gamasid mites and non-vector chiggers was found common in all rodent species examined . R . argentiventer was the only species found infested with the classical scrub typhus vector (L . (L.) deliense) . The density and mean chigger-load of the scrub typhus vector chiggers were found to be high in stages 4 and 5 of the ricefields when the micro-habitats were favourable . The oriental rat flea (X . cheopis) was found infesting all species of rodents. Southeast Asian J Trop Med Public Health, 1980 Jun, 11(2), 220 - 6 Scrub typhus survey of Biak and Owi islands: ectoparasites of small mammals and rickettsial isolations; Hadi TR et al.; A survey of smnall mammals and their ectoparasites was conducted on the islands of Biak and Owi, Indonesia, in August 1976 . Two species of chiggers known to serve as vectors of scrub typhus were found: Leptotrombidium (Leptotrombidium) deliense from Rattus exulans, R . ruber, and R . r . septicus; L . (L.) flectcheri from R . exulans, R . leucopus and R . r . septicus . Rickettsia tsutsugamushi was isolated from the spleens of R . exulans and R . r . septicus . The favored ecotype of the chigger and rat hosts of R . tsutsugamushi appeared to be coarse, low-lying native vegetation on a porous coralline soil . These and similar nearby coral islands should be considered high risk areas for scrub typhus. J Clin Microbiol, 1980 Jun, 11(6), 584 - 8 New paper enzyme-linked immunosorbent technique compared with microimmunofluorescence for detection of human serum antibodies to Rickettsia tsutsugamushi; Crum JW et al.; A new paper enzyme-linked immunosorbent assay was developed for the screening and titration of human serum antibodies against the scrub typhus rickettsia, Rickettsia tsutsugamushi . The objetive was to provide a relatively simple method for antibody screening which required neither sophisticated laboratory equipment nor a high degree of technological skill . The technique develops an enzyme product from filter paper saturated with a 5-aminosalicylic acid substrate and enzymatically reacted with a commerically available anti-human immunoglobulin G peroxidase conjugate . The product of the enzymatic reaction can be interpreted visually . Comparison of 351 human sera tested by the immunofluorescent and paper enzyme-linked immunosorbent assays against a three-antigen pool of the Karp, Kato, and Gilliam strains of R . tsutsugamushi demonstrated an agreement of 96% . The sensitivity of the paper enzyme-linked immunosorbent assay as compared to immunofluorescence was 98.2%, and the specificity was 94.4%. J Clin Microbiol, 1980 May, 11(5), 503 - 7 Development and characterization of high-titered, group-specific fluorescent-antibody reagents for direct identification of rickettsiae in clinical specimens; Hebert GA et al.; Rabbits were inoculated with purified antigen preparations of Coxiella burnetii and representative species of the spotted fever and typhus groups of rickettsiae . Their antibody responses were monitored by complement fixation tests; high-titered antisera were fractionated with ammonium sulfate and then labeled with fluorescein isothiocyanate by the dialysis method . The conjugates had homologous 3+ staining titers of 1:256 to 1:2,048 and did not exhibit nonspecific staining . The Rickettsia rickettsii, R . conorii, and R . akari conjugates reacted only with rickettsiae of the spotted fever group; the R . canada, R . prowazekii, and R . typhi conjugates were specific for the typhus group rickettsiae; and the C . burnetii conjugate stained only homologous organisms . One of these conjugates (R . rickettsii) is currently being used to identify rickettsiae in clinical specimens and has already proven its value as a diagnostic tool. Infect Immun, 1980 Apr, 28(1), 295 - 7 Gamma-irradiated scrub typhus immunogens: analysis for residual, replicating rickettsiae; Eisenberg GH Jr et al.; Scrub typhus immunogens that received inadequate gamma radiation contained residual, viable rickettsiae . The presence of these organisms in the host was masked by the rapid immune response elicited by the large number of inactivated rickettsiae . Transfer of homogenized spleen cells from immunized mice to normal syngeneic recipients provided a sensitive technique for the detection of these viable, replicating organisms. Southeast Asian J Trop Med Public Health, 1980 Mar, 11(1), 71 - 80 A study of small mammals in the Ciloto field station area, West Java, Indonesia, with special reference to vectors of plague and scrub typhus; Liat LB et al.; From June 1977 to June 1978 a study of smal mammals was carried out in the Ciloto field station area, West Java, Indonesia by the WHO Vector Biology and Control Research Unit-II . The objectives of the investigations were to determine the diversity and density of rodent species, to find potential plague and scrub typhus vectors and to study their host-parasite relationships . In the 13 month period a total of 6 species of murids were identified; two species of campestral rats (R . tiomanicus and R . argentiventer), one species of peri-domestic (R . exulans), one species of domestic (R.r . diardii), and two species of forest rats (R . bartelsii and R . bukit) . In addition, three species of insectivores (Suncus murinus, Hylomys suillus and Crocidura monticola), and one species of carnivore were found . Of the three habitats studies (mixed, ricefield and lalang), 10 species of small mammals were found in the mixed while four species of commensal murids were found in both the ricefield and the lalang . Of the four commensal murid species R . exulans had the highest density . R . tiomanicus was common but not abundant, and least common was R . argentiventer . R.r . diardii was occasionally found in the field . The mean litter size of gravid R . tiomanicus was 7.1, R . exulans 4.3, R . argentiventer 7.5 and R.r . diardii 9 . Male R . tiomanicus, R . argentiventer and R.r . diardii with spermatozoa present in animals over 55 gm . Animals of less than 50 gm had no sperm . In R . exulans spermatozoa were present in specimens weighing 24-66 gm . No sperm were detected in those below 20 gm . The flea index of Xenopsylla cheopis and Stivalius cognatus as determined for R . tiomanicus was 0.3 and 2.3;l for R.r . diardii 2.2 and 1.7; for R . exulans 0.3 and 0.5; and for R . argentiventer 0.4 and 1.7 respectively . S . cognatus had a significantly higher density than X . cheopis among the campestral and peridomestic rats, but the density of X . cheopis was significantly in the domestic rat . Overall infestation rates were equally high in both mixed and lalang habitats, but low in the ricefield . Flea indices were highest in the mixed habitat, lower in lalang, and lowest in ricefield . The putative vector of scrub typhus (Leptotrombidium (L.) deliense) was quite prevalent on campestral rats, less so on domestic ones and least on peridomestic . Overall infestation rates were equally high in both mixed and lalang habitats and low in the ricefield . Chiggers load per animal was significantly higher in the mixed habitat, lower in lalang and lowest in the ricefield. Infect Immun, 1980 Mar, 27(3), 730 - 8 Mechanisms of immunity in typhus infection: analysis of immunity to Rickettsia mooseri infection of guinea pigs; Murphy JR et al.; To study the mechanisms of immunity to Rickettsia mooseri (R . typhi) infection, sera and splenic cells collected from nonimmune and immune guinea pigs were inoculated separately into syngeneic nonimmune recipients which were subsequently challenged intradermally . Protection was measured by comparing the course of the challenge infections of recipients with infections initiated with the same rickettsial inocula in nonimmune animals . Recipients of splenic cells collected 21 days after donor infection were protected from lesion development at sites of intradermal challenge and showed fewer rickettsiae in their kidneys . Cells obtained from nonimmune donors did not protect against either skin lesion development at sites of challenge or kidney infection . Antibody-containing sera collected 21 days after donor infection, but not normal sera, reduced levels of kidney infection, but immune sera did not protect against the development of lesions at sites of intradermal challenge . It was concluded that both immune sera and immune splenic cells possess capacities to effect a partial control of the systemic phase of R . mooseri infection in guinea pigs, but that immune splenic cells possess a capacity not shared by immune sera, i.e., the capacity to protect from infection at local sites of intradermal inoculation. Am J Trop Med Hyg, 1980 Mar, 29(2), 277 - 84 Evidence of Rickettsia prowazekii infections in the United States; McDade JE et al.; From January 1976 through January 1979 serum specimens from 1,575 individuals were received at the Center for Disease Control and tested for antibodies to rickettsiae . Of these, sera from eight persons gave serological results indicative of recent infections with epidemic typhus rickettsiae (Rickettsia prowazekii) . Five of the persons were from Georgia, and one each was from Tennessee, Pennsylvania and Massachusetts . The illnesses occurred during the winter, chiefly in persons living in a rural environment . The clinical picture was compatible with louse-borne epidemic typhus . There was no apparent contact with human body or head lice, and no cases occurred in patient contacts, indicating that infection was not associated with the classic man-louse-man cycle of epidemic typhus . Two of the eight patients had contact with flying squirrels suggesting that they became infected from this known extrahuman reservoir of R . prowazekii. Am J Dermatopathol, 1980 Spring, 2(1), 39 - 45 The pied Piper of Hamelin . A medical-historical interpretation; Dirckx JH; A historical basis is proposed for the 13th-century legend of the Pied Piper, who led away the rats from the town of Hamelin and when refused payment for his services, led away 130 children and disappeared with them in the mountains . It is suggested that the children actually died in an outbreak of disease and were buried in a common grave at the site of the legendary disappearance . The association with rats points to a rodent-borne infection, and the pied (mottled) coat of the piper seems to indicate a disease causing conspicuous macular lesions . Historical and epidemiologic arguments are presented in favor of murine typhus as the predominant infection in the Hamelin epidemic. Bull Soc Pathol Exot Filiales, 1980 Jan-Feb, 73(1), 48 - 53 {3Autochthonous cases of murine typhus in France?}; Edlinger E; Three men native from Northern Africa, aged more than 40 years, but by their profession in France with narrow contacts to rats, present clinical signs of typhus . Serology (FCT and FAT) gives positive results with R . prowazeki and R . typhi which have a strait antigenic community . Following assays of absorption of the sera by the two antigens and light differences of titers we conclude that two cases are Brill-Zinsser illnesses, but one is really an autochtone case of murin typhus . The last affirmation is confirmed by the detection of specific IgM-antibodies. Trans R Soc Trop Med Hyg, 1980, 74(2), 253 - 7 The longevity of antibody to Rickettsia tsutsugamushi in patients with confirmed scrub typhus; Saunders JP et al.; Serological surveillance for up to two years of 114 patients with laboratory confirmed scrub typhus showed that antibody to Rickettsia tsutsugamushi as demonstrated by the indirect fluorescent antibody test is short-lived . The mean reversion time from mean peak titre (1:499) was 48.9 weeks and the calculated annual reversion rate to a titre less than 1:50 was 61% . This can be used to estimate attack rates based on point prevalence of antibody . The relationship between antibody prevalence and attack rates observed by other workers was confirmed using this model . The possible uses of the finding and its implications in Malaysia are briefly discussed. Trop Geogr Med, 1979 Dec, 31(4), 519 - 24 Forecasting the onset of a scrub typhus epidemic in the Pescadores Islands of Taiwan using daily maximum temperatures; Olson JG; Daily maximum atmospheric temperatures were used to forecast the seasonal onset of scrub typhus in the Pescadores Islands of Taiwan . The day of the year on which the temperature first reached 30 degrees C was selected as the predictive base . Predictions for 1977 closely matched observed events . The model provides an easy and effective means to forecast the start of scrub typhus epidemics in the Pescadores Islands and could be used for such practical purposes as determining when prophylactic antibiotics should be administered to subjects whose risk of infection with Rickettsia tsutsugamushi is high. Southeast Asian J Trop Med Public Health, 1979 Dec, 10(4), 510 - 3 Vectors of scrub typhus and their hosts on a mature oil palm estate; Dohany AL et al.; L . (L.) deliense was the predominant vector of scrub typhus in a mature oil palm estate, but a small number of L . (L.) fletcheri (0.1% from rodents) and L . (L.) vivericola (0.02% from rodents and 8.0% from black plates) was also collected . Although good correlation between L . (L.) deliense collected from rodents and from black plates was not established, either method may serve as a general indicator of population fluctuations over a period of time . For the most part, the vectors of scrub typhus were limited to litter piles, and thus, the possibility of contracting scrub typhus within this type of habitat was minimal. Infect Immun, 1979 Nov, 26(2), 744 - 50 Host defenses in experimental scrub typhus: role of normal and activated macrophages; Nacy CA et al.; Resident peritoneal macrophage from BALB/c mice were infected in vitro with Rickettsia tsutsugamushi strain Gilliam, and rickettsial growth was estimated by microscopic examination of Giemsa-stained cells . Both number of infected macrophage per culture and number of intracellular rickettsiae per cell increased with time during culture . Treatment of rickettsiae with immune serum before infection macrophage cultures reduced the number of infected macrophage by 50% . Macrophage treated in vitro with lymphokines were able to suppress rickettsial growth in the absence of detectable antibody and exhibited a 75% reduction in infection compared with normal macrophage . We also obtained activated macrophage from immune mice and found that they were refractory to in vitro rickettsial infection . Macrophage populations activated in vitro or in vivo contained a small percentage of cells which supported unrestrained growth of rickettsiae . These data suggest that an early immunological event in experimental scrub typhus infection may be the development of activated macrophage capable of suppressing rickettsial proliferation before the appearance of circulating antibody. Infect Immun, 1979 Oct, 26(1), 131 - 6 Gamma-irradiated scrub typhus immunogens: broad-spectrum immunity with combinations of rickettsial strains; Eisenberg GH Jr et al.; Scrub typhus immunogens were prepared from Rickettsia tsutsugamushi strains Karp, Kato, Gilliam, Kostival, and Buie by exposing frozen infected yolk sac suspensions to 300 krad of gamma radiation . Mouse protection tests showed that each of the irradiated immunogens protected C3H/HeDub mice against high challenge levels of Karp and Gilliam, but that none of these single-strain immunogens were capable of protecting against all five of the challenge strains . Broad-spectrum protection was achieved by using combinations of three strains of irradiated rickettsiae in a vaccination regimen of three injections at 5-day intervals . A comparison of vaccination efficacy employing three such combinations (Karp-Gilliam-Kato, Karp-Kostival-Kato, and Buie-Kostival-Kato) indicated that both sequential administration of strains on successive vaccination days and multiple injections of trivalent mixtures produced protective responses superior to those obtained with single-strain immunogens . Trivalent mixtures of rickettsiae exhibited a striking synergistic effect on the immune response of C3H/HeDub mice and elicited a protective response against Kato challenge that could not be obtained with any single-strain immunogen . Mice vaccinated with the trivalent Karp-Gilliam-Kato immunogen resisted challenge with more than 10(3) 50% mouse lethal doses of Karp and Gilliam for 12 months, and were resistant to similar levels of challenge with Kato and Buie for 6 months. Fortschr Med, 1979 Sep 6, 97(33), 1391 - 4 {Surgical therapy of intestinal complications in abdominal typhus}; Ramirez R et al.; At our clinic 185 patients with severe typhoid fever were treated . In 51 cases severe complications required a surgical therapy: 24 times bleeding of small or large intestine, 14 times perforation of the bowel and 13 times acute typhoid cholecystitis . Lethality of typhoid peritonitis with perforation is nowadays--inspite of specific therapy with antibiotics--still between 40% and 50%; lethality at our clinic was 37.5% . Dangerous complications are bleeding and re-perforation, which require an aggressive surgical procedure. J Clin Microbiol, 1979 May, 9(5), 645 - 7 Rickettsial hemolysis: rapid method for enumeration of metabolically active typhus rickettsiae; Walker TS et al.; A new assay is described for enumerating biologically active typhus rickettsiae (Madrid E strain), based on adsorption of rickettsiae to erythrocytes in the presence of NaF (which allows adsorption but not lysis) and lysis in the presence of anti-Rickettsia prowazeki immune serum (which allows only a single round of lysis) . The number of lysed erythrocytes is then used to estimate the number of active rickettsiae. Infect Immun, 1979 May, 24(2), 387 - 93 Mechanisms of immunity in typhus infection: adoptive transfer of immunity to Rickettsia mooseri; Murphy JR et al.; When nonimmune guinea pigs are inoculated intradermally (i.d.) with Rickettsia mooseri (R . typhi), the rickettsiae replicate at the site of inoculation, leading to the development of a grossly observable lesion . In contrast, guinea pigs which have recovered from R . mooseri infection are resistant to challenge and prevent both rickettsial growth and the formation of lesions . To study the mechanisms of this immunity, sera or splenic cells collected from nonimmune or immune guinea pigs were inoculated separetely into nonimmune recipients . Splenic cells collected from immune donors protected R . mooseri-naive recipients from i.d . challenge as measured by control of rickettsial growth and by prevention of development of lesions at i.d . sites of inoculation . In contrast, serum from immune and nonimmune doners failed to protect nonimmune recipients by either criterion. Zh Mikrobiol Epidemiol Immunobiol, 1979 May, (5), 52 - 5 {Importance of humoral immunity indices in determining the Rickettsia prowazekii carrier state}; Ignatovich VF et al.; Experiments showed the possibility of making indirect conclusions concerning rickettsial carrier state by the method of determination of complement-fixing antibodies to R . prowazeki in the blood serum . Though not indicative of carrier state in individual animals, these antibodies, their dynamics and titers gave the evidence of group carrier state in cotton rats in respect of the causative agent of typhus . The number of animals carrying R . prowazeki increased with the rise of antibody titers . Negative seroconversion indicated the elimination of the causative agent from the body of the animal . The experimental results were confirmed by the data on the dynamics of the immunological structure of population, as well as by information contained in the literature on this problem. Med J Aust, 1979 Apr 21, 1(8), 451 - 4 Queensland tick typhus in Sydney: a new endemic focus; Campbell RW et al.; A new endemic focus of Queensland tick typhus was defined when two cases of Rickettsia australis infection were recognized in Sydney . Although the tick vector is distributed throughout coastal, eastern Australia these are the first cases diagnosed south of Lismore, New South Wales. Zentralbl Bakteriol {B}, 1979 Mar, 168(2), 1 - 17 {Seasonal and periodic rhythms of infectious diseases (author's transl)}; Knorr M et al.; The causes of epidemics are plainly not the pathogens alone as was initially assumed by Koch's school, predisposition and constitution of the population proved to be equally important . Ever since ancient times problems linked with the "constitutio epidemica" have been topical; the "physis", the "natura hominis" and the invironment of man play an increasingly important role in the symptomatology of disease, as can be gathered from such early documents as the "Corpus hippocraticum" . Fracastoro distinguished between contagious and non-contagious epidemics . The casual organisms were considered to be miasmas -- noxious emanations -- or "contagia" i.e . likewise toxic substances . Questions concerning the origin of these miasmas turned attention to the environment (air, soil, water) and even led to astrological medicine . Not until the Renaissance were attempts made to differentiate the usual global words for epidemic, such as "loimos", "lues" and "pestis" with the result that a symptom was used more and more to designate a disease . For example, the symptom fever led to the designation "three-day fever" or "four-day fever", "typhus fever" . This terminology made a differential diagnosis difficult to establish, thwarted selection measures to check epidemics and the medical world was thus helpless in explaining the causal agents and the phenomena of epidemics . This is illustrated by some epidemiological examples (ergotism, scurvy, yellow fever, English sweat, diphtheria and malaria) . In this connection the "morbus novus", the transformation of the pathogen and the change of the pathogen is discussed . Many questions still left unanswered regarding the seasonal incidence, the fluctuation and disappearance of epidemics over decades or even centuries lead more frequently to sociomedical considerations with respect to the victims of epidemics, their predisposition, constitution and environment exposure term "hospital gangrene" with the modern term "hospitalism", we are not dealing with a transformation but a change of the pathogen . The impressive effects produced by antibiotics resulted in carelessness and along with the unprecedented advances in medicine and engineering we forgot to bear in mind that almost all great steps forward have an adverse side . Hygiene and practical medicine have only made a modest beginning in establishing the contact which should indeed be a matter of course in the hospital. Am J Trop Med Hyg, 1979 Mar, 28(2), 387 - 95 A comparison of the complement fixation, indirect fluorescent antibody, and microagglutination tests for the serological diagnosis of rickettsial diseases; Newhouse VF et al.; Three techniques for the serological diagnosis of Rocky Mountain spotted fever were compared by testing 417 sera from 178 patients who very probably did not have rickettsial infections and 88 sera from 41 patients who very probably had Rocky Mountain spotted fever (SF) . The techniques were complement fixation (CF), indirect fluorescent antibody (IFA), and microagglutination (MA) . To avoid possible degradation during unnecessary purification, the antigens were prepared by methods that were as simple as possible . In the CF tests of 417 sera from patients with nonrickettsial diseases there was only one titer of 8 and none at higher dilutions, whereas with the IFA and MA tests 4-8% of the sera reacted with SF antigens and 4-20% reacted with murine typhus (MT) antigens; the evidence indicated that these reactions were not caused by specific rickettsial antibody . With the SF sera, it could be seen that the IFA test was the most sensitive and the MA test was the least sensitive at each interval after infection . Moreover, the IFA results showed the least number of confusing cross-reactions with MT antigens and the MA test showed the most . The relative advantages of the three tests in serodiagnosis of rickettsial diseases are discussed. MMW Munch Med Wochenschr, 1979 Feb 9, 121(6), 209 - 12 {Boutonneuse fever in tourists as a model for clinical diagnosis of rickettsioses (author's transl)}; Eichenlaub D; Case histories of boutonneuse fever are described in order to exemplify major characteristics of most rickettsioses: recent travel history, feverish illness with severe headache, skin eruptions and histological findings . Up-to-date informations concerning the epidemiologic situation of typhus, scrub typhus and Rocky Mountain spotted fever are given . The characteristics of Q fever and the possibility of rickettsial laboratory infections are pointed out. Am J Epidemiol, 1979 Feb, 109(2), 236 - 43 Changing risk of scrub typhus in relation to socioeconomic development in the Pescadores islands of Taiwan; Olson JG et al.; Long term changes in risk of Rickettsia tsutsugamushi infection among civilian residents of the Pescadores Islands of Taiwan were associated with changing social conditions . Age specific incidence rates of scrub typhus in the Pescadores before 1940 were highest among children under 5 years of age . Rickettsiae can be demonstrated in vectors, wild animals continue to be infected and scrub typhus occurs in military personnel . A serologic survey for antibody to R . tsutsugamushi was conducted during 1975 and 1977 and failed to show evidence of previous infection among children . Two events appear to be associated with the decreased incidence of rickettsial infection in the young: increased urbanization and increased enrollment in schools . Both changes accompanied socioeconomic development which took place in the islands during the past 50 years . Prevalence of antibody to R . tsutsugamushi continues to be equal in the sexes and is undoubtedly due to similar occupational exposure of both sexes in fields and farms where vectors are numerous . The absence of apparent morbidity due to scrub typhus among the civilian populace was attributed to the mild nature of the disease caused by Pescadores strains, misdiagnosis and a lack of obligatory reporting. J Bacteriol, 1979 Jan, 137(1), 605 - 13 Ultrastructure of Rickettsia rhipicephali, a new member of the spotted fever group rickettsiae in tissues of the host vector Rhipicephalus sanguineus; Hayes SF et al.; Rickettsia rhipicephali is similar in ultrastructure to R . rickettsii while differing from other rickettsiae of the typhus group and of Q fever and others by its lack of a prominently reticulated cytoplasmic matrix and in the thickness of the inner osmophilic layer of the cell wall . In tissues of the tick vector Rhipicephalus sanguineus, R . rhipicephali had a mean length and width of 1.2 and 0.46 micrometer, respectively . It possessed a trilaminar cell wall with an adhering capsule-like layer . The trilaminar cell wall was approximately 12 to 18 nm thick; its inner osmophilic layer was thicker than that previously reported for other rickettsiae . The capsule-like layer varied from 7 to 18 nm thick . The plasma membrane was similar in structure, measurement, and appearance to that of other reported rickettsiae . The cytoplasm appeared to be composed of a finely granular, amorphous, ground substance and randomly dispersed ribosomes and lacked a reticular matrix or nuclear fibrils . In massively infected salivary glands and ovarial tissues of its tick vector, R . rhipicephali produced a low degree of histopathology which does not appear to affect the engorgement and egg-laying process of the ticks. J Clin Microbiol, 1979 Jan, 9(1), 38 - 48 Sensitive microplate enzyme-linked immunosorbent assay for detection of antibodies against the scrub typhus rickettsia, Rickettsia tsutsugamushi; Dasch GA et al.; A microtiter enzyme-linked immunosorbent assay (ELISA) has been developed for the titration of antibodies against scrub typhus in human and animal sera . Scrub typhus rickettsiae were grown in monolayers of irradiated mouse LM3 cells and separated from host cell materials by differential centrifugation, filtration through a glass filter (AP-20, Millipore Corp.), and isopycnic banding in Renografin density gradients . The scrub typhus ELISA antigens were obtained from the purified viable rickettsiae by French pressure cell disruption and addition of 0.2% Formalin to the soluble extract . Antisera prepared in rabbits against the prototype Karp, the Kato, and the Gilliam strains of scrub typhus were used to standardize the ELISA and to compare its sensitivity and specificity to that of the indirect fluorescent antibody test (IFA) . ELISA titers were measured as the greatest serum dilution showing an optical density 0.25 above controls or by the optical density achieved at a fixed serum dilution . The IFA and ELISA end point titers were quite similar, and all three measures of titer had comparable specificity for the strains of scrub typhus . No cross-reactions between the typhus and scrub typhus wera were observed by ELISA . Both the immunoglobulin M (IgM) and IgG antibody titers of 12 sequential sera from four patients with scrub typhus were obtained by IFA and ELISA . The IFA and ELISA end point titers for IgM and IgG had correlation coefficients of 0.91 and 0.97, respectively, whereas the ELISA optical density values at a serum dilution of 1:100 had slightly lower correlations with IFA titers (0.80 and 0.94) . Early rising IgM titers followed by rising IgG titers were demonstrated by ELISA in three patients with primary scrub typhus infections, whereas the IgG response predominated in a patient with a reinfection . It is concluded that the ELISA for scrub typhus is a very satisfactory alternative to the IFA test. Southeast Asian J Trop Med Public Health, 1978 Dec, 9(4), 489 - 93 Distribution of rats infected with Rickettsia tsutsugamushi (scrub typhus) in an edge habitat; Muul I et al.; No focalization of rats (Rattus tiomanicus and R . argentiventer) infected with Rickettsia tsutsugamushi could be discerned over a 500 m trapping transect at the border between a forest and lalang grass (Imperata cylindrica) . R . tiomanicus appeared to occupy 250 m of the transect on the average and had periods during which infections were observed which averaged 97 days . Calulations indicated that more than 50% of individuals become infected over their life-time . The high rate of infection in this and other areas described in earlier publications and the habits of the rats suggest that infected mites are densely and widely dispersed in the areas studied in Malaysia. Infect Immun, 1978 Dec, 22(3), 810 - 20 Mechanisms of immunity in typhus infection: some characteristics of intradermal Rickettsia mooseri infection in normal and immune guinea pigs; Murphy JR et al.; Rickettsia mooseri infection in skin at sites of intradermal inoculation was studied in nonimmune and immune guinea pigs with respect to dynamics of infection, localization of rickettsiae within tissues, and gross and microscopic pathology . Intradermal inoculation of R . mooseri into nonimmune guinea pigs resulted in gross lesions which, in magnitude, were directly related to the number of rickettsiae inoculated . The lesions progressively enlarged through 3 or 4 days and remained enlarged through at least 7 days . Histological examination revealed an early acute inflammation which progressed to a predominantly monocyte-macrophage inflammation and subsequently condensed into lymphocyte-containing granulomatous foci . Rickettsiae in the skin at sites of inoculation increased in numbers from 6 h through 3 days, in parallel with the increasing diffuse monocyte-macrophage inflammatory response, and then declined markedly on days 4 or 5 as ganulomatous foci appeared . Some rickettsiae, however, persisted through at least day 7 . Fluorescent-antibody studies suggested that R . mooseri infected only a subset of cells available, i.e., cells associated with the microvascular system . Dissemination of infection was demonstrated by the presence of rickettsiae in the skin at sites distant from the point of inoculation . Immune guinea pigs, made immune by intradermal infection with R . mooseri 12 days before intradermal challenge, displayed an accelerated response . The lesions were maximal by 24 to 48 h and subsequently regressed . The inflammatory response of immune guinea pigs was a greater magnitude than the response of similarly challenged nonimmune guinea pigs, and the respose from acute inflammation through the formation of granulomatous lesions was accelerated . The number of rickettsiae in the skin of immune guinea pigs declined steadily from the time of inoculation, until no rickettsiae were recovered on or after day 3 . Furthermore, dissemination of rickettsiae to sites in skin distant from the site of inoculation was not demonstrable . The results are discussed in terms of pathogenesis and of immunity to typhus. Infect Immun, 1978 Oct, 22(1), 298 - 300 Effects of temperature on the stability of Rickettsia tsutsugamushi and gamma-irradiated scrub typhus immunogens; Eisenberg GH Jr et al.; Unirradiated Rickettsia tsutsugamushi and a component of gamma-irradiated Karp immunogen required for homologous immunity were more stable than the immunogen component that elicited heterologous (Kato strain) protection. Infect Immun, 1978 Oct, 22(1), 233 - 46 External layers of Rickettsia prowazekii and Rickettsia rickettsii: occurrence of a slime layer; Silverman DJ et al.; Using a simple specific-antibody stabilization procedure on organisms gently liberated from their host cells, we have demonstrated by electron microscopy that Rickettsia prowazekii and Rickettsia rickettsii possess a coat of variable thickness, external to the outer leaflet of the cell wall and the structure designated by others as a "microcapsule," which corresponds most closely to the slime layer of certain other bacteria . Reactions in the methenamine silver and ruthenium red staining procedures and the failure to be visualized by standard procedures suggest that the slime layer is largely polysaccharide in nature . It is postulated that this slime layer accounts in large part for the large, electron-lucent, halo-like zone which is found by electron microscopy to surround organisms of the typhus and spotted fever groups in the cytoplasm of their host cells, that it may be the locus of some major group-specific antigens, and that it may function as an antiphagocytic mechanism, as an aid for attachment of rickettsiae to potential host cells, or both . Moreover, because the attenuated E strain of R . prowazekii has been shown to possess a substantial slime layer, the basis for attenuation is not likely to be a simple smooth-to-rough variation. J S Afr Vet Assoc, 1978 Sep, 49(3), 229 - 31 Wild rodents as laboratory models and their part in the study of diseases; Keogh HJ et al.; The paper describes the use of 14 South African wild rodent species as experimental models and demonstrates the proven value of many of these as laboratory animals in research on bacterial infections (plague, relapsing fever), rickettsial infections (tickbite fever, louse typhus), viral infections (poliomyelitis . Rift-Valley fever and other arbovirus infections, Lassa fever), fungal infections (histoplasmosis), parasitic infections (schistosomiasis) and in diabetes mellitus and cancer research. Infect Immun, 1978 Sep, 21(3), 866 - 73 Surface proteins of typhus and spotted fever group rickettsiae; Osterman JV et al.; Six proteins, previously established as major constituents of intact organisms, were identified in cell envelopes obtained from intrinsically radiolabeled Rickettsia prowazekii . Extrinsic radioiodination of intact organisms conducted at 0.5 micronM iodide indicated that protein 4 was the most peripheral, although protein 1 also had reactive groups exposed on the surface of the organisms . A 10-fold increase in iodide concentration resulted in labeling of protein 2, and at 50 micronM iodide, all six major proteins were radiolabeled . Similar selective labeling was not achieved with R . conorii . Analysis of both typhus and spotted fever group organisms radiolabeled with galactose suggested that carbohydrate was associated with proteins 1, 3, and 4 . Typhus soluble antigen included all major proteins except protein 2, which remained attached to particulate rickettsiae after ether extraction . Protein 4 appeared to be prominent in the surface topography of R . prowazekii, was a component of soluble antigen and may have an important role in rickettsiae-host interactions. Zh Mikrobiol Epidemiol Immunobiol, 1978 Aug, (8), 30 - 5 {Preventive effect of several antibiotics in experimental rickettsial infections}; Klimchuk ND; Dibiomycin, biomycin, and biomycin in combination with erythromycin (antibiotics with a wide range of action) used once or in interrupted courses produced a distinct prophylactic effect in experimental rickettsia infection in guinea pigs . The most pronounced prophylactic action was observed when chemoprophylaxis was combined with immunization with inactivated typhud vaccine . Formation of typhus immunity was seen when such chemoprophylaxis scheme was followed. Infect Immun, 1978 Aug, 21(2), 417 - 24 Mechanisms of immunity in typhus infection: some characteristics of Rickettsia mooseri infection of guinea pigs; Murphy JR et al.; Rickettsia mooseri infection has been studied in syngeneic guinea pigs inoculated intradermally with the objective of developing a model for the study of immune mechanisms . Characterization of infection included the following: a study of replication, dissemination, and clearance of rickettsiae; measurement of the antibody response with different rickettsial antigens and tests; and attempts to measure the cell-mediated immune response using the correlate of delayed-type hypersensitivity skin reactions . Following intradermal inoculation, rickettsiae replicate locally and then spread to the draining lymph nodes and subsequently cause systemic infection . Spread to draining lymph nodes occurred before the appearance of circulating antibody, whereas systemic infection occurred afterwards . Two distinct patterns of acquired resistance developed . The first was marked by a cessation of rickettsial growth within a given organ and the second by a clearance of rickettsiae . The duration of each of these phases differed markedly from one organ to another . Delayed-type hypersensitivity was not demonstrated by skin testing. Am J Epidemiol, 1978 Jul, 108(1), 53 - 9 Antigenic relationships between the typhus and spotted fever groups of rickettsiae; Ormsbee R et al.; Paired sera from cases of epidemic typhus in Ethiopia and from probable cases of Rocky Mountain spotted fever (RMSF) in the United States were examined by microagglutination (MA) and microimmunofluorescence (micro-IF) tests for antibodies against Rickettsia prowazekii, Rickettsia typhi, Rickettsia canada, Rickettsia rickettsii, Rickettsia conorii and Ricksettsia akari . IgG and IgM antibodies against the various rickettsiae were titrated with specific fluorescein-conjugated anti-IgG and anti-IgM sera . Purified, particulate rickettsial antigens were employed in all tests . A majority of patients acutely ill with epidemic typhus produced both IgG and IgM antibodies against R . prowazekii, R . typhi and R . canada . Concurrently they produced IgG (but seldom IgM) antibodies against members of the spotted fever group . In contrast, patients ill with probably spotted fever, while producing IgG and IgM antibodies against R . rickettsii, R . conorii and R . akari, also produced both IgG and IgM antibodies with about equal frequency against members of the typhus group . It was concluded that a relatively broad antigenic relationship exists between rickettsiae of the typhus and spotted fever groups. Practitioner, 1978 Jun, 220(1320), 921 - 6 Immunization for overseas travel; Turner AC; PIP: The latest recommendations for immunization for overseas travel by British nationals as of June 1978 are summarized . Immunizations are divided into 2 groups, 1) those required by International Health Regulations, and 2) those medically recommended . The WHO requires vaccination for smallpox, cholera and yellow fever, recorded on official WHO forms . Yellow fever vaccinations are good for 10 years, and are only given at special locations . Live viral vaccines (smallpox, yellow fever and polio) should be given 3 weeks apart if possible . Contraindications against receiving these vaccines are listed, along with alternate procedures in such cases . Vaccines in the medically recommended group include typhoid-paratyphoid, tetanus, poliomyelitis, plague, typhus and immunoglobulin for infective hepatitis . A polyvalent vaccine for typhoid, paratyphoid A and B, and tetanus is available . The effectiveness of paratyphoid B vaccine is in dispute, and reactions are troublesome . Tetanus and polio immunizations are a must . Plague and typhus shots often produce reactions, and the immunity is not always good, but injections are highly recommended for those travelling in the interior of affected areas . Rabies vaccination is not recommended unless the traveller is to work as a veterinarian . Measles and BCG are suggested for children who are going to live in endemic areas . Zh Mikrobiol Epidemiol Immunobiol, 1978 Jun, (6), 26 - 31 {The effect of various antibiotics on the formation of typhus antibodies following immunization with typhus vaccine}; Klimchuk ND; It was shown that administration in the course of one week, before or after a single use of killed or chemical typhoid vaccine of dibiomycin, biomycin, or biomycin in combination with erythromycin in comparatively high doses produced no negative effect of the production of typhus antibodies and the intensity of antitoxic immunity in albino mice . The same antibiotics failed to influence the antibody formation in guinea pigs if they produced no toxic effect on the animals; but in case of development of toxic phenomena connected with the administration of the mentioned antibiotics a strong depression of antibody production was observed in guinea pigs. Acta Trop, 1978 Jun, 35(2), 101 - 11 {Seroepidemiological investigations in domestic ruminants from Egypt, Somalia and Jordan for the demonstration of complement fixing antibodies against Rickettsia and Chlamydia (author's transl)}; Schmatz HD et al.; 1450 random serum samples of domestic ruminants from Egypt, Somalia and Jordan were investigated for complement fixing antibodies against Rickettsia and Chlamydia . Between 1.5 and 3.4% of the samples from the animals investigated had antibodies against the RMSF-group of Rickettsia, with exception of the sera from Somalian cattle and sheep from Jordan . Antibodies against Rickettsia of the Typhus-group were found in 4 cattle and 1 goat from Jordan and 2 sheep from Egypt; by agglutination test with type-specific antigen they were identified as antibodies against R . typhi . Using 2 different antigens, antibodies against Coxiella burnetii were found in every population tested . The prevalence was 2.0 to 12.2%, with the exception of cattle in Somalia, where only 1 positive serum (0.2%) was found . 27% of the serum samples from Jordan and 22% from Egypt but none of the 802 samples from Somalia had antibodies against Chlamydia . The results are discussed under an epidemiological point of view. J Infect Dis, 1978 May, 137(5), 578 - 82 Enzyme immunoassay of antibody to Rochalimaea quintana: diagnosis of trench fever and serologic cross-reactions among other rickettsiae; Hollingdale MR et al.; Enzyme immunoassay (EIA) tests were used to diagnose trench fever and to determine cross-reactions of Rochalimaea quintana with other rickettsiae . The results were compared with those obtained by counterimmunoelectrophoresis (CIE) . All sera from cases of primary or relapsed forms of trench fever were positive both in EIA, with serum antibody titers of 1:20-1:640, and in CIE, giving one to three precipitin lines . Sera from patients with other rickettsial infections were also tested for reactivity with R . quintana antigen: typhus group (Rickettsia prowazekii, Ricketsia mooseri), 15 sera; spotted fever group (Ricketsia ricketsii, Rickettsia akari), eight sera; and scrub typhus (Rickettsia tsutsugamushi), six sera . Strong reactions occurred with four sera from patients with scrub typhus, giving one or two lines in CIE and EIA titers of 1:40-1:160; these results were extended to guinea pig antisera to R . tsutsugamushi . About 50% of typhus group sera reacted with a single line in CIE and had antibody titers of 1:20-1:80 by EIA . The results show that EIA is accurate for the diagnosis of trench fever and, with the results obtained by CIE, suggest that R . quintana is antigenically related to R . tsutsugamushi and possibly to rickettsiae in the typhus group as well. Zh Mikrobiol Epidemiol Immunobiol, 1978 May, (5), 83 - 6 {Study data on ornithosis infection in the Azerbaijan SSR}; Abushev FA; Data are presented on the study of epizootology and epidemiology of ornithosis . There were revealed natural foci of ornithosis in the Kyzyl-Agach preserve, at the Sary-Su lakes and at the Glinyany island; these foci were dihostal and polyhostal, as well as conjointed (ornithosis, arboviruses, Q-fever, Asian tick-borne typhus, leptospirosis) . Anthropurgic foci were found in 12 populated localities, semi-wild dove serving as the main component . Fowl was found to be infected in 12 poultry-farms; occupational ornithosis was present among the bird-rearers . Immunological structure of the population in respect to ornithosis was studied . Patients with various diagnoses showed positive serological reactions retrospectively; there were 155 cases of ornithosis among them. Physiologie, 1978 Apr-Jun, 15(2), 91 - 5 The effect of prolonged dextran administration in guinea pigs; Schneider FR et al.; Dextran 70 6% in 0.9% NaCl solution, injected intraperitoneally in guinea pigs, 10 ml/kg b.w./day, during a period of 27 days brought the lowering of the plasma proteins level, whie the total colloid osmostic pressure (due to Dectran and proteins) remained close to that of the control group . The concentration of typhus 0 antibodies and the number of precipitation lines assayed during immunodiffusion in gel were lower than in thd control group . The diminishing of the red blood cells number and of the amount of hemoglobin corresponds to the decreasing proportion of the erythroblastic series (in the bone marrow) . Histological changes in the liver and in the kidney are minimal and could be explained by the effort made by these depurating organs to eliminate Dextran from the body. Am J Trop Med Hyg, 1978 Mar, 27(2 Pt 1), 339 - 49 Epizootiology of epidemic typhus (Rickettsia prowazekii) in flying squirrels; Sonenshine DE et al.; Vector transmission of Rickettsia prowazekii among wild flying squirrels, Glaucomys volans, was suggested by the occurrence of natural infection of squirrel lice and fleas . Lice, mostly Neohaematopinus sciuropteri Osburn, were found infected in the fall in each of 2 consecutive years; 4 of the 8 pools of this insect tested were infected . Fleas, Orchopeas howardii (Baker), were found infected on two occasions in 1 of the 2 consecutive years . However, only 2 of 14 flea pools were infected . No evidence of infection was found in mites, Haemogamasus reidi Ewing and Androlaelaps fahrenholzi (Berlese) . These findings implicate the flying squirrel louse and flea as possible vectors in nature . Serologic tests of flying squirrel sera revealed a maximum incidence of seroconversions in the fall and early winter months, coincident with the maximum increase in abundance of the suspected arthropod vectors . The infection was found to persist form year to year in the same enzootic foci . Infection appeared to spread most rapidly in young, non-immune animals born in the preceding spring and summer after congregating in dense aggregations in the fall . No other animals in the same habitat were found to have been infected . Aspects of the ecology of the ectoparasites associated with the flying squirrels are described, especially seasonal activity and abundance in nests . The potential public health importance of this sylvan disease in flying squirrels and in its ectoparasites, particularly the non-host specific, wide ranging squirrel flea, is noted. Infect Immun, 1978 Mar, 19(3), 1068 - 75 Experimental infection of mouse peritoneal mesothelium with scrub typhus rickettsiae: an ultrastructural study; Ewing EP Jr et al.; The infection cycle of Rickettsia tsutsugamushi in mouse peritoneal mesothelial cells, observed late in the course of an established infection, intimately involved the host cell plasma membrane . Organisms multiplied in the cytoplasm, moved to the cell periphery, and acquired a host-membrane coat as they budded from the cell surface . Rickettsiae enveloped by this membrane entered other mesothelial cells, apparently by a phagocytic mechanism . Organisms escaped from the phagocytic vacuole as the vacuole membrane and host membrane coat disintegrated . Free rickettsiae replicated by binary fission in the cell cytoplasm . Rickettsial infection of mesothelial cells induced conspicuous cellular hypertrophy with increased numbers of unaltered cytoplasmic organelles. Trans R Soc Trop Med Hyg, 1978, 72(4), 412 - 6 Single dose doxycycline therapy for scrub typhus; Brown GW et al.; A single dose of 200 mg of doxycycline was shown to be as effective as a seven day course of tetracycline, in patients suspected of having scrub typhus . 65 (44%) of the 149 patients studied fulfilled the criteria for definite diagnosis of scrub typhus; 10 had an additional diagnosis . Rickettsia tsutsugamushi was isolated from 49 (75%) patients . There was no difference between the two treatment groups in time to defervescence, abolition of cough and headache, or in the time taken to recover well-being . There were no relapses in either group . Of the remaining 84 patients, a causal diagnosis was achieved in 52 . Irrespective of a diagnosis there was no difference in apparent response to either doxycycline or tetracycline. Pavlov J Biol Sci, 1978 Jan-Mar, 13(1), 42 - 54 A preliminary study in medical anthropology in Brunei, Borneo; Wolf S et al.; Nine rural village communities in the jungle of Brunei, Borneo were studied to ascertain possible effects of rapid social change on the health of the inhabitants . The social mores and religious beliefs of the rural tribes--Iban, Dusun, and Punan--have undergone but little change over many hundreds of years . During the past three decades, however, enormous social pressures for change have envolved from extraordinary economic prosperity of the region, due to the exploitation of large discoveries of oil and gas . Much of the money has been invested in health care, with the result that malaria, typhus and other tropical scourges have been virtually wiped out . Child and maternal mortality have been reduced to the standards of some of the healthiest countries in the world . The young of the formerly illiterate population are being rapidly educated in new schools scattered throughout the nation . New roads are penetrating the jungle and a thriving lumber industry has been established . Motor boats for the rivers, T.V . and even a national airline have been added . Despite these incursions a vigorous proseletizing by the Moslem and to a lesser extent by the Christian church, the villagers have held tenaciously to their ancient animistic beliefs . Living in long houses, they have also been able to maintain a tightly cohesive patriarchal family structure . Against this background there is as yet little or no evidence of the major diseases of Western society--coronary artery disease and hypertension, although most forms of cancer are commonly encountered . Brunei offers a splendid opportunity to test the putative relationship of chronic vascular disease to social structure and a way of life . Future studies may be made prospectively as the almost inevitable breakdown of old customs and patterns of living occurs in the face of rapid modernization. J Hyg Epidemiol Microbiol Immunol, 1978, 22(3), 306 - 11 Sero-epidemiological survey of scrub typhus; Menon RD et al.; A total of 1017 human sera from ecologically different areas in the states of Rajasthan and Jammu & Kashmir were subjected to the CF test using the Gilliam strain antigen of R . tsutsugamushi . Results revealed that 2.4% and 3.5% of the populations examined in the two states respectively, were found to possess antibodies to the test antigen . The titres of positive sera varied from 1:8 to 1:32 . Findings of this survey could be correlated with the local topography, presence or absence of vector and the exposure of susceptible population to the rickettsial agent . However, the presence of hidden foci in the neighbouring areas not covered by the current survey cannot be ruled out. J Clin Microbiol, 1977 Dec, 6(6), 639 - 41 Improved chicken embryo cell culture plaque assay for scrub typhus rickettsiae; Woodman DR et al.; The plaque technique for three strains of Rickettsia tsutsugamushi in chicken embryo cell cultures was greatly improved by modifying the trypsinizing procedure and employing homologous chicken serum in the overlay medium. J Infect Dis, 1977 Dec, 136(6), 813 - 21 Typhus fever: report of an epidemic in New York City in 1847; Gelston AL et al.; An epidemic of thyphus fever in New York City in 1847 that was associated with massive immigrations from Ireland is described by review of the records of 138 cases admitted to The New York Hospital during a seven-week period . Medical understanding of epidemic diseases, of typhus, and of therapeutics is examined . Most patients (80%) acquired the disease during passage, but 20% of the cases resulted from secondary spread in New York . The illness was characterized by high fever, headache, myalgias, and loss of appetite . Complications, most commonly central nervous system dysfunction and secondary bacterial infections, occurred in 29% of the cases . The mortality rate was 11% . Therapy was directed at cleansing the bowel and diaphoresis . Bleeding was not employed . In spite of mistaken concepts about epidemic diseases, measures were employed that controlled spread of the disease. Southeast Asian J Trop Med Public Health, 1977 Dec, 8(4), 503 - 9 Electrocardiographic changes in scrub typhus patients; Fang CY et al.; Ninety-eight cases of scrub typhus were examined electrocardiographically . Various findings beyond the normal range were as follows: In the febrile stage, sinus arrhythmia with some beats below 60 per minute, flat or low T waves in the left precordial leads, sinus tachycardia, ST segment elevation of 4-l mm in V2, prominent u waves measuring 1 mm or more in amplitude, tall and peaked T waves in V2-4, incomplete right bundle branch block, T wave inversion in V3-4, first degree A-V block, Q-Tc interval prolongation, notched T waves in V3, AV junctional escapes, prominent Ta waves or depression of PR segments in V2, and right axis deviation; in the convalescent stage, sinus arrhythmia with some beats below 60 per minute, prominent u waves measuring 1 mm or more in amplitude, tall and peaked T waves in V2-4, flat or low T waves in the left precordial leads, incomplete right bundle branch block, sinus tachycardia, first degree A-V block, Q-Tc interval prolongation, T wave inversion in V3-4, ST segment elevation of 4 mm in amplitude in V2, ventricular premature contractions, atrial premature contractions, and right axis deviation . In comparison with the electrocardiographic findings in 101 asymptomatic normal subjects, flat T waves in the precordial leads, tall and peaked T waves in V2-4 in both acute and convalescent stages, and sinus arrhythmia with some beats below 60 per minute in the convalescent stage were more frequent in cases . Electrocardiographic abnormalities were present most commonly in the acute illness, and our findings support the impression that, with few exceptions, prompt treatment of scrub typhus with antibiotics prevents the serious cardiac complications seen prior to the antibiotic era. Infect Immun, 1977 Nov, 18(2), 324 - 9 Host defenses in experimental scrub typhus: effect of chloramphenicol; Shirai A et al.; The effect of chloramphenicol treatment on the development of immunity to scrub typhus in mice was studied . Chemotherapy was administered either shortly before infection and for 14 days thereafter (group I), or from 7 to 21 days postinfection (group II) . Although the full course of either regimen resulted in complete protection of the mice against subsequent challenge with the homologous strain of Rickettsia tsutsugamushi, initiation of chemotherapy at 7 days postinfection resulted in more rapid development of immunity against both the original infection and subsequent challenge . In both treatment groups, a 1- to 2- day hiatus was observed between immunity to challenge in the treated animal and the ability to transfer this immunity to syngeneic recipients with lymphocyte-enriched spleen cells . Similarly, complement-fixing antibodies were not detectable until shortly after the animals were able to resist challenge . These data supported the conclusion that the rickettsiostatic effect of chloramphenicol allows the infected animal time to mount an effective immune response and, further, that initiation of chemotherapy early in the infection may delay development of this response. Acta Virol, 1977 Sep, 21(5), 439 - 41 Some biological properties of an endotoxic lipopolysaccharide from the typhus group rickettsiae; Schramek S et al.; A lipophilic thermostable lipopolysaccharide (LPS) complex was isolated by phenol extraction from purified suspensions of the typhus group rickettsiae . The LPS complex is antigenic and possesses some endotoxic properties such as toxicity for actinomycin D-treated mice, pyrogenicity for rabbits and guinea pigs, ability to elicit hypothermia in white rats and local Schwartzman reaction and active cutaneous anaphylaxis in rabbits. Am J Epidemiol, 1977 Aug, 106(2), 172 - 5 Rickettsia tsutsugamushi infection and scrub typhus incidence among Chinese military personnel in the Pescadores Islands; Olson JG et al.; Personnel assigned to infantry units of the army of the Republic of China (Taiwan) stationed in the Pescadores Islands experienced the highest incidence rate of scrub typhus (4%) and the highest rate of Rickettsia tsutsugamushi infection (12%) of the units studied during 1976 . The ratio of scrub typhus to infection with R . tsutsugamushi was 30% . Non-immune personnel, when infected, were more likely to develop scrub typhus than were those who had previously been infected . There was a correlation between clinical illness and high antibody titers developed in response to the infection. Immun Infekt, 1977 Aug, 5(4), 163 - 6 {Seroepidemiological investigations on the prevalence of rickettsial antibodies in man in the Federal Republic of Germany (author's transl)}; Schmatz HD et al.; 1,600 random serum samples from inhabitants of Hesse were investigated for rickettsial antibodies by complement fixation test . Antibodies were found in 19 samples (1,2%) against RMSF-group antigen with titers between 1:10 and 1:640 . These results confirm recent reports on natural foci of such rickettsial infections in the Federal Republic of Germany . Antibodies against rickettsia of the Typhus-group or Coxiella burnetii could not be detected by the complement fixation reaction . None of the sera reacted with significant titer in the Weil-Felix-Test. Am J Trop Med Hyg, 1977 Jul, 26(4), 743 - 7 Mycoplasma pneumonia: a study on hospitalized American patients with pneumonia in Vietnam; Arnold K et al.; A prospective study on consecutively hospitalized pneumonia patients showed that 41.5% of 58 patients had a fourfold rise in the complement-fixation titer for Mycoplasma pneumoniae . Viral isolation techniques and serologic tests for influenza A1, A2 and B, parainfluenza 1 and 3, respiratory syncytial virus and the adeno virus group yielded only a single positive isolate for influenza A2 . Serologic tests for melioidosis, leptospirosis, scrub, murine and epidemic typhus and psittacosis were all negative . The clinical manifestations were not distinctive for the positive M . pneumoniae patients when compared with the patients having a negative M . pneumoniae complement-fixation test . The symptoms and signs and laboratory and radiologic findings were similar to those described in other reports on primary atypical pneumonia. J Clin Microbiol, 1977 Jul, 6(1), 76 - 80 Plaque assay and cloning of scrub typhus rickettsiae in irradiated L-929 cells; Oaks SC Jr et al.; It was demonstrated that gamma-irradiated L-929 cells support plaque formation by three strains of Rickettsia tsutsugamushi and representative species of the spotted fever and typhus group rickettsiae . Sensitivity of the plaque assay for detection of viable scrub typhus rickettsiae was similar to that achieved with intraperitoneal inoculation of random-bred mice . The concentration of irradiated cells and the temperature and length of incubation were all found to affect plaque size . A technique combining terminal dilution and plaque purification was used to obtain clones of three strains of scrub typhus rickettsiae. Southeast Asian J Trop Med Public Health, 1977 Jun, 8(2), 232 - 5 Presence of antibodies to scrub typhus and murine typhus in dogs from Selangor, Peninsular, Malaysia; Huxsoll DL et al.; Dog sera, collected from different communities throughout Selangor, Peninsular Malaysia, were investigated for the presence of antibodies to R . tsutsugamushi and R . typhi . Scrub typhus antibodies were present in animals from the rural areas only, whereas murine typhus antibodies were observed in equal numbers of dogs from both rural and metropolitan areas . Greater percentage of dogs from suburban areas had demonstrable antibody titers to murine typhus than from the urban area. Southeast Asian J Trop Med Public Health, 1977 Jun, 8(2), 200 - 6 Chigger (Acarina:Trombiculidae) surveys of the west coast beaches of Sabah and Sarawak; Dohany AL et al.; Leptotrombidium (Leptotrombidium) arenicola Traub, a vector of scrub typhus, had previously been found to occur in the coastal vegetation behind the edge of open sand along the beaches of Peninsular Malaysia . Surveys of the west coast beaches of Sabah and Sarawak were conducted to determine if this species occurs in similar habitat in East Malaysia on the island of Borneo . Leptotrombidium (L.) arenicola was not collected from the eighteen sites studied . Of the 11,982 mite larvae collected, 55 per cent were L.(L.) deliense (Walch), a well-known, widespread vector of scrub typhus. Southeast Asian J Trop Med Public Health, 1977 Mar, 8(1), 99 - 103 Murine typhus in a Malaysian village; Brown GW et al.; A high prevalence of murine typhus was found in the human and rodent populations of Senaling, West Malaysia . In addition to 2 index cases which prompted the investigation, 45% of the humans and 35% of the rodents had IFA titers of 1/50 or greater . Serological studies provided evidence of recent infections in 3 human subjects . In a control group of Malaysian soldiers IFA titers of 1/50 or greater were found in only 13 (5%) of 265 sera tested. Infect Immun, 1977 Mar, 15(3), 813 - 6 Indirect immunofluorescence antibodies in natural and acquired Rickettsia tsutsugamushi infections of Philippine rodents; Van Peenen PF et al.; Antibodies against Rickettsia tsutsugamushi detected by the indirect fluorescent-antibody test (IFAT) were present in most rats trapped from a human focus of scrub typhus in the Philippines . Rickettsiae were isolated only from rats with positive IFATs . Naturally acquired antibodies persisted for at least 11 months, and antibodies resulting from experimental infections of rats persisted for at least 7 months . A common Philippine rodent, Rattus mindanensis, tolerated experimental infections with both local and standard Karp strains of R . tsutsugamushi, and such infections always produced a positive IFAT. Am J Epidemiol, 1977 Mar, 105(3), 261 - 71 Serologic diagnosis of epidemic typhus fever; Ormsbee R et al.; Microagglutination (MA), microcomplement-fixation (CF), indirect microimmunofluorescence (micro-IF) and Weil-Felix (WF) tests were compared for sensitivity and specificity in detection of antibodies against Rickettsia prowazekii and for serologic diagnosis of epidemic typhus fever . Paired sera from hospitalized Ethiopian patients suffering from febrile illness were examined . Purified particulate rickettsial antigens used in MA, CF and micro-IF tests were made from infected yolk sacs by differential centrifugation from molar NaCl and from NaCl-sucrose, D20=1.1491, pH 5.5 . In sensitivity the tests ranked micro-IF greater than MA greater than CF greater than WF . Use of specific anti-IgG and anti-IgM sera in parallel micro-IF tests made it possible to differentiate cases of recrudescent epidemic typhus (Brill-Zinsser disease) from primary epidemic typhus cases . Antibodies reacting in high titer with R . canada were produced by 86% of patients with rising antibody titers against R . prowazekii. Infection, 1977, 5(2), 82 - 4 Murine typhus and spotted fever in Israel in the seventies; Rosenthal T et al.; One hundred and eleven cases of rickettsial disease-100 cases of murine typhus and 11 cases spotted fever--seen over a four year period at the Chaim Sheba Medical Center are reviewed . The clinical picture of murine typhus (caused by Rickettsia mooseri and transmitted by Xenopsylla cheopis) could not be distinguished from that of spotted fever (caused by a Rickettsia similar to Rickettsia conori and transmitted by Rhipicephalus) . Some quite severe cases of murine typhus and some relatively mild cases of spotted fever were seen. Infection, 1977, 5(2), 76 - 81 {Brill's Disease in Eastern Slovakia (author's transl)}; Mittermayer T; A report is presented on the epidemiological, clinical and serological findings obtained in 37 patients in the southern part of Eastern Slovakia who were diagnosed as having Brill's disease . All patients presented with a recurrence of classical louse-borne typhus; in no case did the disease occur for the first time . It is recommended that all patients with a febrile illness of uncertain aetiology be subjected to a routine serological examination for louse-borne typhus in epidemic areas . Careful supervision is necessary since if such late recurrences are not detected they can result in a renewed spread of the disease in an environment where lice prevail . This was demonstrated in one of the patients in this study. Arch Invest Med (Mex), 1977, 8(1), 1 - 4 Surface fixation as a rapid test for diagnosis of toxoplasmosis; Ruiz-Castaneda M; Surface fixation is a rapid and simple method for the detection of antigen-antibody reactions . It has been used as an epidemiologic and diagnostic criterium for brucellosis, typhus and typhoid fever and recently found to be an encouraging test for amebiasis . Data concerning its application in toxoplasmosis has been considered a justified addition to the more complicated procedures used for the diagnosis of this infection, which has become a world-wide problem . It may thus be used as a screening test, as well as a simplified method of titration of postive sera. Trans R Soc Trop Med Hyg, 1977, 71(4), 297 - 9 Antibodies against murine typhyus in sera from Indonesians; Van Peenen PF et al.; A sero-epidemiological study of human CF and indirect immunofluorescence antibodies against murine typhus was conducted in Indonesia . Antibody prevalences ranged from 10% to 20% in sera of Indonesians from Java and Sumatra to less than 2% in sera from islands east of Java. Trans R Soc Trop Med Hyg, 1977, 71(6), 493 - 7 Scrub typhus infection in rats in four habitats in Peninsular Malaysia; Muul I et al.; Rickettsia tsutsugamushi isolations were attempted from blood samples obtained from rats captured in four adjacent habitats near Kuala Lumpur, Malaysia . Antibody surveys were also made . Rickettsial infections were most frequent in rats captured in the forest and in lalang grass (Imperata cylindrica) and least frequent in the most extensively disturbed habitat, an Orang Asli (aborigine) village . Forest rats such as Rattus sabanus (31%), as well as rats in the subgenus R . (Rattus), i.e . R . tiomanicus (26%) and R . argentiventer (35%) had frequent active infections . The house rat R . exulans had less frequent infections (15%) . Frequency of antibody occurrence followed a similar pattern . No marked seasonal differences in the frequency of infections could be detected during the 18-month study. Trans R Soc Trop Med Hyg, 1977, 71(4), 338 - 42 Epidemiological and serological study of scrub typhus among Chinese military in the Pescadores islands of Taiwan; Bourgeois AL et al.; An outbreak of 69 cases of scrub typhus occurred among Chinese military personnel stationed in the Pescadores Islands, Taiwan Province, Republic of China between May and November 1975 . A retrospective epidemiological study of this outbreak indicated that military personnel over 40 were more likely to have scrub typhus than those under 40 . High risk groups included the Garrison Force (home guard), anti-aircraft gunners and infantry and armoured units stationed at Hsing-jen . The onset of symptoms in 69% occurred within one year of residence in the Pescadores . The clinical course of scrub typhus and the serological response to infection were also studied . Eschar formation, fever, headache chills and lymph node enlargement were the predominant clinical manifestations noted . The indirect immunofluorescent antibody test (IFAT) demonstrated diagnostic (four-fold) rises in antibody titres to Rickettsia tsutsugamushi reference strains in 36 of 41 paired sera tested . 11 of 19 patients from whom only single sera were obtained had IFA titres presumptive of scrub typhus (greater than or equal to 1:160) . Of 19 patients experiencing possible primary infections, 13 (68%) responded with antibodies directed against more than one reference strain of R . tsutsugamushi . These results suggest that several antigenically diverse strains of R . tsutsugamushi may be active in the Pescadores. Trans R Soc Trop Med Hyg, 1977, 70(5-6), 444 - 8 Scrub typhus: a common cause of illness in indigenous populations; Brown GW et al.; An explanation was sought for the disparity between the low reported incidence of scrub typhus and the high prevalence of antibody to Rickettsia tsutsugamushi in the rural population of Malaysia . A combination of isolation of the organism, titration of antibody by indirect immunofluorescence, and the Weil-Felix test was used to confirm infections . Scrub typhus was found to be very common, causing 23% of all febrile illnesses at one hospital . The infection was particularly prevalent in oil-palm workers, causing an estimated 400 cases annually in a population of 10,000 people living on one plantation . The clinical syndrome, whether mild or severe, was difficult to distinguish from that due to other infections . Eschars, rashes and adenopathy were uncommon . When used to examine early sera, the Weil-Felix test failed to confirm the diagnosis in most infections.20 J Clin Microbiol, 1977 Jan, 5(1), 39 - 41 Failure of cyclophosphamide to significantly enhance isolation of Rickettsia tsutsugamushi from wild Philippine rats; van Peenen PF et al.; Treatment of wild rats from a known scrub typhus focus in the Philippines with cyclophosphamide did not significantly enhance the isolation rate of Rickettsia tsutsugamushi using mouse inoculation techniques . Similarly, cyclophosphamide treatment of mice inoculated with organs of wild rats did not increase the recovery of rickettsiae, and isolation of rickettsiae was about equal from biopsies obtained before and after immunosuppression of wild rats. Infect Immun, 1977 Jan, 15(1), 124 - 31 Experimental scrub typhus immunogens: gamma-irradiated and formalinized rickettsiae; Eisenberg GH Jr et al.; Scrub typhus immunogens were prepared by exposing infected yolk sac suspensions of Rickettsia tsutsugamushi to various doses of gamma radiation . Mouse lethality was abolished at doses greater than 200 krads, whereas immunogenicity of the suspensions, as shown by mouse protection tests, was diminished relatively little by radiation doses in the 200- to 400-krad range . Using a 300-krad gamma dose to provide a safety factor, immunogens were prepared and their protective capacity was contrasted with formalinized scrub typhus immunogens prepared by conventional techniques . Formalinized suspensions afforded mice only partial protection against intraperitoneal challenge with 1,000 50% mouse lethal doses of the virulent homologous strain and no significant protection against similar challenge with an equally virulent heterologous strain . Using the same strains, radiation-inactivated preparations provided 100% protection against 10,000 50% mouse lethal doses of the homologous strain and 70% protection against challenge with the same doses of a heterologous strain . Neither immunogen was a potent stimulator of antibody production as measured by the complement-fixation test . Cell-transfer studies using inbred mice indicated a role for cell-mediated immunity after vaccination with gamma-irradiated immunogens, but no cell-mediated protection could be demonstrated after vaccination with formalin-inactivated rickettsiae. Infect Immun, 1977 Jan, 15(1), 280 - 6 Characterization of the Madrid E strain of Rickettsia prowazekii purified by renografin density gradient centrifugation; Dasch GA et al.; The avirulent Madrid E strain of Rickettsia prowazekii cultivated in chicken yolk sacs could be purified successfully with a Renografin density gradient method developed previously for Rickettsia typhi . Recovery during purification, viability, and lack of contamination with host cell components were similar for the two species, although yields of R . prowazekii per yolk sac were lower . Purified typhus rickettsiae provided satisfactory antigens in the complement fixation, Ouchterlony double-diffusion, and microagglutination tests . The retention of the typhus soluble group antigen during purification was readily demonstrated by complement fixation tests . However, removal of the soluble group antigen by ether treatment was not always adequate for the demonstration of type-specific particulate antigens . Heat-killed R . prowazekii cells gave higher serum microagglutination titers than untreated or formalized cells, a difference was noted for R . typhi cells . Although the protein profiles of whole cells and extracts of R . typhi and R . prowazekii on sodium dodecyl sulfate-polyacrylamide gels were relatively similar, a small but reproducible, difference in the electrophoretic mobilities of their malate dehydrogenases was detected . Purification of typhus rickettsiae on Renografin gradients has no apparent adverse effects on their metabolic or antigenic properties. Trop Geogr Med, 1976 Dec, 28(4), 303 - 8 The prevalence of scrub typhus antibodies in residents of West Malaysia; Robinson DM et al.; Based on the prevalence of antibody, an estimated 3% of the population of rural Malaysia is infected with Rickettsia tsutsugamushi each year, resulting in positive antibody rates in focal areas of 6 to 69% . Most of these infections do not appear to produce clinical scrub typhus . A wide range of seropositivity rates was found in areas otherwise resembling each other in predominant occupation, terrain, and nearby habitat . The prevalence rates however were significantly higher in people who worked in forested areas and significantly lower in people with urban occupations. Infect Immun, 1976 Oct, 14(4), 1071 - 6 Mechanisms of immunity in typhus infections . VI . Differential opsonizing and neutralizing action of human typhus rickettsia-specific cytophilic antibodies in cultures of human macrophages; Beaman L et al.; Human peripheral blood monocytes were incubated in vitro for 6 days to allow time for transformation into macrophage-like cells . Cytophilic antibodies in typhus convalescent human serum were demonstrated by addition of Rickettsia mooseri or Rickettsia prowazeki to passively sensitized human peripheral blood monocyte-derived macrophages that were held at 4 degrees C . Rosettes of rickettsiae were found around macrophages sensitized with immune serum but not around macrophages that had been incubated with normal serum . Inhibition of rosette formation occurred if the macrophages were maintained in normal human serum before addition of immune human serum . Rosettes of R . mooseri were also formed around monocytes obtained from an individual infected with R . mooseri . If the antibody-sensitized macrophages were maintained at 34 degrees C, enhanced phagocytosis of R . mooseri or R . prowazeki occurred as compared with macrophages exposed to normal human serum before infection . However, the cytophilic antibody did not significantly inhibit the subsequent growth of R . prowazeki within the macrophages . This is in contrast to results obtained when R . prowazeki was mixed with immune serum before addition to the macrophage . In the latter case, growth of R . prowazeki was largely inhibited . The significance of antibody cytophilic for macrophages in typhus infections is discussed. Infect Immun, 1976 Oct, 14(4), 1065 - 70 Mechanisms of immunity in typhus infections . V . Demonstration of Rickettsia mooseri-specific antibodies in convalescent mouse and human serum cytophilic for mouse peritoneal macrophages; Beaman L et al.; Antibodies in both mouse and human Rickettsia mooseri (Rickettsia typhi) convalescent serum that were cytophilic for mouse macrophages were demonstrated by the rosette technique . Mouse peritoneal macrophages, passively sensitized with early and late serum from mice with a sublethal infection of R . mooseri, were washed and exposed to rickettsiae . Rosettes of rickettsiae were found around macrophages, maintained at 4 degrees C, which had been sensitized with immune serum (direct sensitization of macrophages), but no rosettes were found around macrophages sensitized with serum from normal mice . When the macrophages were maintained at 34 degrees C after addition of the rickettsiae, phagocytosis of rickettsiae occurred, indicating one probable role for cytophilic antibodies in typhus infections . If the rickettsiae were mixed with serum from infected mice, washed, and then added to macrophages (indirect sensitization of macrophages), more rosettes were found around the macrophages than around directly sensitized macrophages . The presence of mouse immunoglobulin G on the macrophage surface was also shown by staining living sensitized macrophages with rabbit fluroescein-conjugated anti-mouse immunoglobulin G. J Clin Microbiol, 1976 Sep, 4(3), 277 - 83 Recent experience with the complement fixation test in the laboratory diagnosis of rickettsial diseases in the United States; Shepard CC et al.; Sera from patients suspected of having rickettsial infections were tested in the complement fixation test with antigens prepared from the rickettsiae of Rocky Mountain spotted fever (SF), rickettsial pox (RP), murine typhus, epidemic typhus, and from Rickettsia canada (RC) . Eight units of antigen were used in all cases and two units in man . Only those patients with antibody titers of 1:16 or higher were included in the study . Largely on the basis of comparative titers, the patients were divided into two groups: 102 with SF and 35 with infections by one of the members of the typhus group . The antibody titers were higher with SF antigen than RP antigen in 72% of the SF patients, and in only two SF patients was the RP titer higher, and then by only one tube (twofold dilution) . There seemed little advantage in including the RP antigen in the battery of rickettsial antigens . Cross-reaction with at least one of the typhus antigens was observed in the sera from 64% of the SF patients . It was extensive enough to be confusing (within one tube) in 17% with eight units of antigen, but the differentiation was more distinct with two units of antigen . The cross-reaction with typhus antigens was as frequent in children with SF as it was in adults; thus, it is unlikely that these cross-reactions resulted from previous typhus vaccination . The serological differentiation between murine typhus and epidemic typhus was frequently difficult, but the epidemiological background was distinct . Five patients had higher titers to RC antigen, and four of these may possibly have had RC infections. Infect Immun, 1976 Jul, 14(1), 39 - 46 Host defenses in experimental scrub typhus: role of cellular immunity in heterologous protection; Shirai A et al.; The relative contributions of cellular and humoral immunity in scrub typhus infections were studied in inbred mice employing paired strains of Rickettsia tsutsugamushi differing in virulence . An infectious dose (100 MID50) of the less virulent Gilliam strain resulted in heterologous immune protection against an otherwise lethal challenge (1,000 MLD50) of the virulent Karp strain . Partial heterologous protection against lethal Karp challenge was observed in animals preimmunized with the Gilliam strain as early as 3 days prior to challenge, whereas complete protection against illness and death existed in animals immunized at least 7 days prior to challenge . In the heterologous protection provided by prior Gilliam infection, the role of humoral immunity was not of primary importance for the following reasons: (i) significant levels of complement-fixing antibody against R . tsutsugamushi were not detectable until long after animals were solidly immune; (ii) antibody eventually appearing after Gilliam immunization exhibited a consistently low complement-fixing titer against the immunizing homologous (Gilliam) strain and contained no detectable activity against the heterologous challenge (Karp) strain; and (iii) passive transfer of large quantities of serum from Gilliam