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Emerging Infectious Diseases Jul 2023To elucidate the epidemiology of murine typhus, which is infrequently reported in Japan, we conducted a cross-sectional study involving 2,382 residents of...
To elucidate the epidemiology of murine typhus, which is infrequently reported in Japan, we conducted a cross-sectional study involving 2,382 residents of rickettsiosis-endemic areas in Honshu Island during August-November 2020. Rickettsia typhi seroprevalence rate was higher than that of Orientia tsutsugamushi, indicating that murine typhus is a neglected disease.
Topics: Animals; Mice; Humans; Typhus, Endemic Flea-Borne; Scrub Typhus; Seroepidemiologic Studies; Japan; Cross-Sectional Studies; Orientia tsutsugamushi; Rickettsia typhi
PubMed: 37347821
DOI: 10.3201/eid2907.230037 -
Tropical Medicine and Infectious Disease Mar 2020Flea-borne typhus, due to and , is an infection causing fever, headache, rash, hepatitis, thrombocytopenia, and diverse organ manifestations. Although most cases are... (Review)
Review
Flea-borne typhus, due to and , is an infection causing fever, headache, rash, hepatitis, thrombocytopenia, and diverse organ manifestations. Although most cases are self-limited, 26%-28% have complications and up to one-third require intensive care. Flea-borne typhus was recognized as an illness similar to epidemic typhus, but having a milder course, in the Southeastern United States and TX from 1913 into the 1920s. Kenneth Maxcy of the US Public Health Service (USPHS) first described the illness in detail and proposed a rodent reservoir and an arthropod vector. Other investigators of the USPHS (Eugene Dyer, Adolph Rumreich, Lucius Badger, Elmer Ceder, William Workman, and George Brigham) determined that the brown and black rats were reservoirs and various species of fleas, especially the Oriental rat flea, were the vectors. The disease was recognized as a health concern in the Southern United States in the 1920s and an increasing number of cases were observed in the 1930s and 1940s, with about 42,000 cases reported between 1931-1946. Attempts to control the disease in the 1930s by fumigation and rat proofing and extermination were unsuccessful. The dramatic increase in the number of cases from 1930 through 1944 was due to: the diversification of Southern agriculture away from cotton; the displacement of the smaller black rat by the larger brown rat in many areas; poor housing conditions during the Great Depression and World War II; and shortages of effective rodenticides and insecticides during World War II.
PubMed: 32121541
DOI: 10.3390/tropicalmed5010037 -
The American Journal of Tropical... Jul 2022Murine typhus is an acute undifferentiated febrile illness caused by Rickettsia typhi. In the United States, its reemergence appears to be driven by a shift from the...
Murine typhus is an acute undifferentiated febrile illness caused by Rickettsia typhi. In the United States, its reemergence appears to be driven by a shift from the classic rat-rat flea cycle of transmission to one involving opossums (Didelphis virginiana) and cat fleas. Little is known of the ability of opossums to act as a reservoir and amplifying host for R. typhi. Here, we use Monodelphis domestica (the laboratory opossum) as a surrogate for D. virginiana. Opossums were inoculated via the intraperitoneal (IP) or intradermal (ID) route with 1 × 106 viable R. typhi. Blood and tissues were collected on days 6, 13, 20, and 27 or if moribund. Although one ID-infected opossum died, the remainder did not appear ill, whereas half of the IP-inoculated animals succumbed to infection. Rickettsemia was demonstrated in all animals through week 2 of infection and sporadically in weeks 3 and 4. Rickettsia typhi DNA was detected in all tissues, with most animals demonstrating the presence of bacteria into weeks 3 and 4. Histopathology and immunohistochemistry demonstrated typical findings of rickettsial infection. Akin to infection in rats, the demonstration of disseminated infection, typical inflammation, and prolonged rickettsemia with relatively few clinical effects (especially in the more natural route of ID inoculation) supports the potential of opossums to act as a competent mammalian reservoir and component of the zoonotic maintenance cycle of R. typhi. Understanding the dynamics of infection within opossums may have implications for the prevention and control of murine typhus.
Topics: Animals; Didelphis; Mice; Monodelphis; Rats; Rickettsia; Rickettsia Infections; Rickettsia typhi; Siphonaptera; Typhus, Endemic Flea-Borne
PubMed: 35895366
DOI: 10.4269/ajtmh.21-1076 -
World Journal of Microbiology &... Nov 2015Murine typhus is a zoonosis transmitted by fleas, whose etiological agent is Rickettsia typhi. Rickettsia felis infection can produces similar symptoms. Both are...
Murine typhus is a zoonosis transmitted by fleas, whose etiological agent is Rickettsia typhi. Rickettsia felis infection can produces similar symptoms. Both are intracellular microorganisms. Therefore, their diagnosis is difficult and their infections can be misdiagnosed. Early diagnosis prevents severity and inappropriate treatment regimens. Serology can't be applied during the early stages of infection because it requires seroconversion. Shell-vial (SV) culture assay is a powerful tool to detect Rickettsia. The aim of the study was to optimize SV using a real-time PCR as monitoring method. Moreover, the study analyzes which antibiotics are useful to isolate these microorganisms from fleas avoiding contamination by other bacteria. For the first purpose, SVs were inoculated with each microorganism. They were incubated at different temperatures and monitored by real-time PCR and classical methods (Gimenez staining and indirect immunofluorescence assay). R. typhi grew at all temperatures. R. felis grew at 28 and 32 °C. Real-time PCR was more sensitive than classical methods and it detected microorganisms much earlier. Besides, the assay sensitivity was improved by increasing the number of SV. For the second purpose, microorganisms and fleas were incubated and monitored in different concentrations of antibiotics. Gentamicin, sufamethoxazole, trimethoprim were useful for R. typhi isolation. Gentamicin, streptomycin, penicillin, and amphotericin B were useful for R. felis isolation. Finally, the optimized conditions were used to isolate R. felis from fleas collected at a veterinary clinic. R. felis was isolated at 28 and 32 °C. However, successful establishment of cultures were not possible probably due to sub-optimal conditions of samples.
Topics: Animals; Anti-Bacterial Agents; Chlorocebus aethiops; Early Diagnosis; Real-Time Polymerase Chain Reaction; Rickettsia Infections; Rickettsia felis; Rickettsia typhi; Sensitivity and Specificity; Siphonaptera; Temperature; Typhus, Endemic Flea-Borne; Vero Cells
PubMed: 26289162
DOI: 10.1007/s11274-015-1925-z -
Vector Borne and Zoonotic Diseases... Jun 2018Rickettsia spp. has been detected in dog fleas in Bangkok, Thailand. With the intent of collecting evidence to confirm the presence of rickettsioses in dogs and to...
Rickettsia spp. has been detected in dog fleas in Bangkok, Thailand. With the intent of collecting evidence to confirm the presence of rickettsioses in dogs and to assess the level of associated potential for accidental human infection, human buffy coat from patients with fever of unknown origin (n = 168), whole blood samples from dogs (n = 353), and 19 flea groups from our dog sample population were studied during the 2012 to 2014 study period. The presence of Rickettsia was investigated by molecular detection of 23S rRNA gene of Rickettsia genus, citrate synthase (gltA) gene, and 17-kDa outer membrane gene. All positive samples were confirmed by DNA sequence analysis. Using phylogenetic analysis, three groups of Rickettsia were detected, as follows: Rickettsia felis in 8 patients and 8 dogs; R. felis-like sp. in 2 patients, 5 dogs, and 11 flea samples; and Rickettsia typhi in 3 patients. In addition to confirming the presence of R. felis in Thai patients, the findings of this study suggest that R. felis-like sp. isolated from fleas that were symbiotically coexisting with dogs that we evaluated in this study can transmit and cause disease in dogs and humans in Bangkok.
Topics: Animals; Blood Buffy Coat; Dog Diseases; Dogs; Flea Infestations; Humans; RNA, Bacterial; RNA, Ribosomal, 23S; Rickettsia; Rickettsia Infections; Siphonaptera; Thailand; Zoonoses
PubMed: 29683400
DOI: 10.1089/vbz.2017.2180 -
Medical Microbiology and Immunology Feb 2017Rickettsioses are caused by intracellular bacteria of the family of Rickettsiaceae. Rickettsia (R.) typhi is the causative agent of endemic typhus. The disease occurs... (Comparative Study)
Comparative Study
Rickettsioses are caused by intracellular bacteria of the family of Rickettsiaceae. Rickettsia (R.) typhi is the causative agent of endemic typhus. The disease occurs worldwide and is one of the most prevalent rickettsioses. Rickettsial diseases, however, are generally underdiagnosed which is mainly due to the lack of sensitive and specific methods. In addition, methods for quantitative detection of the bacteria for research purposes are rare. We established two qPCRs for the detection of R. typhi by amplification of the outer membrane protein B (ompB) and parvulin-type PPIase (prsA) genes. Both qPCRs are specific and exclusively recognize R. typhi but no other rickettsiae including the closest relative, R. prowazekii. The prsA-based qPCR revealed to be much more sensitive than the amplification of ompB and provided highly reproducible results in the detection of R. typhi in organs of infected mice. Furthermore, as a nested PCR the prsA qPCR was applicable for the detection of R. typhi in human blood samples. Collectively, the prsA-based qPCR represents a reliable method for the quantitative detection of R. typhi for research purposes and is a promising candidate for differential diagnosis.
Topics: Animals; Bacterial Outer Membrane Proteins; Bacterial Proteins; Blood; Humans; Lipoproteins; Membrane Proteins; Mice, SCID; Molecular Diagnostic Techniques; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Rickettsia typhi; Sensitivity and Specificity; Typhus, Endemic Flea-Borne
PubMed: 27696011
DOI: 10.1007/s00430-016-0480-z -
PloS One 2021Rickettsioses are neglected and emerging potentially fatal febrile diseases that are caused by obligate intracellular bacteria, rickettsiae. Rickettsia (R.) typhi and R....
Rickettsioses are neglected and emerging potentially fatal febrile diseases that are caused by obligate intracellular bacteria, rickettsiae. Rickettsia (R.) typhi and R. prowazekii constitute the typhus group (TG) of rickettsiae and are the causative agents of endemic and epidemic typhus, respectively. We recently generated a monoclonal antibody (BNI52) against R. typhi. Characterization of BNI52 revealed that it specifically recognizes TG rickettsiae but not the members of the spotted fever group (SFG) rickettsiae. We further show that BNI52 binds to protein fragments of ±30 kDa that are exposed on the bacterial surface and also present in the periplasmic space. These protein fragments apparently derive from the cytosolic GroEL protein of R. typhi and are also recognized by antibodies in the sera from patients and infected mice. Furthermore, BNI52 opsonizes the bacteria for the uptake by antigen presenting cells (APC), indicating a contribution of GroEL-specific antibodies to protective immunity. Finally, it is interesting that the GroEL protein belongs to 32 proteins that are differentially downregulated by R. typhi after passage through immunodeficient BALB/c CB17 SCID mice. This could be a hint that the rickettsia GroEL protein may have immunomodulatory properties as shown for the homologous protein from several other bacteria, too. Overall, the results of this study provide evidence that GroEL represents an immunodominant antigen of TG rickettsiae that is recognized by the humoral immune response against these pathogens and that may be interesting as a vaccine candidate. Apart from that, the BNI52 antibody represents a new tool for specific detection of TG rickettsiae in various diagnostic and experimental setups.
Topics: Animals; Antibodies, Bacterial; Antibodies, Monoclonal; Antigens, Bacterial; Cell Line; Chaperonin 60; HEK293 Cells; Humans; Mice, Inbred BALB C; Mice, SCID; Periplasm; Rickettsia Infections; Rickettsia typhi; Xenopus laevis; Mice
PubMed: 34111210
DOI: 10.1371/journal.pone.0253084 -
Infectious Disease Reports Oct 2023Murine typhus is an acute febrile illness caused by , an obligately intracellular Gram-negative coccobacillus. Rats () and their fleas () serve as the reservoir and... (Review)
Review
Murine typhus is an acute febrile illness caused by , an obligately intracellular Gram-negative coccobacillus. Rats () and their fleas () serve as the reservoir and vector of , respectively. Humans become infected when -infected flea feces are rubbed into flea bite wounds or onto mucous membranes. The disease is endemic throughout much of the world, especially in tropical and subtropical seaboard regions where rats are common. Murine typhus is reemerging as an important cause of febrile illness in Texas and Southern California, where an alternate transmission cycle likely involves opossums () and cat fleas (). Although primarily an undifferentiated febrile illness, a range of neurologic manifestations may occur, especially when treatment is delayed. Serology is the mainstay of diagnostic testing, but confirmation usually requires demonstrating seroconversion or a fourfold increase in antibody titer from acute- and convalescent-phase sera (antibodies are seldom detectable in the first week of illness). Thus, early empiric treatment with doxycycline, the drug of choice, is imperative. The purpose of this review is to highlight murine typhus as an important emerging and reemerging infectious disease, review its neurologic manifestations, and discuss areas in need of further study.
PubMed: 37987401
DOI: 10.3390/idr15060063 -
Salud Publica de Mexico 2020To determine the presence of Rickettsia typhi in Rhipicephalus sanguineus s.l. and Amblyomma mixtum in southern Mexico.
OBJECTIVE
To determine the presence of Rickettsia typhi in Rhipicephalus sanguineus s.l. and Amblyomma mixtum in southern Mexico.
MATERIALS AND METHODS
Ticks were collected in humans and domestic animals. The presence of Rickettsia was determined by PCR and sequencing.
RESULTS
10/39 work vials amplified fragments of the gltA, htrA and ompB genes. On 7/10 from Rh. sanguineus s.l. collected from dogs and in 3/10 of A. mixtum collected from horse and human. Sequencing indicated R. typhi in Rh. sanguineus and A. mixtum with 100% homology (LS992663.1) for a region of the htrA gene and 99% (LS992663.1) with the regions of the gltA and OmpB genes. The minimum infection rate (TMI) for R. typhi was 3.88.
CONCLUSIONS
Rhipicephalus sanguineus s.l. and Amblyomma mixtum are naturally infected with R. typhi in Southern Mexico.
Topics: Amblyomma; Animals; Cats; Cattle; Dogs; Horses; Humans; Mexico; Rhipicephalus sanguineus; Rickettsia typhi
PubMed: 32549080
DOI: 10.21149/10160 -
International Angiology : a Journal of... Oct 2017Rickettsia was suggested as a possible etiology of Buerger's disease (BD) in the 1980s but this suggestion was never ruled out or proven. Recently, we found evidence of...
BACKGROUND
Rickettsia was suggested as a possible etiology of Buerger's disease (BD) in the 1980s but this suggestion was never ruled out or proven. Recently, we found evidence of Rickettsia by polymerase chain reaction in 3 out of 25 biopsy samples from the amputated limb of a young man diagnosed with BD. The aim of this paper was to investigate the presence of anti-rickettsial antibodies in the sera of BD patients.
METHODS
To detect the IgG class antibody against Rickettsia rickettsii, which has cross reactions with the spotted fever group (RSFG), and Rickettsia typhi, which has cross reactions with typhus fever group, the sera of patients and controls were diluted to 1:64 and analyzed by indirect micro fluorescence immunoassay (MIF).
RESULTS
The MIF study showed that 26 of the 28 patients were positive for Rickettsia rickettsii antibodies and MIF had the same appearance as the positive control, which was provided with the kit. In all members of the healthy control group, Rickettsia rickettsii was negative and had the appearance of the negative control. Rickettsia typhi was negative for all patients and members of the control group.
CONCLUSIONS
A species of Rickettsia associated with the RSFG, which might not be pathogenic for the entire population, may induce BD in the context of a specific genetic or environmental background. RSFG infection could explain key questions about BD, including its gender and geographical distribution, clinical manifestation, angiography pattern, and pathological findings. Evaluating antibodies against RSFG in BD patients from different countries is now highly recommended.
Topics: Adult; Antibodies, Bacterial; Case-Control Studies; Cross Reactions; Diagnosis, Differential; Fluorescent Antibody Technique, Indirect; Humans; Immunoglobulin G; Iran; Male; Middle Aged; Rickettsia Infections; Rickettsia rickettsii; Thromboangiitis Obliterans
PubMed: 26344511
DOI: 10.23736/S0392-9590.17.03420-4