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Journal of Infection in Developing... Sep 2017Rickettsia sibirica mongolitimonae was recently reported as a common rickettsiosis in France. Current serological evidence suggests the presence of scrub typhus and...
INTRODUCTION
Rickettsia sibirica mongolitimonae was recently reported as a common rickettsiosis in France. Current serological evidence suggests the presence of scrub typhus and spotted fever group rickettsiosis in Sri Lanka. We detected a human case of R. sibirica mongolitimonae in Sri Lanka.
METHODOLOGY
A skin biopsy of the eschar was tested for the presence of Rickettsia spp. using qPCR assay targeting a 109-bp fragment of a hypothetical protein and by PCR amplification and sequencing targeting the ompA gene.
RESULTS
A 30-year-old woman who had just returned from travel to a jungle in Sri Lanka was evaluated as an outpatient for fever. Examination revealed an enlarged axillary lymph node, a maculopapular rash and an eschar at her left flank and a skin biopsy of the eschar was performed. The skin biopsy was positive for the presence of Rickettsia spp. by qPCR and PCR amplification and sequencing targeting the ompA gene revealed R. sibirica mongolitimonae. Immunofluorescence assay on an acute serum sample for spotted fever group rickettsial antigens (Rickettsia conorii conorii, R. sibirica mongolitimonae, Rickettsia felis) and typhus group rickettsiae (Rickettsia typhi) was negative. The patient was treated by oral doxycycline (200 mg/day) for one week.
CONCLUSIONS
R. sibirica mongolitimonae should be considered in the differential diagnosis of patients with suspected rickettsiosis in, or returning from, Sri Lanka.
PubMed: 31085830
DOI: 10.3855/jidc.8743 -
The American Journal of Tropical... Mar 2014The prevalence and identity of Rickettsia and Bartonella in urban rat and flea populations were evaluated in Kisangani, Democratic Republic of the Congo (DRC) by...
The prevalence and identity of Rickettsia and Bartonella in urban rat and flea populations were evaluated in Kisangani, Democratic Republic of the Congo (DRC) by molecular tools. An overall prevalence of 17% Bartonella species and 13% Rickettsia typhi, the agent of murine typhus, was found in the cosmopolitan rat species, Rattus rattus and Rattus norvegicus that were infested by a majority of Xenopsylla cheopis fleas. Bartonella queenslandensis, Bartonella elizabethae, and three Bartonella genotypes were identified by sequencing in rat specimens, mostly in R. rattus. Rickettsia typhi was detected in 72% of X. cheopis pools, the main vector and reservoir of this zoonotic pathogen. Co-infections were observed in rodents, suggesting a common mammalian host shared by R. typhi and Bartonella spp. Thus, both infections are endemic in DRC and the medical staffs need to be aware knowing the high prevalence of impoverished populations or immunocompromised inhabitants in this area.
Topics: Animals; Bartonella; Bartonella Infections; DNA, Bacterial; Democratic Republic of the Congo; Disease Vectors; Flea Infestations; Humans; Insect Vectors; Polymerase Chain Reaction; Prevalence; Rats; Rickettsia Infections; Rickettsia typhi; Siphonaptera; Typhus, Endemic Flea-Borne; Urban Population
PubMed: 24445202
DOI: 10.4269/ajtmh.13-0216 -
Microorganisms Jul 2022Chiggers are vectors of rickettsial pathogenic bacteria, spp., that cause the human disease, scrub typhus, in the Asian-Pacific area and northern Australia (known as...
Chiggers are vectors of rickettsial pathogenic bacteria, spp., that cause the human disease, scrub typhus, in the Asian-Pacific area and northern Australia (known as the Tsutsugamushi Triangle). More recently, reports of scrub typhus in Africa, southern Chile, and the Middle East have reshaped our understanding of the epidemiology of this disease, indicating it has a broad geographical distribution. Despite the growing number of studies and discoveries of chigger-borne human disease outside of the Tsutsugamushi Triangle, rickettsial pathogens in chigger mites in the US are still undetermined. The aim of our study was to investigate possible DNA in chiggers collected from rodents in North Carolina, USA. Of 46 chiggers tested, 47.8% tested positive for amplicons of the 23S-5S gene, 36.9% tested positive for 17 kDa, and 15.2% tested positive for . Nucleotide sequence analyses of the -specific 23S-5S intergenic spacer (IGS), 17 kDa, and gene fragments indicated that the amplicons from these chiggers were closely related to those in , , , and unidentified species. In this study, we provide the first evidence of infection in chiggers collected from rodents within the continental USA. In North Carolina, a US state with the highest annual cases of spotted fever rickettsioses, these results suggest chigger bites could pose a risk to public health, warranting further study.
PubMed: 35889061
DOI: 10.3390/microorganisms10071342 -
The American Journal of Tropical... Dec 2010Fleas collected from rats during a three-year period (2000-2003) in 51 areas of all provinces of Cyprus were tested by molecular analysis to characterize the prevalence...
Fleas collected from rats during a three-year period (2000-2003) in 51 areas of all provinces of Cyprus were tested by molecular analysis to characterize the prevalence and identity of fleaborne rickettsiae. Rickettsia typhi, the causative agent of murine typhus, was detected in Xenopsylla cheopis (4%) and in Leptopsylla segnis (6.6%). Rickettsia felis was detected in X. cheopis (1%). This is the first report of R. typhi in X. cheopis and L. segnis from rats, in Cyprus, and the first report of R. felis in X. cheopis in Europe. The role of fleas (mainly X. cheopis) was confirmed in the epidemiologic cycle of murine typhus in Cyprus by interrelation of current results with those of previous studies. The geographic distribution of fleas coincided with the geographic distribution of the pathogen they can harbor, which emphasizes the potential risk of flea-transmitted infections in Cyprus.
Topics: Animals; Cyprus; Rats; Rickettsia felis; Rickettsia typhi; Siphonaptera
PubMed: 21118938
DOI: 10.4269/ajtmh.2010.10-0118 -
Infection and Immunity Jul 1972L cells that had been exposed to 3,000 r of (60)Co the previous day were used to study the growth and metabolism of Rickettsia typhi and R. akari. Viable (unirradiated)...
L cells that had been exposed to 3,000 r of (60)Co the previous day were used to study the growth and metabolism of Rickettsia typhi and R. akari. Viable (unirradiated) L cells were used to study the effect of rickettsial infection on host-cell metabolism. Monolayers were infected with a rickettsial multiplicity of 1.2 and given Eagle's minimal essential medium containing 25 mmN-2-hydroxyethylpiperazine-N'-2'-ethanesulfonic acid buffer and 10% calf serum. At various intervals, cycloheximide (2 mug/ml) was added to one set of cultures, to inhibit eukaryotic protein and deoxyribonucleic acid (DNA) metabolism; phosphate-buffered saline (PBS) was added to another set. After 1 hr, the cultures received a mixture of 15 (14)C-labeled amino acids or adenine-8-(14)C. The cultures were harvested 16 hr later and were tested for incorporation of labeled carbon into the fraction precipitated by cold trichloroacetic acid. Viable cells were exposed to thymidine-2-(14)C for 2-hr periods. Infectivity of R. typhi increased to a peak of 150 to 400 hemolytic units/culture on day 4; the titer remained approximately the same on days 5 and 6, and declined rapidly on day 7. Total amino acid incorporation was about the same in infected and uninfected cultures up to day 6, but metabolic activity was reduced to a negligible level on day 7 in infected cells. Cycloheximide-resistant activity was higher in the infected cultures, with a peak equivalent to one-half the total activity at day 4 to 5. Total as well as cycloheximide-resistant adenine incorporation was higher in the infected cells between days 3 and 5 after infection, with a peak at day 3 to 4. Somewhat similar results were obtained with R. akari, except that the cycle of infection and of cycloheximide-resistant activity proceeded and was completed more rapidly. (14)C-DNA of both rickettsiae was isolated from infected cultures that had received labeled adenine. With labeled thymidine, which was not incorporated by the rickettsiae, it was shown that R. typhi and R. akari differ considerably in their effects on the host cell. R. typhi elicited moderate inhibition, whereas R. akari infection led to a complete inhibition of thymidine incorporation by the third day, at the time of highest rickettsial activity. It is concluded that rickettsiae have the necessary enzymes for protein and nucleic acid synthesis, but, thus far, these enzymes have been activated or induced only in an intracellular environment.
Topics: Adenine; Amino Acids; Animals; Carbon Isotopes; Cobalt Isotopes; Cycloheximide; DNA, Bacterial; Erythrocytes; Hemolytic Plaque Technique; L Cells; Radiation Effects; Rickettsia; Rickettsia typhi; Sheep; Time Factors
PubMed: 4628863
DOI: 10.1128/iai.6.1.50-57.1972 -
Veterinary Research 2009In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with... (Review)
Review
In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed.
Topics: Animals; Insect Vectors; Phthiraptera; Rickettsia; Rickettsia Infections; Siphonaptera
PubMed: 19036234
DOI: 10.1051/vetres:2008050 -
MMWR. Morbidity and Mortality Weekly... Dec 2003Murine typhus, a zoonotic disease caused by Rickettsia typhi, is uncommon in the United States. Hawaii typically reports five or six cases annually; however, 47 cases...
Murine typhus, a zoonotic disease caused by Rickettsia typhi, is uncommon in the United States. Hawaii typically reports five or six cases annually; however, 47 cases were reported in 2002. This report summarizes clinical data for three of these cases and describes murine typhus activity in Hawaii during 2002 and control efforts of the Hawaii Department of Health (HDH). The high number of reported cases in 2002 underscores the need for community education to prevent murine typhus and an assessment of environmental factors that might contribute to local disease transmission.
Topics: Adolescent; Adult; Hawaii; Humans; Male; Middle Aged; Rickettsia typhi; Typhus, Endemic Flea-Borne
PubMed: 14681594
DOI: No ID Found -
Life (Basel, Switzerland) Sep 2023Different vector-borne pathogens are present or have (re-)emerged in Croatia. Flaviviruses tick-borne encephalitis (TBEV), West Nile (WNV), and Usutu (USUV) are widely... (Review)
Review
Different vector-borne pathogens are present or have (re-)emerged in Croatia. Flaviviruses tick-borne encephalitis (TBEV), West Nile (WNV), and Usutu (USUV) are widely distributed in continental regions, while Toscana virus (TOSV) and sandfly fever viruses are detected at the Croatian littoral. Recently, sporadic clinical cases of Tahyna orthobunyavirus (TAHV) and Bhanja bandavirus infection and seropositive individuals have been reported in continental Croatia. Acute infections and serologic evidence of WNV, TBEV, USUV, and TAHV were also confirmed in sentinel animals and vectors. Autochthonous dengue was reported in 2010 at the Croatian littoral. Lyme borreliosis is the most widely distributed vector-borne bacterial infection. The incidence is very high in northwestern and eastern regions, which correlates with numerous records of ticks. Acute human infections are reported sporadically, but there are many records of serologic evidence of anaplasmosis in animals. Mediterranean spotted fever () and murine typhus () are the main rickettsial infections in Croatia. Human leishmaniasis is notified sporadically, while serologic evidence of leishmaniasis was found in 11.4% of the Croatian population. After the official eradication of malaria in 1964, only imported cases were reported in Croatia. Since vector-borne diseases show a growing trend, continuous monitoring of vectors is required to protect the population from these infections.
PubMed: 37763260
DOI: 10.3390/life13091856 -
Emerging Infectious Diseases Feb 2021To document the epidemiology, clinical features, and outcomes of murine typhus patients in the Canary Islands (Spain), we analyzed data that were retrospectively...
To document the epidemiology, clinical features, and outcomes of murine typhus patients in the Canary Islands (Spain), we analyzed data that were retrospectively collected for 16 years for 221 patients. Murine typhus in the Canary Islands is characterized by a high rate of complications (31.6%), mainly liver, lung, kidney or central nervous system involvement.
Topics: Animals; Humans; Liver; Mice; Retrospective Studies; Rickettsia typhi; Spain; Typhus, Endemic Flea-Borne
PubMed: 33496241
DOI: 10.3201/eid2702.191695 -
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