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Spectrum of infections in acute febrile illness in central India.

INTRODUCTION: Infectious agent when enters in the host results in febrile illness. This may lead to increase in morbidity or even mortality … SA). All negative serum samples by immunochromatography were retested for disease-specific ELISA as scrub typhus, dengue and leptospirosis. RESULTS: Out of 270 patients, 127 (47%) were of scrub typhus, 33 (12%) were malaria cases, 47 (17.40%) were dengue, 12 (4%) were enteric fever, 5 (2%) were leptospirosis, undiagnosed were 18 (6.66%) and other infections ( …

Lack of the IFN-γ signal leads to lethal Orientia tsutsugamushi infection in mice with skin eschar lesions.

Scrub typhus is an acute febrile disease due to Orientia tsutsugamushi (Ot) infection and can be life-threatening with organ failure, hemorrhage, and fatality. Yet, little is known as to how the host reacts to Ot bacteria at early stages of infection; no reports have addressed the functional roles of type I versus type II interferon (IFN) responses in scrub typhus. In this study, we used comprehensive intradermal (i.d.) inoculation models and two clinically predominant Ot strains (Karp and Gilliam) to uncover early immune events. Karp infection induced sequential expression of Ifnb and Ifng in…

Tropical rickettsioses.

In recent years, a bewildering array of emerging rickettsial pathogens have been described throughout the world, including in the tropics. Here we present an updated overview of scrub typhus, murine typhus, and epidemic typhus. We also present an update on the emerging spotted fever group rickettsioses described in the tropics through 2005, focusing on epidemiologic and clinical data and management.

Notified Vector-Borne Diseases - China, 2005-2024.

INTRODUCTION: Vector-borne diseases (VBDs) represent a significant category of infectious diseases. Analyzing the epidemiological characteri … 20-year period. RESULTS: From 2005 to 2024, a total of 1,129,736 VBD cases were reported in China. Scrub typhus (28.17%), malaria (20.8%), hemorrhagic fever with renal syndrome (HFRS, 18.4%), dengue (12.61%), and schistosomiasis (8.42%) collectively accounted for 88.4% of all cases. Over a 20-year period, mosquito-borne and rodent-borne diseases indicated sig …

Diversification of Orientia tsutsugamushi genotypes by intragenic recombination and their potential expansion in endemic areas.

BACKGROUND: Scrub typhus is a mite-borne febrile disease caused by O. tsutsugamushi infection. Recently, emergence of scrub typhus has attracted considerable attention in several endemic countries in Asia and the western Pacific. In addition, the antigenic diversity of the intracellular pathogen has been a serious obstacle for developing effective diagnostics and vaccine. METHODOLOGY/PRINCIPAL FINDINGS: To understand the evolutionary pathway of genotypic diversification of O. tsutsugamushi and the environmental factors associated with the epidemiological features of scrub typhus, we analyzed …

Outbreak investigation of Dengue like fever in rural area of Rajasthan.

During October 2020, suddenly many cases were reported with Dengue like Illness in Sahawa village, Rajasthan. Blood samples collected from 68 patients were tested for Dengue NS1 antigen and IgM antibodies for Dengue, Chikungunya, Scrub typhus, Leptospira and Brucella by ELISA, Dengue, Chikungunya and Zika viral RNA by multiplex Polymerase Chain Reaction (PCR), 41.17% samples were positive for Dengue; 25% were positive by Dengue PCR, 17.64% for NS1 Ag,14.70% for IgM ELISA, 20.58% were positive for antibodies either for Scrub typhus (4.41%), Leptospira (7.35%) or Brucella (10.29%). Dengue was se…

Current status of mites and mite-borne diseases in India.

Mites act as the vectors of zoonotic vector-borne disease scrub typhus caused by the rickettsial pathogen Orientia tsutsugamushi. In India, scrub typhus is transmitted by the mite Leptotrombidium deliense. Rodents are the reservoirs and support the spread of this disease. Sarcoptes scabiei or the itch mite is causing scabies which is a common skin infection in India. Dermatitis, trombiculosis, and mite dust allergy are common mite-borne diseases transmitted by Pyemotidae family. D. brevis folliculorum and Demodex brevis are two major mite species found on humans also causing a disease; "Demodi…

Prevalence and heterogeneity of antibiotic resistance genes in Orientia tsutsugamushi and other rickettsial genomes.

Despite a million infections every year and an estimated one billion people at risk, scrub typhus is regarded as a neglected tropical disease. The causative bacterium Orientia tsutsugamushi, a member of rickettsiae, seems to be intrinsically resistant to several classes of antibiotics. The emergence of antibiotic-resistant scrub typhus is likely to become a global public health concern. Yet, it is unknown as to how common antibiotic resistance genes are in O. tsutsugamushi, and how variable these loci are among the genomes of rickettsiae. By using the comprehensive antibiotic resistance databa…

Широкий охват молекулярной эпидемиологии цутсугамуши в Таиланде.

Orientia tsutsugamushi, обязуемый внутриклеточный бактерий, тесно связанный с родом Рикитсия, является причинно-следственным агентом скруба тифа, одной из основных причин фебрильных заболеваний в сельских районах Азиатско-Тихоокеанского региона. Скруб тифа передается от укуса инфицированных клещей рода Лептотромбий. Регион гена 56-kDa TSA, вращающегося от переменного домена I (VDI) до переменного домена IV (VDIV), был секвенирован и использовался для генотификации 77 проб O. tsutsugamushi от человеческих пациентов, подтвержденных с помощью скруба тифа с 2001 по 2003 и 2009 по 2010 годы в разли

Совпадение в аннотации оригинала
Orientia tsutsugamushi, an obligate intracellular bacterium closely related to the genus Rickettsia, is the causative agent of scrub typhus, a major cause of febrile illness in rural areas of Asia-Pacific region. Scrub typhus is transmitted by the bite of infected mites of the genus Leptotrombidium. The region of the 56-kDa TSA gene spanning from variable do…

Imported rickettsial disease: clinical and epidemiologic features.

PURPOSE AND METHODS: The rickettsioses continue to constitute major health problems in many parts of the world. With increasing international travel, recognition of rickettsial diseases by physicians is becoming more important. The clinical features of four cases of rickettsial disease imported into Canada over a five-year period are presented; two patients with tick typhus (Rickettsia conorii), one patient with scrub typhus (R. tsutsugamushi), and one patient with murine typhus (R. typhi). We also present the North American data over the past 10 years from the Centers for Disease Control (CDC…

Humoral Immune Response to Orientia tsutsugamushi Infection: Recent Research Findings and Future Studies.

Orientia tsutsugamushi (Ot), an intracellular bacterium in the family Rickettsiaceae, is the etiological agent of scrub typhus. An understanding of immunologic responses to Ot infection, particularly immunity after infection, has remained a major gap of knowledge in the field. While it is known that anti-Ot IgG in infected humans seems to be short-lived, recent studies have reported autoreactive IgM antibodies in scrub typhus patients, including antibodies reactive against nuclear components, DNA, and platelets. Yet, mechanistic studies of B cell responses in the secondary lymphoid organs of h…

Detection of Orientia tsutsugamushi in Novel Trombiculid Mite Species in Northern Tamil Nadu, India: Use of Targeting the Multicopy traD Gene.

Detection of Orientia tsutsugamushi DNA in a trombiculid mite chigger species suggests that it might be a potential vector of scrub typhus in an endemic area. Over a period of 20 mo, 85 rats were trapped, 57 had chiggers that were identified by standard morphometric techniques. The chigger pools were assessed by performing PCR assays targeting fragments of the single-copy genes 56 kDa type-specific antigen gene (TSA56) by nested PCR and the 47 kDa (htrA) quantitative real-time PCR (qPCR). The novel traD SYBR green assay that detects a multicopy gene was also performed. In total, 27 chigger poo…

Serologic Evidence for Orientia Exposure in the Democratic Republic of Sao Tome and Principe.

Orientia tsutsugamushi is an obligate intracellular bacterium that causes scrub typhus in humans. Formerly thought to be confined to the "tsutsugamushi triangle" within the Asia-Pacific region, scrub typhus was recently identified in the Western Hemisphere. Moreover, a new species of Orientia bacterial genus was isolated from a patient in Dubai. This study investigated Orientia exposure in an African country, the Democratic Republic of Sao Tome and Principe. Two sets of samples were analyzed in the study: 240 dried blood spots (DBSs) collected in 2016 and 863 serum samples from 570 pregnant wo…

Rickettsiae exposure related to habitats of the oriental house rat (Rattus tanezumi, Temminck, 1844) in Salaya suburb, Thailand.

Rickettsial zoonotic diseases, in particular scrub typhus, murine typhus, and tick typhus, are caused by Orientia tsutsugamushi, Rickettsia typhi, and Rickettsia honei infections. Rickettsiae exposure is typically related to a rodent host in various habitats of marginal regions, including between rural areas and communities such as the Salaya suburb. This allows the oriental house rat (OHR), a highly adaptive species, to live in close proximity to the community and possibly introduce rickettsial diseases. To understand rickettsial exposure in the OHR from different habitats, knowledge of disea…

Seroepidemiological survey of rodents collected at a U.S. military installation, Yongsan Garrison, Seoul, Republic of Korea.

A seroepidemiological study of selected rodent-borne diseases (hantavirus [Seoul [SEO] virus], scrub typhus [Orientia tsutsugamushi], murine typhus [Rickettsia typhi], and leptospirosis [Leptospira interrogans]), as part of the U.S. military rodent surveillance and control program, was conducted from 2001 through 2005 at Yongsan Garrison, Seoul, Republic of Korea. Rodents were collected to determine the prevalence of rodent-borne diseases at a U.S. military installation in an urban environment. A total of 1,750 rodents representing three species was collected by using baited live traps (Tomaha…

Seroprevalence of Rickettsial Infections in Northeast India: A Population-Based Cross-Sectional Survey.

A cross-sectional survey was undertaken to estimate seroprevalence of immunoglobulin G antibodies against scrub typhus, spotted fever group rickettsiae, and typhus group rickettsiae in randomly selected 48 clusters in 12 districts of 3 Northeast states of India: Assam, Meghalaya, and Tripura. Individuals in 3 age groups (5-8, 9-17, and 18-45 years) were selected from each cluster. Sera (N = 2360) tested were collected as part of a national survey on dengue seroprevalence conducted between September 2017 and February 2018. Overall, seroprevalence of 2.5% was detected against rickettsioses, with…

Specific amplification of Rickettsia tsutsugamushi DNA from clinical specimens by polymerase chain reaction.

Polymerase chain reaction (PCR) was used to detect Rickettsia tsutsugamushi-specific DNA in clinical specimens. The primer pair used for PCR was designed from the nucleotide sequence of the gene encoding the 56-kDa antigen of the Gilliam strain. Theses primers led to a 78-bp fragment by amplifying the genomic DNAs from five serovariants, i.e., the Gilliam, Karp, Kato, Kawasaki, and Kuroki strains of R. tsutsugamushi, and also the DNA from blood clots of patients with scrub typhus, even at the early stage of onset of the disease. This indicates that this method is suitable for the diagnosis of …

Imported rickettsial infections to the United Kingdom, 2015-2020.

OBJECTIVE: The burden of imported rickettsial infection in the UK is not previously described. This retrospective review identifies rickettsial cases diagnosed at the national reference laboratory between 2015 and 2022. METHODS: Samples testing positive for spotted fever group, typhus group, and scrub typhus IgG/IgM on acute and convalescent blood samples, and/or PCR on tissue/blood were categorized as suspected, confirmed or past infection. RESULTS: 220 patients had rickettsioses, and the commonest import was acute spotted fever group infection (61%, 125/205), 54% (62/114) from South Africa…

Multicenter GeoSentinel analysis of rickettsial diseases in international travelers, 1996-2008.

We investigated epidemiologic and clinical aspects of rickettsial diseases in 280 international travelers reported to the GeoSentinel surveillance Network during 1996-2008. Of these 280 travelers, 231 (82.5%) had spotted fever (SFG) rickettsiosis, 16 (5.7%) scrub typhus, 11 (3.9%) Q fever, 10 (3.6%) typhus group (TG) rickettsiosis, 7 (2.5%) bartonellosis, 4 (1.4%) indeterminable SFG/TG rickettsiosis, and 1 (0.4%) human granulocytic anaplasmosis. One hundred ninety-seven (87.6%) SFG rickettsiosis cases were acquired in sub-Saharan Africa and were associated with higher age, male gender, travel …

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Scrub typhus is caused by the mite-borne bacterium Orientia tsutsugamushi. Imported cases have been suspected in Denmark but no diagnostic method has yet been available to confirm the diagnosis. This is a case report of a 38-year-old male admitted to hospital with high fever, severe malaise and headache after returning from Malaysia. Scrub typhus was suspected and the patient recovered after one week of doxycycline treatment. The pathogen was identified by use of microbiome 16S/18S rRNA next-generation sequencing on ethylenediamine tetraacetic acid (EDTA) blood, which in the future may serve a…