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Infestation, Community Structure, and Seasonal Dynamics of Chiggers on Small Mammals at a Focus of Scrub Typhus in Northern Yunnan, Southwest China.

Chiggers are common ectoparasites and the exclusive vector of scrub typhus. From November 2020 to October 2021, a 12-month investigation was conducted at Waxi Village of Binchuan County, Yunnan Province of southwest China, a focus of scrub typhus. A total of 217,671 chiggers collected from 1329 small mammal hosts (belonging to 18 species) at the survey site were taxonomically identified as 115 species and 13 genera in the family Trombiculidae with high species diversity. Among the 115 chigger species identified, there were nine vector species. The prevalence (PM = 69.38%), mean abundance (MA =…

Integration of IgM ELISA and 56 kDa gene PCR in management of pediatric acute encephalitis syndrome associated with scrub typhus.

OBJECTIVES: To identify the potential target genes for detection of Orientia tsutsugamushi (OT) in pediatric acute encephalitis syndrome (pAES). METHODS: DNA was extracted from whole blood of 100 pAES cases having tested positive (n = 41) and negative (n = 59) for scrub typhus (ST) by IgM ELISA. These samples were subjected to standard PCR for 56 kDa, 47 kDa, 16 s rRNA, groEL, traD genes and the newly identified 27 kDa gene. RESULTS: Among the selected gene targets, 56 kDa demonstrated its superiority for OT detection over the other tested genes. The presence of OT was confirmed via PCR targ…

Hosts and vectors of scrub typhus in Chile: epidemiological study and molecular analyses of Orientia infection in rodents and rodent-associated mites.

Candidatus Orientia chiloensis causes scrub typhus over a wide geographical range in southern Chile. The life cycle, including vectors and reservoirs of this novel rickettsial pathogen, is incompletely understood. We analyzed rodent tissue and rodent-associated mite samples collected during a field study in six localities on Chiloé Island, where human scrub typhus cases have occurred. Using molecular methods, we detected Orientia DNA in 24.8% of rodents, belonging to five of seven captured species. Orientia-infection rates showed geographical variations, but were not influenced by rodent speci…

Геномическая бактериальная нагрузка, связанная с бактериальными генотипами и клиническими характеристиками у пациентов с скрубным тифом на острове Хайнань, Южный Китай.

Scrub tyhus () — крупнейшее фебрильное заболевание в Азиатско-Тихоокеанском регионе, вызванное микроорганизмом Orientia tsutsugamushi. Ранее было установлено, что у пациентов со смертельным заболеванием нагрузка на ДНК О. цуцугамуши в крови была значительно выше, чем у пациентов с несмертельным заболеванием и соотносится с продолжительностью болезни, присутствием эскара и содержанием печени в ферментах. В этом перспективном исследовании мы проанализировали связь нагрузки на бактериальную ДНК с клиническими особенностями, остротой заболеваний и генотипом с использованием ПЦР в режиме реального

Совпадение в аннотации оригинала
Scrub typhus, caused by mite-borne Orientia tsutsugamushi (O. tsutsugamushi), is a major febrile disease in the Asia-Pacific region. The DNA load of O. tsutsugamushi in the blood was previously found to be significantly higher in patients with fatal disease than those with non-fatal disease and correlated with the duration of illness, presence of eschar, and…

Scrub Typhus among Febrile Patients Admitted to the Department of Medicine in a Tertiary Care Centre: A Descriptive Cross-sectional Study.

INTRODUCTION: Scrub typhus is an acute febrile illness caused by obligate intracellular bacteria of the family Rickettsia after an incubation period of 6-21 days. The disease may lead to several complications such as acute hepatitis, sepsis, myocarditis, respiratory distress and disseminated vasculitis if not treated properly. The aim of the study was to find out the prevalence of scrub typhus among febrile patients admitted to the Department of Medicine in a tertiary care centre. METHOD: This descriptive cross-sectional study was conducted among febrile patients admitted to the Department of…

Detection of Immunoglobulin M and Immunoglobulin G Antibodies Against Orientia tsutsugamushi for Scrub Typhus Diagnosis and Serosurvey in Endemic Regions.

OBJECTIVE: To estimate the regional cutoff of optical density (OD) values for immuno-globulin M (IgM) antibodies against Orientia tsutsugamushi in serum and cerebrospinal fluid (CSF) for clinical diagnosis of scrub typhus and immunoglobulin G (IgG) antibodies in serum for sero-epidemiology in Gorakhpur, Uttar Pradesh, India. METHODS: We used data from a serological investigation of acute encephalitis syndrome patients (n=407) during the 2016 outbreak in Gorakhpur, India to determine the cutoff for OD values for IgM antibodies, and from community-based serosurveys (n=1991) to estimate the cuto…

Ecological and microbiological diversity of chigger mites, including vectors of scrub typhus, on small mammals across stratified habitats in Thailand.

BACKGROUND: Scrub typhus, caused by a bacterial pathogen (Orientia spp.), is a potentially life-threatening febrile illness widely distributed in the Asia-Pacific region and is emerging elsewhere. The infection is transmitted by the larval stage of trombiculid mites ("chiggers") that often exhibit low host specificity. Here, we present an analysis of chigger ecology for 38 species sampled from 11 provinces of Thailand and microbiomes for eight widespread species. RESULTS: In total, > 16,000 individual chiggers were collected from 1574 small mammal specimens belonging to 18 species across four…

Recent Increase of Human Granulocytic Anaplasmosis and Co-Infection with Scrub Typhus or Korean Hemorrhagic Fever with Renal Syndrome in Korea.

We report 17 patients with human granulocytic anaplasmosis between January 2015 and September 2018 at two tertiary university hospitals in Korea. Monthly incidence peaked in May and June. Among these patients, we identified three who were co-infected with scrub typhus, and one patient with hemorrhagic fever with renal syndrome.

A Case Report and Literature Review of Scrub Typhus With Acute Abdomen and Septic Shock in a Child-The Role of Leukocytoclastic Vasculitis and Granulysin.

UNLABELLED: Scrub typhus is becoming a clinically important cause of acute undifferentiated febrile illness in Taiwan. The incubation period is between 6 and 21 days after exposure. It is transmitted by chiggers (larva of trombiculid mite) in long grasses and in dirt-floor homes, with infection characterized by a flu-like illness of fever, headache, and myalgia lasting approximately 1 week. It has various systemic manifestations, including GI symptoms. In some, the illness progresses to multiorgan dysfunction syndrome and death. We report on a 13-year-old boy who lived in Taipei City and who h…

Bacterial microbiome of the chigger mite Leptotrombidium imphalum varies by life stage and infection with the scrub typhus pathogen Orientia tsutsugamushi.

Scrub typhus is a mites-borne rickettsiosis caused by the obligate intracellular Gram-negative bacterium Orientia tsutsugamushi. The disease is potentially life threatening and is prevalent in tropical Asia, islands of the western Pacific Ocean and northern Australia where an estimated one million cases occur annually. Orientia tsutsugamushi is transmitted by the bite of larval mites in the genus Leptotrombidium. In the present study, the composition of the microbiome in larvae, deutonymphs and adult males and females from laboratory colonies of L. imphalum that were infected as well as uninfe…

Surveillance for Scrub Typhus, Rickettsial Diseases, and Leptospirosis in US and Multinational Military Training Exercise Cobra Gold Sites in Thailand.

We report findings of field surveillance for disease vectors and the prevalence of Orientia tsutsugamushi, the causative agent for scrub typhus, and other Rickettsial species that cause murine typhus and spotted fever group rickettsioses, in chigger mites and small rodents; and Leptospira in rodent kidney, urine, and environmental water samples. The study sites included various Royal Thai Army military installations and other training sites, and surrounding areas where the multinational military training exercise Cobra Gold was conducted in Thailand in 2017 and 2018. The overall prevalence of …

Use of eschar swabbing for the molecular diagnosis and genotyping of Orientia tsutsugamushi causing scrub typhus in Quang Nam province, Vietnam.

BACKGROUND: Scrub typhus is a rickettsiosis which is caused by Orientia tsutsugamushi and occurs throughout the Asia-Pacific region. Molecular diagnosis of rickettsioses using eschar swabs has recently emerged, and may be very useful for the diagnosis of these diseases in tropical settings. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative polymerase chain reaction (qPCR) was used to detect O. tsutsugamushi DNA in whole blood and eschar swab specimens of 67 patients who were clinically suspected of scrub typhus in Quang Nam province, Vietnam. Among the 20 patients for whom both eschar and whole bl…

Comparative Accuracy of the InBios Scrub Typhus Detect IgM Rapid Test for the Detection of IgM Antibodies by Using Conventional Serology.

This study investigated the comparative accuracy of a recombinant 56-kDa type-specific antigen-based rapid diagnostic test (RDT) for scrub typhus for the detection of IgM antibodies by using conventional serology in well-characterized serum samples from undifferentiated febrile illness patients. The RDT showed high specificity and promising comparative accuracy, with 82% sensitivity and 98% specificity for samples defined positive at an IgM indirect immunofluorescence assay positivity cutoff titer of ≥1:1,600 versus 92% and 95% at ≥1:6,400, respectively.

Outcome of intravenous azithromycin therapy in patients with complicated scrub typhus compared with that of doxycycline therapy using propensity-matched analysis.

There are no well-matched, controlled studies comparing azithromycin with doxycycline for the treatment of complicated scrub typhus. A retrospective propensity score-matched case-control study was performed for patients who presented with complicated scrub typhus and were treated with doxycycline or azithromycin between 2001 and 2011. Data on comorbidities, clinical manifestations, laboratory studies, treatments, and outcomes were extracted for analysis. The clinical characteristics and outcomes of the azithromycin-treated group (n=73) were compared to those of the doxycycline-treated group (n…

[Study on the characteristics of temporal distribution and the epidemic trend of autumn-winter type scrub typhus under time series analysis].

OBJECTIVE: To explore the characteristics of temporal distribution and epidemic trend of autumn-winter type scrub typhus using the time series analysis. METHODS: Based on the data of scrub typhus collected from Shandong Diseases Reporting Information System from 2006 to 2011, both spectral analysis and moving average analysis were used to analyze the annual data of scrub typhus while scrub typhus incidence in 2012 - 2014 was forecasted. Seasonal decomposition analysis was applied to analyze the monthly data from January of 2006 to October of 2011, followed by Autoregressive Integrated Moving …

Nested polymerase chain reaction on blood clots for gene encoding 56 kDa antigen and serology for the diagnosis of scrub typhus.

PURPOSE: Scrub typhus is a zoonotic illness endemic in the Asia-Pacific region. Early diagnosis and appropriate management contribute significantly to preventing adverse outcomes including mortality. Serology is widely used for diagnosing scrub typhus. Recent reports suggest that polymerase chain reaction (PCR) could be a rapid and reliable alternative. This study assessed the utility of these tests for scrub typhus diagnosis. MATERIALS AND METHODS: Nested PCR to detect the 56 kDa antigen gene of O. tsutsugamushi was performed on blood clots from 87 individuals with clinically suspected scrub…

Восстановление и жизнеспособность цутсугамуши из упакованных красных клеток и опасность получения тифа от переливания крови.

Цель этого исследования состояла в том, чтобы определить, может ли инфекционный Ориентия цуцугамуши, этиологический агент скруба тифа, пережить обычные процедуры обработки и хранения крови. СТРАТЕГИЯ И МЕТОДЫ: Моноядерные клетки, изолированные от цельной крови при центрифуге плотности, были привиты при помощи штамма О. Цутсугамуши, штамма Карпа. Инфекция мононуклеарных клеток была подтверждена пятном Джимсы, прямым флуоресцирующим антителным анализом и цепной реакцией полимеразы с использованием демпферов, специфичных для оперона кристаллов О. Цутсугамуши. Количество рикетсиальных частиц в каж

Совпадение в аннотации оригинала
BACKGROUND: The purpose of this study was to determine whether infective Orientia tsutsugamushi, the etiologic agent of scrub typhus, could survive normal blood banking processing and storage procedures. STUDY DESIGN AND METHODS: Mononuclear cells isolated from whole blood by density gradient centrifugation were inoculated with O. tsutsugamushi, Karp strain…