Objective: To establish and optimize a TaqMan-probe quantitative real-time PCR (qPCR) assay for the detection of 7 important Rickettsiales pathogens and simultaneous identification of the infection types. Methods: Based on the ompB gene of Rickettsia prowazekii, Rickettsia mooseri and spotted fever group rickettsiae, the groEL gene of Orientia tsutsugamushi, the 16S rRNA of Ehrlichia chaffeensis, the gltA gene of Anaplasma phagocytophilum and the com1 gene of Coxiella burnetii, we synthesized primers and TaqMan-probes and optimized the reaction system and reaction process to same solution. The sensitivity, specificity and reproducibility of this assay were evaluated and the assay was used for the detection of simulated and actual samples. Results: The Ct value of the standard curves of the 7 pathogens showed a good linear relationship with the number of DNA copies (all R² >0.990 0), the minimum detection limit was 10 copies/μl, showing good specificity. In the 96 tick nucleic acid extracts, Coxiella burnetii was detected in 1 sampleand spotted fever group Rickettsiae was detected in 3 samples. In the 80 blood samples from patients with undefined febrile illness, Orientia tsutsugamushi was detected in 1 sample and spotted fever group rickettsiae was detected in 2 samples. Conclusions: In this study, based on the established TaqMan-probe qPCR assay, the reaction system and reaction condition of the 7 important pathogens of Rickettsiales were optimized to the same solution. This method overcomes the shortcomings of using different reaction systems and reaction conditions for different pathogens, which can precisely identify the species of 7 important pathogens of Rickettsiales in clinical sample detections and is important for the infection type identification and laboratory detection time reduction to facilitate precise treatment of the patients.
Humans ; Rickettsiales ; Real-Time Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; Reproducibility of Results ; Orientia tsutsugamushi ; Spotted Fever Group Rickettsiosis

Rickettsial infections (Rickettsioses) are the causes of acute fever found in Thailand. It is classified as acute febrile illnesses transmitted by bloodsucking arthropod vectors (tick, flea, and chigger). This research investigated pathogens of scrub typhus in vectors from Bangkaew District, Phatthalung Province. A total of 303 pools of vector samples were ticks (Rhipicephalus sanguineus, R. microplus, and Haemaphysalis sp.), fleas (Ctenocephalides felis orientis, C. f. felis, and C. canis), and chiggers (Leptotrombidium deliense, Aschoschoengastia indica, Blankaartia acuscutellaris and Walchia disparunguis pingue) collected from reservoir hosts (dogs and rodents). The 17 and 56 kDa gene of Rickettsia causing scrub typhus were found in 29% of ticks and 98% of flea. DNA sequence analysis reveeled the detected strains were R. asembonensis and Rickettsia sp. cf1 and 5.The chiggers, 1%, were infected with Rickettsia strain TA763, a pathogen of scrub typhus.
Animals ; Arthropod Vectors ; Cats ; Felis ; Fever ; Orientia tsutsugamushi ; Rickettsia ; Scrub Typhus ; Sequence Analysis, DNA ; Siphonaptera ; Thailand ; Ticks ; Trombiculidae

OBJECTIVES: Chigger mites are vectors for scrub typhus. This study evaluated the annual fluctuations in chigger mite populations and Orientia tsutsugamushi infections in South Korea.METHODS: During 2006 and 2007, chigger mites were collected monthly from wild rodents in 4 scrub typhus endemic regions of South Korea. The chigger mites were classified based on morphological characteristics, and analyzed using nested PCR for the detection of Orientia tsutsugamushi.RESULTS: During the surveillance period, the overall trapping rate for wild rodents was 10.8%. In total, 17,457 chigger mites (representing 5 genera and 15 species) were collected, and the average chigger index (representing the number of chigger mites per rodent), was 31.7. The monthly chigger index was consistently high (> 30) in Spring (March to April) and Autumn (October to November). The mite species included Leptotrombidium pallidum (43.5%), L. orientale (18.9%), L. scutellare (18.1%), L. palpale (10.6%), and L. zetum (3.6%). L. scutellare and L. palpale populations, were relatively higher in Autumn. Monthly O. tsutsugamushi infection rates in wild rodents (average: 4.8%) and chigger mites (average: 0.7%) peaked in Spring and Autumn.CONCLUSION: The findings demonstrated a bimodal pattern of the incidence of O. tsutsugamushi infections. Higher infection rates were observed in both wild rodents and chigger mites, in Spring and Autumn. However, this did not reflect the unimodal incidence of scrub typhus in Autumn. Further studies are needed to identify factors, such as human behavior and harvesting in Autumn that may explain this discordance.
Globus Pallidus ; Humans ; Incidence ; Korea ; Mites ; Orientia tsutsugamushi ; Polymerase Chain Reaction ; Rodentia ; Scrub Typhus ; Trombiculidae

Rodents are well-known reservoirs and vectors of many emerging and re-emerging infectious diseases, but little is known about their role in zoonotic disease transmission in Bhutan. In this study, a cross-sectional investigation of zoonotic disease pathogens in rodents was performed in Chukha district, Bhutan, where a high incidence of scrub typhus and cases of acute undifferentiated febrile illness had been reported in people during the preceding 4–6 months. Twelve rodents were trapped alive using wire-mesh traps. Following euthanasia, liver and kidney tissues were removed and tested using PCR for Orientia tsutsugamushi and other bacterial and rickettsial pathogens causing bartonellosis, borreliosis, human monocytic ehrlichiosis, human granulocytic anaplasmosis, leptospirosis, and rickettsiosis. A phylogenetic analysis was performed on all rodent species captured and pathogens detected. Four out of the 12 rodents (33.3%) tested positive by PCR for zoonotic pathogens. Anaplasma phagocytophilum, Bartonella grahamii, and B. queenslandensis were identified for the first time in Bhutan. Leptospira interrogans was also detected for the first time from rodents in Bhutan. The findings demonstrate the presence of these zoonotic pathogens in rodents in Bhutan, which may pose a risk of disease transmission to humans.
Anaplasma ; Anaplasma phagocytophilum ; Anaplasmosis ; Animals ; Bartonella ; Bartonella Infections ; Bhutan ; Communicable Diseases, Emerging ; Ehrlichiosis ; Euthanasia ; Humans ; Incidence ; Kidney ; Leptospira ; Leptospira interrogans ; Leptospirosis ; Liver ; Orientia tsutsugamushi ; Polymerase Chain Reaction ; Rodentia ; Scrub Typhus ; Zoonoses

We present a patient with scrub typhus complicated with a splenic infarction. A 40-year-old man visited the emergency medical center complaining of fever for the previous week. He had no past medical history, but reported engaging in outdoor activities. Examination revealed a maculopapular rash on his trunk and an eschar on his epigastrium. Abdominal computed tomography was performed to examine the cause of the tenderness on the left upper quadrant of his abdomen, which revealed a splenic infarct. The patient was diagnosed with scrub typhus based on the results of blood polymerase chain reaction testing, and genetic sequencing confirmed the presence of Orientia tsutsugamushi Boryong. His symptoms improved following doxycycline treatment.
Abdomen ; Adult ; Chungcheongnam-do ; Doxycycline ; Emergencies ; Exanthema ; Fever ; Humans ; Orientia tsutsugamushi ; Polymerase Chain Reaction ; Scrub Typhus* ; Splenic Infarction*

We present a patient with scrub typhus complicated with a splenic infarction. A 40-year-old man visited the emergency medical center complaining of fever for the previous week. He had no past medical history, but reported engaging in outdoor activities. Examination revealed a maculopapular rash on his trunk and an eschar on his epigastrium. Abdominal computed tomography was performed to examine the cause of the tenderness on the left upper quadrant of his abdomen, which revealed a splenic infarct. The patient was diagnosed with scrub typhus based on the results of blood polymerase chain reaction testing, and genetic sequencing confirmed the presence of Orientia tsutsugamushi Boryong. His symptoms improved following doxycycline treatment.
Abdomen ; Adult ; Chungcheongnam-do ; Doxycycline ; Emergencies ; Exanthema ; Fever ; Humans ; Orientia tsutsugamushi ; Polymerase Chain Reaction ; Scrub Typhus* ; Splenic Infarction*

Objective: To understand the epidemiological characteristics of scrub typhus and influencing factors in Yunnan province, and provide further information for the prevention and control of scrub typhus. Methods: Based on the incidence data of scrub typhus reported in Yunnan from 2006 to 2013, the epidemiological characteristics of scrub typhus were analyzed and related environmental factors were identified with panel negative binomial regression model. Results: A total of 8 980 scrub typhus cases were reported during 2006-2013 in Yunnan. The average annual incidence was 2.46/100 000, with an uptrend observed. Natural focus expansion was found, affecting 71.3% of the counties in 2013. The epidemic mainly occurred in summer and autumn with the incidence peak during July-October. The annual incidence was higher in females than in males. More cases occurred in children and farmers, the proportions of cases in farmers and pre-school aged children showed an obvious increase. Panel negative binomial regression model indicated that the transmission risk of scrub typhus was positive associated with monthly temperature and monthly relative humidity. Furthermore, an "U" pattern between the risk and the increased coverage of cropland and grassland as well as an "inverted-U" pattern between the risk and increased coverage of shrub were observed. Conclusion: It is necessary to strengthen the scrub typhus surveillance in warm and moist areas as well as the areas with high coverage of cropland and grassland in Yunnan, and the health education in children and farmers who are at high risk.
Child ; China/epidemiology* ; Environment ; Epidemics ; Farmers ; Female ; Humans ; Incidence ; Male ; Models, Statistical ; Orientia tsutsugamushi ; Risk Factors ; Scrub Typhus/transmission* ; Temperature

In Korea, scrub typhus usually occurs in October and November. Hemophagocytic lymphohistiocytosis (HLH) is a distinct clinical entity characterized by a high fever, pancytopenia, hepatosplenomegaly, histiocyte proliferation, and hemophagocytosis. We encountered a summertime case of severe scrub typhus presenting as HLH. A 49-year-old female complained of abdominal pain and fever 3 days in duration. On hospital day 3 she was transferred to the intensive care unit because of clinical deterioration accompanied by severe sepsis. As an eschar was evident on the right shoulder, we commenced doxycycline. Her condition improved dramatically and she was discharged on day 14. Although the indirect immunofluorescence antibody test (IFA) for Orientia tsutsugamushi was negative on admission, a repeat IFA test was positive; the antibody titer was 1:5,120 on hospital day 10. Scrub typhus should be considered during differential diagnosis in a patient with severe sepsis in any season except the fall.
Abdominal Pain ; Diagnosis, Differential ; Doxycycline ; Female ; Fever ; Fluorescent Antibody Technique, Indirect ; Histiocytes ; Humans ; Intensive Care Units ; Korea ; Lymphohistiocytosis, Hemophagocytic* ; Middle Aged ; Orientia tsutsugamushi ; Pancytopenia ; Scrub Typhus* ; Seasons ; Sepsis ; Shoulder

Scrub typhus is an infective acute febrile disorder caused by the intracellular parasite Orientia tsutsugamushi. Neurological manifestations of scrub typhus are meningoencephalitis, cerebellitis, transverse myelitis, papilledema, and cranial nerve palsy. However, opsoclonus-myoclonus syndrome associated with scrub typhus has been rarely reported. A 59-year-old man developed vertigo, nausea, vomiting, and imbalance following scrub typhus infection for eight days. Examination showed eschar at the axilla, decreased mentality, and opsoclonus-myoclonus syndrome. Video-oculography disclosed opsoclonus with an amplitude of 15°–20° and a frequency of 6–8 Hz. The serum antibody titers to Orientia tsutsugamushi were 1:5,120, and cerebrospinal fluid analysis revealed pleocytosis. Brain magnetic resonance imaging was normal. Neurological symptoms and signs completely improved by systemic steroid and antibiotics treatment. Various mechanisms including direct disseminating inflammation or indirect immune modulation may give rise to neurological complications following scrub typhus.
Anti-Bacterial Agents ; Axilla ; Brain ; Cerebrospinal Fluid ; Cranial Nerve Diseases ; Encephalitis ; Humans ; Inflammation ; Leukocytosis ; Magnetic Resonance Imaging ; Meningoencephalitis ; Middle Aged ; Myelitis, Transverse ; Nausea ; Neurologic Manifestations ; Ocular Motility Disorders ; Opsoclonus-Myoclonus Syndrome ; Orientia tsutsugamushi ; Papilledema ; Parasites ; Scrub Typhus ; Vertigo ; Vomiting

Serosurveillance for zoonotic diseases in small mammals and detection of chiggers, the vector of Orientia tsutsugamushi, were conducted from September 2014 to August 2015 in Gwangju Metropolitan Area. Apodemus agrarius was the most commonly collected small mammals (158; 91.8%), followed by Myodes regulus (8; 4.6%), and Crocidura lasiura (6; 3.5%). The highest seroprevalence of small mammals for O. tsutsugamushi (41; 26.3%) was followed by hantaviruses (24; 15.4%), Rickettsia spp. (22; 14.1%), and Leptospira (2; 1.3%). A total of 3,194 chiggers were collected from small mammals, and 1,236 of 3,194 chiggers were identified with 7 species of 3 genera: Leptotrombidium scutellare was the most commonly collected species (585; 47.3%), followed by L. orientale (422; 34.1%), Euchoengastia koreaensis (99; 8.0%), L. palpale (58; 4.7%), L. pallidum (36; 2.9%), Neotrombicula gardellai (28; 2.3%), and L. zetum (8; 0.6%). L. scutellare was the predominant species. Three of 1,236 chigger mites were positive for O. tsutsugamushi by PCR. As a result of phylogenetic analysis, the O. tsutsugamushi strain of chigger mites had sequence homology of 90.1-98.2% with Boryong. This study provides baseline data on the distribution of zoonotic diseases and potential vectors for the development of prevention strategies of vector borne diseases in Gwangju metropolitan area.
Animals ; Arvicolinae ; Chungcheongnam-do ; Globus Pallidus ; Gwangju* ; Hantavirus ; Korea* ; Leptospira ; Mammals* ; Mites ; Murinae ; Orientia tsutsugamushi* ; Polymerase Chain Reaction* ; Rickettsia ; Rodentia ; Sequence Homology ; Seroepidemiologic Studies ; Trombiculidae* ; Zoonoses*