scholarly journals Monitoring Chigger Mites for Orientia tsutsugamushi in Field Small Mammals in Hwaseong-si, Gyeonggi-do, Korea, 2019-2020

2021 ◽  
Vol 59 (3) ◽  
pp. 319-324
Author(s):  
Young Yil Bahk ◽  
Seong Kyu Ahn ◽  
Jinyoung Lee ◽  
Hyung Wook Kwon ◽  
Sung Jong Hong ◽  
...  
Keyword(s):  
Small Mammals ◽  
Scrub Typhus ◽  
Rapid Diagnosis ◽  
The Other ◽  
Orientia Tsutsugamushi ◽  
Chigger Mite ◽  
Apodemus Agrarius ◽  
Tsutsugamushi Disease ◽  
Pcr Test

Incidence of tsutsugamushi disease (scrub typhus) caused by Orientia tsutsugamushi, is steadily increasing. It is a mite-borne disease transmitted by chigger mites. In this study, the chigger mites were collected from field small mammals in Hwaseong-si (city), Gyeonggi-do (province), Korea, 2019 and 2020. The field small mammals captured were 56 Apodemus agrarius (94.9%) and 3 Crocidura lasiura (5.1%). A total of 7,531 chigger mites were collected from the captured small mammals. Using PCR test, 153 chigger mite pools were examined and 17 pools were reported positive for O. tsutsugamushi. The O. tsutsugamushi were identified to 5 strains; Jecheon strain was most prevalent, followed by Boryong strain. The other strains were OI011, Taguchi, and Shimokoshi. Collectively, these results provide essential regional information on mite-borne tsutsugamushi disease in the Hwaseong-si, and further contribute to bring awareness and rapid diagnosis for the tsutsugamushi disease.

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

PLoS ONE ◽  
2018 ◽  
Vol 13 (12) ◽  
pp. e0208327 ◽  
Author(s):  
Loganathan Ponnusamy ◽  
Alexandra C. Willcox ◽  
R. Michael Roe ◽  
Silas A. Davidson ◽  
Piyada Linsuwanon ◽  
...  
Keyword(s):  
Scrub Typhus ◽  
Life Stage ◽  
Orientia Tsutsugamushi ◽  
Chigger Mite ◽  
Bacterial Microbiome

scholarly journals Observations on the Weil-Felix Reaction in Tsutsugamushi Disease

1931 ◽  
Vol 31 (3) ◽  
pp. 352-360 ◽  
Author(s):  
J. W. Wolff
Keyword(s):  
Positive Reaction ◽  
Present State ◽  
Scrub Typhus ◽  
Disease Type ◽  
The Other ◽  
Considerable Proportion ◽  
Agglutination Reaction ◽  
Tsutsugamushi Disease ◽  
Adequate Method

1. The Weil-Felix reaction in a series of forty-five cases of tsutsugamushi disease (type Schüffner) is recorded.2. The agglutination reaction was negative in fifteen cases, the other thirty showing a positive reaction with the “Kingsbury” strain of B. proteus X.3. The Weil-Felix reaction is not regarded as an adequate method for differentiating tsutsugamushi disease from scrub typhus, since high titres (1 in 1000) occur in a considerable proportion of cases of tsutsugamushi disease.4. In the present state of our knowledge of the two diseases it is recommended that they should be separated according to the presence or absence of a primary ulcer and bubo.

scholarly journals Hemophagocytic lymphohistiocytosis: an unusual complication in Orientia tsutsugamushi disease (scrub typhus).

2014 ◽  
Vol 7 ◽  
pp. e2015008 ◽  
Author(s):  
Aneesh Basheer ◽  
Somanath Padhi ◽  
Vinoth Boopathy ◽  
Saumyaranjan Mallick ◽  
Shashikala Nair ◽  
...  
Keyword(s):  
Antibiotic Therapy ◽  
Hemophagocytic Lymphohistiocytosis ◽  
Scrub Typhus ◽  
Ferritin Level ◽  
Outcome Data ◽  
Unusual Complication ◽  
Orientia Tsutsugamushi ◽  
Tsutsugamushi Disease ◽  
Concise Review ◽  
Tertiary Center

Background: Hemophagocytic lymphohistiocytosis (HLH) is an uncommon, potentially fatal, hyperinflammatory syndrome that may rarely complicate the clinical course of Orientia tsutsugamushi disease (scrub typhus). Methods: We describe here the clinicopathological features, laboratory parameters, management, and outcome data of three adult patients (1 female, 2 males) with scrub typhus associated HLH from a tertiary center with a brief and concise review of international literature. Results: All three patients satisfied the HLH-2004 diagnostic criteria; one had multi organ dysfunction with “sky high” ferritin level; and all had a dramatic recovery following doxycyclin therapy. Literature review from January 1990 to March 2014 revealed that scrub typhus associated HLH were reported in 21 patients, mostly from the scrub endemic countries of the world. These included 11 females and 10 males with mean age of 35 years (range; 8 months to 81 years). Fifteen of 17 patients (where data was available) had a favorable outcome following early serological diagnosis and initiation of definitive antibiotic therapy with (N=6) or without (N=9) immunosuppressive/immunomodulator therapy. Mutation analysis for primary HLH was performed in one patient only, and HLH-2004 protocol was used in two patients. Conclusion: We suggest that HLH should be considered in severe cases of scrub typhus especially if associated with cytopenia (s), liver dysfunction, and coagulation abnormalities.  Further studies are required to understand whether an immunosuppressive and/or immunomodulator therapy could be beneficial in those patients who remain unresponsive to definitive antibiotic therapy.

Field assessment of Orientia tsutsugamushi infection in small mammals and its association with the occurrence of human scrub typhus in Taiwan

Acta Tropica ◽  
2014 ◽  
Vol 131 ◽  
pp. 117-123 ◽  
Author(s):  
Pey-Ru Lin ◽  
Hui-Ping Tsai ◽  
Ming-Hui Weng ◽  
Hung-Chi Lin ◽  
Kuo-Ching Chen ◽  
...  
Keyword(s):  
Small Mammals ◽  
Scrub Typhus ◽  
Orientia Tsutsugamushi ◽  
Field Assessment

scholarly journals Nationwide Incidence of Chigger Mite Populations and Molecular Detection of Orientia tsutsugamushi in the Republic of Korea, 2020

2021 ◽  
Vol 9 (8) ◽  
pp. 1563
Author(s):  
Min-Goo Seo ◽  
Bong-Goo Song ◽  
Tae-Kyu Kim ◽  
Byung-Eon Noh ◽  
Hak Seon Lee ◽  
...  
Keyword(s):  
Temporal Distribution ◽  
Republic Of Korea ◽  
Orientia Tsutsugamushi ◽  
Wild Rodents ◽  
Chigger Mite ◽  
Disease Epidemiology ◽  
Tsutsugamushi Disease ◽  
Control And Prevention ◽  
Disease Risks ◽  
The Republic

The Korea Disease Control and Prevention Agency has established regional centers at 16 locations to monitor vectors and pathogens. We investigated the geographical and temporal distribution of chigger mite populations to understand tsutsugamushi disease epidemiology in 2020. To monitor weekly chigger mite populations, 3637 chigger mites were collected from sticky chigger mite traps in autumn. Chigger mites appeared from the first week of October to the third week of December, peaking in the fourth week of October. The predominant species were Leptotrombidium scutellare, Leptotrombidium palpale, Neotrombicula kwangneungensis, Neotrombicula tamiyai, and Leptotrombidium pallidum. To monitor Orientia tsutsugamushi infection in chigger mites, 50,153 chigger mites were collected from 499 trapped wild rodents in spring and autumn, with a chigger index of 100.5. Approximately 50% of chigger mites were pooled into 998 pools, and the minimum infection rate (MIR) of O. tsutsugamushi was 0.1%. Jeongeup had the highest MIR for O. tsutsugamushi (0.7%). The Kato-related genotype was the most common (52.2%), followed by the Karp-related (17.4%), Boryong (13.0%), JG-related (8.7%), Shimokoshi (4.3%), and Kawasaki (4.3%) genotypes. Ecological and geographical studies focusing on the basic ecology and pathology of mites will improve our understanding of tsutsugamushi disease risks in the Republic of Korea.

Host selection and seasonal fluctuation of Leptotrombidium deliense (Walch, 1922) (Trombidiformes: Trombiculidae) at a localized area of southern Yunnan, China

2019 ◽  
Vol 24 (11) ◽  
pp. 2253-2271 ◽  
Author(s):  
Yan Lv ◽  
Xianguo Guo ◽  
Daochao Jin ◽  
Wenyu Song ◽  
Rong Fan ◽  
...  
Keyword(s):  
Small Mammals ◽  
Host Selection ◽  
Scrub Typhus ◽  
Seasonal Fluctuation ◽  
Field Investigation ◽  
Male Rats ◽  
Tsutsugamushi Disease ◽  
Two Peaks ◽  
The Village ◽  
Taxonomic Categories

As an independent species of chigger mites, Leptotrombidium deliense (Walch 1922) is the most important and powerful vector of scrub typhus (tsutsugamushi disease) in the south of China. Located in the southwest of China, Yunnan province, especially southern Yunnan, is an important focus of scrub typhus. A localized area, Jingha village in southern Yunnan, was chosen as the target site and a field investigation at the village was carried out for 12 consecutive months from April 2016 to March 2017. The investigation is an attempt to illustrate the small mammals host selection and seasonal fluctuation of L. deliense at a fixed geographical site within the focus of scrub typhus, and the selected localized area makes this possible. A total of 2,434 hosts were captured and examined, including rodents and some other “rodent-like” small mammals. Of the identified 15 host species, L. deliense was found on 73.33% of them (11 species of hosts), but 88.61% of the mites were from the Southeast Asian house rats, Rattus brunneusculus. Of 10 genera, 5 families and 4 orders of identified hosts, more than 80.00% of them were infested with L. deliense with a prominent cross infestation among different taxonomic categories of hosts, but the majority of the mites (96.60%) were collected from rodents (the order Rodentia), especially the rats in the genus Rattus (92.95%). It suggests that L. deliense prefers rodents (especially the Rattus rats) to some other small mammals although it has a low host specificity. Rattus brunneusculus is the major host of the mite in the investigated site. The female R. brunneusculus rats harbored more L. deliense mites than the male rats (P<0.01). The spatial distribution pattern of L. deliense on the hosts was determined as aggregated distribution. L. deliense mites were collected every month with two peaks (in July and October), belonging to the summer-autumn type. The first peak in July was much higher than the second peak in October. The monthly fluctuation of L. deliense was highly in accordance with that of the rainfall, which suggests the summer season with plentiful rainfall benefits the occurrence of this powerful vector of scrub typhus, L. deliense.

scholarly journals Orientia tsutsugamushi dynamics in vectors and hosts: ecology and risk factors for foci of scrub typhus transmission in northern Thailand

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ivo Elliott ◽  
Neeranuch Thangnimitchok ◽  
Kittipong Chaisiri ◽  
Tri Wangrangsimakul ◽  
Piangnet Jaiboon ◽  
...  
Keyword(s):  
High Risk ◽  
Small Mammals ◽  
Disease Ecology ◽  
Scrub Typhus ◽  
Disease Risk ◽  
Diversity Index ◽  
Asia Pacific ◽  
Orientia Tsutsugamushi ◽  
Northern Thailand ◽  
Field Samples

Abstract Background Scrub typhus is an important neglected vector-borne zoonotic disease across the Asia–Pacific region, with an expanding known distribution. The disease ecology is poorly understood, despite the large global burden of disease. The key determinants of high-risk areas of transmission to humans are unknown. Methods Small mammals and chiggers were collected over an 18-month period at three sites of differing ecological profiles with high scrub typhus transmission in Chiang Rai Province, northern Thailand. Field samples were identified and tested for Orientia tsutsugamushi by real-time PCR. The rates and dynamics of infection were recorded, and positive and negative individuals were mapped over time at the scale of single villages. Ecological analyses were performed to describe the species richness, community structure and interactions between infected and uninfected species and habitats. Generalised linear modelling (GLM) was applied to examine these interactions. Results The site with the highest rates of human infection was associated with the highest number of infected chigger pools (41%), individual chiggers (16%), proportion of the known vector species Leptotrombidium deliense (71%) and chigger index (151). Chigger species diversity was lowest (Shannon diversity index H′: 1.77) and rodent density appeared to be high. There were no consistent discrete foci of infection identified at any of the study sites. The small mammals Rattus tanezumi and Bandicota indica and the chiggers L. deliense and Walchia kritochaeta emerged as central nodes in the network analysis. In the GLM, the end of the dry season, and to a lesser extent the end of the wet season, was associated with O. tsutsugamushi-infected small mammals and chiggers. A clear positive association was seen between O. tsutsugamushi-positive chigger pools and the combination of O. tsutsugamushi-positive chigger pools and O. tsutsugamushi-positive small mammals with lowland habitats. Conclusions These findings begin to reveal some of the factors that may determine high-risk foci of scrub typhus at a fine local scale. Understanding these factors may allow practical public health interventions to reduce disease risk. Further studies are needed in areas with diverse ecology. Graphical abstract

CNS Manifestations in Orientia tsutsugamushi Disease (Scrub Typhus) in North India

2016 ◽  
Vol 83 (7) ◽  
pp. 634-639 ◽  
Author(s):  
Ashwani Kumar Sood ◽  
Lokesh Chauhan ◽  
Hemant Gupta
Keyword(s):  
Scrub Typhus ◽  
North India ◽  
Orientia Tsutsugamushi ◽  
Tsutsugamushi Disease

Scrub typhus (Orientia tsutsugamushi), A rapidly spreading epidemic in Chennai - A standalone lab experience

2016 ◽  
Vol 5 (09) ◽  
pp. 4896
Author(s):  
Sripriya C.S.* ◽  
Shanthi B. ◽  
Arockia Doss S. ◽  
Antonie Raj I. ◽  
Mohana Priya
Keyword(s):  
Scrub Typhus ◽  
Clinical Symptoms ◽  
Clinical Manifestations ◽  
Febrile Illness ◽  
Orientia Tsutsugamushi ◽  
The Past ◽  
Igm Elisa ◽  
The Mean ◽  
Specific Symptoms ◽  
Symptoms And Signs

Scrub typhus (Orientia tsutsugamushi), is a strict intracellular bacterium which is reported to be a recent threat to parts of southern India. There is re-emergence of scrub typhus during the past few years in Chennai. Scrub typhus is an acute febrile illness which generally causes non-specific symptoms and signs. The clinical manifestations of this disease range from sub-clinical disease to organ failure to fatal disease. This study documents our laboratory experience in diagnosis of scrub typhus in patients with fever and suspected clinical symptoms of scrub typhus infection for a period of two years from April 2014 to April 2016 using immunochromatography and IgM ELISA methods. The study was conducted on 648 patients out of whom 188 patients were found to be positive for scrub typhus. Results also showed that pediatric (0 -12 years) and young adults (20 – 39 years) were more exposed to scrub typhus infection and female patients were more infected compared to male. The study also showed that the rate of infection was higher between September to February which also suggested that the infection rate is proportional to the climatic condition. Statistical analysis showed that the mean age of the patients in this study was 37.6, standard deviation was 18.97, CV % was 50.45. 

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