• Journal of Environmental Health Sciences
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• v.42 no.1
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• pp.41-52
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• 2016

Objectives: Scrub typhus is one of the most prevalent vector-borne diseases. It is caused by Orientia tsutsugamushi, which is transmitted when people are bitten by infected chigger mites. This study aims at quantifying the association between the incidence of scrub typhus and meteorological factors in Jeollabuk-do Province over the period 2001-2015. Methods: Reported cases of scrub typhus were collected from the website of the Disease Web Statistical System supported by the Korea Centers for Disease Control and Prevention (KCDC). Simultaneous meteorological data, including temperature, rainfall, relative humidity, and sunshine duration were collected from the website of the National Climate Data Service System by the Korea Meteorological Administration. Correlation and regression analyses were applied to identify the association between the incidence of scrub typhus and meteorological factors. Results: The general epidemiological characteristics of scrub typhus in Jeollabuk-do Province were similar to those nationwide for sex, age, and geographical distribution. However, the annual incidence rate (i.e., cases per 100,000) of scrub typhus in Jeollabuk-do Province was approximately four times higher than all Korea's 0.9. The number of total cases was the highest proportion at 13.3% in Jeonbuk compared to other regions in Korea. The results of correlation analysis showed that there were significant correlations between annual cases of scrub typhus and monthly data for meteorological factors such as temperature and relative humidity in late spring and summer, especially in the case of temperature in May and June. The results of regression analysis showed that determining factors in the regression equation explaining the incidence of scrub typhus reached 46.2% and 43.5% in May and June. Using the regression equation, each 1oC rise in the monthly mean temperature in May or June may lead to an increase of 38 patients with scrub typhus compared to the annual mean of incidence cases in Jeollabuk-do Province. Conclusion: The result of our novel attempts provided rational evidence that meteorological factors are associated with the occurrence of scrub typhus in Jeollabuk-do. It should therefore be necessary to observe the trends and predict patterns of scrub typhus transmission in relation to global-scale climate change. Also, action is urgently needed in all areas, especially critical regions, toward taking steps to come up with preventive measures against scrub typhus transmission.

• Annals of Clinical Neurophysiology
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• v.21 no.2
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• pp.98-101
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• 2019

A 64-year-old man presented with facial diplegia occurring 2 weeks after scrub typhus diagnosis. The serum scrub typhus antibody titer was elevated to 1:5120. Brain magnetic resonance imaging revealed contrast-enhancement of the signal for both facial nerves. He was administered prednisolone. After two weeks, the symptoms improved, and after one month, he completely recovered from facial diplegia. This is the first case in the literature in which the patient exhibited facial diplegia, a delayed complication, in scrub typhus. Facial diplegia should be considered a type of cranial nerve palsy that may occur as a delayed complication of scrub typhus.

• Mass Spectrometry Letters
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• v.12 no.3
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• pp.76-80
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• 2021

Scrub typhus is an acute febrile disease caused by the pathogenic bacterium Orientia tsutsugamushi, belonging to the Rickettsiaceae family. The shotgun proteomic analysis was performed using the sera of scrub typhus patients to identify the proteins having their origin in O. tsutsugamushi. Three different databases approaches were used for the identification of the proteomes. We identified the RsmD, an RNA methyltransferase as the commonly detected protein from all three approaches. This protein was not detected in the sera of healthy negative controls. We believe that this protein is a potential biomarker of Orientia tsutsugamushi present in the sera of scrub typhus patients.

• Clinical and Experimental Pediatrics
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• v.60 no.4
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• pp.124-127
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• 2017

Purpose: Chloramphenicol and tetracycline are not recommended for treating scrub typhus in pediatric patients because of potential side effects, such as aplastic anemia or tooth discoloration. While clarithromycin has recently been used in adults, few reports have been published on its effects in pediatric patients. We report the clinical profiles of pediatric scrub typhus and the effects of clarithromycin on scrub typhus in children. Methods: We retrospectively analyzed medical records of 56 children with scrub typhus who were admitted between 2004 and 2013 to Chonbuk National University Hospital, Jeonju, Korea. Cases were divided into 3 groups based on the treatment drug (chloramphenicol, azithromycin, and clarithromycin). We compared their clinical manifestations and laboratory findings. Results: All patients exhibited fever and rash. Other common clinical manifestations were eschars (66%), lymphadenopathy (48%), upper respiratory symptoms (42%), abdominal pain (32%), and hepatosplenomegaly (14%). Elevated levels of C-reactive protein, erythrocyte sedimentation rates, aspartate transaminase, and alanine transaminase were detected in 95%, 96%, 84%, and 77% of patients, respectively. Additionally, decreased platelet and white blood cell levels were observed in 43% and 36% of patients, respectively. There were no statistical differences between the treatment groups in mean age (P=0.114) or sex (P=0.507). However, time to defervescence after the treatments differed significantly, being the shortest in the clarithromycin group (P=0.019). All patients recovered without complications related to the disease or drugs. Conclusion: Clarithromycin was as effective as chloramphenicol and azithromycin in pediatric scrub typhus patients and may be used as a first-line treatment drug.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.759-767
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• 1995

One hundred twelve domestic dog sera were collected from Kyonggi, Kanngwon, Cholla, and Kyongsang province. All the sera were examined by immunofluorescence antibody test(IFAT) against scrub typhus, murine typhus and spotted fever group rickettsia infection. The antibody prevalence was 5.40%(6/112) against scrub typhus. The sero-prevalence rates of scrub typhus were 16.30%(5/31) in Cholla and 5.90%(1/17)in Kyonggi areas. The prevalence of scrub typhus was higher in older dogs that were 6 years or more. The antibody prevalence was 8.04%(9/112) against murine typhus. The sero-positive rates to murine typhus were 5.88%(1/17) in Kyonggi, 8.33%(2/24) in Kangwon, 9.68%(3/31) in Cholla, and 7.50%(3/40) in Kyongsang areas, respectively. The sero-positive dogs to murine typhus were widely distributed throughout all age groups from 2 months to above 9 years old. The antibody prevalence was 16.96%(19/112) for spotted fever group rickettsial infection. The sero-positive rates of spotted fever group rickettsia were 11.76%(2/17) in Kyonggi, 12.90%(4/31) in Cholla, and 32.50%(13/40) in Kyongsang areas. The sero-positive dogs to spotted fever group rickettsia were observed at all age groups of dog. The sero-positive prevalence between sex showed higher in female than in male except for spotted fever group rickettsia infection.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.377-382
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• 1998

Hemorrhagic fever with renal syndrome (HFRS), scrub typhus, murine typhus and leptospirosis have been the principal acute febrile diseases in Korea. To evaluate the seroepidemiologic patterns of acute febrile illness, sera collected from 2,423 patients in 1996 were examined for antibodies against Hantaan virus, Orientia tsutsugamushi, Rickettsia typhi, and Borrelia burgdorferi by indirect immunofluorescent antibody technique (IFA) and macroscopic agglutination test for Leptospira interogans. Seropositive cases against Otsutsugamushi, Rickettsia typhi, Leptospira interogans and Hantaan virus were 192 (7.9%), 193 (8.0%), 12 (0.5%) and 324 (13.4%), respectively. Male was more affected in HFRS and murine typhus contrasting to scrub typhus and leptospirosis in female. Most positive cases occurred during October and November for scrub typhus, and during November and December for HFRS. These results showed similar patterns with previous epidemical data for recent couple of years, and possibly implied no significant changes occurred in ecologic situations for acute febrile diseases in Korea.

• Journal of agricultural medicine and community health
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• v.37 no.1
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• pp.1-11
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• 2012

Objectives: To survey the awareness of patient to scrub typhus to provide data for education and communication concerning scrub typhus. Methods: Patients with scrub typhus (case group, n=299) and people without scrub typhus within the previous 2 years (control group, n=598) were matched for age (within 5 years), gender, and occupation (farmer or non-farmer). The participants were recruited from 15 study areas between October and December 2006. Results: The awareness rate of scrub typhus was 75.1%, and was significantly higher than in the case group (79.4% vs. 66.6%, respectively; p<0.01). The major routes of awareness were from 'past history of scrub typhus in family members or neighbors' (54.9%), 'television' (28.3%), and their past history of scrub typhus (5.5%). The average correct rate of scrub typhus was 48.4%, and the correct response rate of cases was significantly higher than controls (p<0.01). Especially, the correct rate of etiology, incubation period, route of transmission, and acquired immunity was <40%. Through conditional logistic regression test, the factor significantly associated with awareness in case group was age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.94-0.98). And the factors associated with awareness in control group were female (OR, 1.56; 95% CI, 1.03-2.36) age (OR, 0.98; 95% CI, 0.96-0.99), family history of scrub typhus (OR, 10.18; 95% CI, 1.37-75.99), history of receiving prevention education (OR, 8.47; 95% CI, 1.14-63.00). Conclusions: The rate of awareness was relatively low in study population. Thus, effective working guidelines and educational program to prevent scrub typhus must be developed, and publicity activities about the prevention of scrub typhus are needed for high-risk groups.

• Journal of Microbiology
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• v.41 no.3
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• pp.266-270
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• 2003

Orientia tsutsugamushi, an obligate intracellular bacterium, is the causative agent of scrub typhus which is histopathologically characterized by inflammatory manifestations. To understand the pathogenesis of scrub typhus, chemokine gene expression in mice after infection with O. tsutsugamushi was investigated. The mRNAs that were upregulated included macrophage inflammatory proteins 1${\alpha}$/${\beta}$ (MIP-1${\alpha}$/${\beta}$), MIP-2, monocyte chemoattractant protein 1, RANTES (regulated upon activation, normal T-cell expressed and secreted), and gamma-interferon-inducible protein 10. Peak expression of these chemokines was observed six days after infection. These responses returned to or approached baseline preinfection levels by eight days after infection. Chemokine profiles in infected mice were well correlated with the kinetics of inflammatory cell infiltration. Thus, O. tsutsugamushi appears to be a strong inducer of chemokines which may significantly contribute to the inflammation observed in scrub typhus by attracting and activating phagocytic leukocytes.

• Clinical Pain
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• v.18 no.2
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• pp.111-114
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• 2019

Guillain-Barre syndrome (GBS) is usually characterized by acute areflexic ascending paralysis with minimal sensory involvement. Only a few cases of GBS associated with scrub typhus have been reported. Previous case reports focused on the laboratory findings, pathogenesis, and clinical manifestation. Unlike the previous case, neuropathic pain was a prominent symptom of GBS in our case. We report scrub-typhus-related GBS with a detailed description of the clinical manifestations, especially neuropathic pain, along with results of serial follow-up electrodiagnostic studies.

• Korean Journal of Veterinary Service
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• v.26 no.3
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• pp.203-214
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• 2003

Scrub typhus and murine typhus are common endemic febrile illness in the fall in Korea. Scrub typhus is caused by Orientia tsutsugomushi, murine typhus is caused by Rickettsia typhi. Trombiculid mites are known as both the vector and the reservoir host of O tsutsugamushi, the mites which transmit O tsutsugomushi have been reported to be Leptotrombidium pallidum and L scutellare. The author carried out an epidemiological study of scrub typhus and murine typhus in Kyodong-Myeon, Kanghwa-Gun, Incheon in relation to the residents and the host rodents, such as their distribution, seroepidemiology, and population density of chigger mites. 1. Out of 900 residents, 33(3.7%) showed positive reaction to O tsutsugamushi, 24(2.7%) to R typhi. 2. In the seropositives to O tsutsugamushi or R typhi, between the sixties and the seventies of the age were dominant. 3. In the seropositives to O tsutsugamushi serotypically Gilliam was dominant. 4. Among the total 42 field rodents trapped by the sherman traps, 18 rodents were Apodemus agrarius(42.9%), 13 rodents were Crocidura lasiura(31.0%), 5 rodents were Musmusculus(11.9%), 2 rodents(4.8%) were Crocidura suaveolens, Rattus norvegicus, Tscherskia triton, respectively. 5. Out of 42 field rodents, 25 were parasitized by 4,419 chigger mites, showing 59.5% of the infestation rate and 98.8 of the chigger index. L pallidum parasitized in A agrarius, C lasiura, M musculus, R norvegicus and T triton, and L scutellare parasitized only C lasiura. 6. Antibodies in the sera of field rodents against O tsutsugamushi and R typhi were investigated by indirect immunofluorescent antibody technique. Positive rate of antibody against O tsutsugamushi were 11.9(5 of 42) and all of the positive is A agrarius. Antibody against R typhi was not detected. These results might provide the basic information for the management of scrub typhus and murine typhus in Kyodong-myeon, where the epidemiological studies on scrub typhus and murine typhus was not carried out enough.