• Journal of the Korean Geographical Society
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• v.42 no.6
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• pp.863-878
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• 2007

The time-spatial distribution of Scrub typhus and its relationship with environmental ecology, such as climate, and habitat change are analyzed in respect of the geography of disease. Scrub typhus was firstly reported in 1951, and reemerged in 1986 mainly in southwestern Korea. later it has sharply increased and spreaded out toward whole country in 1998 and 2004, except mid-eastern mountainous region. Hwasung City is the typical example of sudden upsurge of Scrub typhus. High incidence of Scrub typhus patients might due to elevated temperature and decreased precipitation during the summer, as well as milder autumn. Sharp increase of Scrub typhus patients at rural area since 1980's might also be the result of the rapid changes of land use pattern, which eventually have contributed for the active development of dense vegetation and propagation of chigger mites around cultivated land.

• 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.

• Tuberculosis and Respiratory Diseases
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• v.70 no.3
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• pp.247-250
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• 2011

The pandemic (H1N1) 2009 influenza outbreak coincided with the typical Scrub typhus season, which can lead to diagnostic difficulties due to their similar and non-specific symptoms. Here we describe a case of laboratory confirmed co-infection of Pandemic (H1N1) 2009 influenza and Scrub typhus and discuss the difficulties in distinguishing the two illnesses clinically.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.13 no.2
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• pp.208-216
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• 2006

Purpose: This study was done to identify the differences in effectiveness of disinfections for surgical hand scrubbing according to the duration of scrubbing and the type of disinfectant. Method: From June 30 to August 14, 2003, the data were collected from 30 surgical nurses and surgeons in one general hospital in P city, Korea. All participants washed their hands with two different disinfectants and four different scrubbing times, they placed both finger tips on a blood agar plate and using sterile cotton tips microbes were collected from their palms, nails and forearms. Results: The first hypothesis of this study(with same disinfectant, there will be no difference in effect of disinfection in surgical hand scrub among four time groups) was supported. The second hypothesis of this study(with same duration of surgical hand scrub, there will be no difference in effect between two disinfectants) was also supported. Conclusion: There are no differences in effectiveness of disinfection for surgical hand scrubbing according to duration of the scrubbing and the type of disinfectant. So it is concluded that the effectiveness of disinfection depends more on the exactly how the scrubbing is done rather than the duration of scrubbing or the type of disinfectant.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.13 no.3
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• pp.359-367
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• 2006

Purpose: This study was a within subject repeated pretest-posttest design done to compare the effect of disinfection and the degree of MRSA(Methicillin- resistant staphylococcus aureus) isolation from hand disinfectant in ICU nurses. Method: Out of the total internal medicine/surgery ICU nurses at a university hospital in Seoul, 29 female nurses who were participating in direct patient care were participants in this study. After collection of samples, Staphylococcus aureus and MRSA were isolated from the palms, nails and nasal cavities of the nurses according to disinfectants (soap and beta-scrub). Results: The effect of disinfection was greater in the beta-scrub group than in the soap group, and the effect of disinfection on palms was higher in the beta-scrub group than in the soap group. As for the degree of MRSA isolation, there was more isolation in palms in the soap group than in the beta-scrub group but there was no difference in the degree of MRSA isolation from the hand disinfectant in nails and nasal cavities. Conclusion: Beta-scrub showed a superior prolonged effect against transient bacteria compared with soap. Further, to reduce MRSA infection, we recommend interventions focused on these aspects.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1728-1735
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• 2014

Scrub typhus, caused by infection with Orientia tsutsugamushi, is a mite-borne zoonotic disease endemic to the Asian-Pacific region. In Korea, the incidence of this disease has increased with climate changes, and over 10,000 cases of infection were reported in 2013. Although this infection is treatable with antibiotics such as doxycycline and azithromycin, an effective prophylactic vaccine against O. tsutsugamushi would be more desirable for preventing scrub typhus in endemic areas. In this study, we investigated the 56-kDa type-specific antigen (TSA56), which is a major outer membrane protein of O. tsutsugamushi, as a vaccine candidate. Intranasal immunization of recombinant TSA56 (rec56) induced a higher level of TSA56-specific IgG than that induced by intramuscular immunization of tsa56-expressing DNA (p56). Both types of immunization induced a cell-mediated immune response to TSA56, as demonstrated by the splenic cell proliferation assay. Mice immunized with p56, followed by rec56 plus heat-labile enterotoxin B subunit from E. coli, had a stronger protection from a homologous challenge with the O. tsutsugamushi Boryong strain than with other combinations. Our preliminary results suggest that an effective human vaccine for scrub typhus can include either recombinant TSA56 protein or tsa56-expressing DNA, and provide the basis for further studies to optimize vaccine performance using additional antigens or different adjuvants.

• 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.

• Tuberculosis and Respiratory Diseases
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• v.52 no.3
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• pp.283-287
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• 2002

Scrub typhus is an acute, febrile disease of humans that is caused by Orientia Tsutsugamushi. It is transmitted through the bite of chiggers. The spectrum of the clinical severity for scrub typhus ranges from mild to severe with fatal complication such as meningoencephalitis, pneumonitis, myocarditis. Severe pulmonary involvement e.g. acute respiratory distress syndrome(ARDS) and meningoencephalitis have rarely been observed since the introduction of specific antibiotic therapy. We experienced a case of scrub typhus manifested with ARDS and meningoencephalitis. The patient was treated with doxycycline, anticonvulsant and mechanical ventilator therapy.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.327-331
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• 2012

Monthly surveys were conducted to investigate the occurrence of chigger mites and seroprevalence of scrub typhus among small mammals in Jeollanam-do, the southwestern part of Korea, from November 2006 through October 2007. Fifty-eight small mammals, including 57 Apodemus agrarius (98.3%) and 1 Crocidura lasiura (1.7%), were captured, and a total of 4,675 chigger mites representing 4 genera and 8 species were collected from them. The chigger infestation rate among small mammals was 69.0%. The most predominant species in A. agrarius was Leptotrombidium scutellare (54.0%), followed by Leptotrombidium pallidum (39.4%), Leptotrombidium orientale (4.4%), Leptotrombidium palpale (1.1%), Neotrombicula tamiyai (0.6%), Eushoengastia koreaensis (0.3%), Neotrombicula gardellai (0.3%), and Cheladonta ikaoensis (<0.1%). The chigger index of A. agrarius was the highest in October (740.0), followed by November (242.0), September (134.6), March (98.3), February (38.2), January (35.3), December (34.5), April (30.8), and May (1.7). The average antibody positive rate of scrub typhus in wild rodents was 50.0%. The seropositive rates were high in October (100.0%) and November (83.3%), whereas those in other months were relatively low (28.6-57.1%). The chigger index of L. scutellare rapidly increased in September to form an acuminate peak in October, followed by a gradual decline. These results suggest that the outbreak of scrub typhus in the southwestern part of Korean peninsula is mostly due to L. scutellare.

• Parasites, Hosts and Diseases
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• v.47 no.4
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• pp.381-386
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• 2009

A survey to determine the geographical distribution and relative abundance of potential vectors of scrub typhus was conducted from October to November 2006 at 13 localities throughout the Republic of Korea. Apodemus agrarius accounted for 97.6% (80/82) of all rodents, while only 2 Myodes regulus (2/82) were collected. A total of 10,860 chiggers were collected from A. agrarius belonging to 4 genera and 8 species, while only Walehia fragilis (40) was collected from Myodes regulus. Leptotrombidium pallidum (8,137; 74.9%), a vector of scrub typhus, was the predominant species collected from A. agrarius followed by Leptotrombidium scutellare (2,057, 18.9%), Leptotrombidium palpale (279; 2.7%), Leptotrombidium orientale (232; 2.1%), and Leptotrombidium zetum (79; 0.7%), Neotrombicula tamiyai (58; 0.5%), Euschoengastica koreaensis (16; 0.1%), and Cheladonta ikaoensis (2; < 0.1 %). L. pallidum was the predominant chigger collected at collection sites in Gangwon (100%), Gyeonggi (87.2%), Chungnam (100%), Chungbuk (100%), Jeonbuk (73.9%), Jeonnam (77.0%), and Gyeongbuk (66.1%) provinces, whereas L. scutellare was the predominant chigger collected in Gyeongnam province (77.9%) and Jeju Island (62.3%). Data suggest a correlation between chigger population abundance and human cases of scrub typhus in Korea.