Seropositive rate of Orientia tsutsugamushi in Tamias sibiricus from Korea

Among wild chipmunks, Tamias sibiricus, captured in Kyunggi and Kangwon province in Korea, 1997, seropositivity for Orientia tsutsugamushi was determined. Serological test for Orientia tsutsugamushi infection was performed using indirect immunofluorescent antibody technique (IFA). Of 243 wild chipmunks, 61 against Gilliam strain and 64 against Karp strain of Orientia tsutsugamushi were IFA positive. Seropositivity against Gilliam strain was shown 33.3% in Kyunggi and 23.5% in Kangwon province, and against Karp strain was shown 33.3% and 25.4%, respectively.

Isolation of Apodemus peninsulae-borne Hantavirus and Cimparison of Molecular Biological Characteristics

Two distinct hantaviruses have been isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. Since our serosurveys conducted in 1994, a genetically distinct hantavirus from Apodemus peninsulae has been investigated. To isolate hantavirus from A. peninsulae captured in Korea, the lung homogenate of seropositive A. peninsulae inoculted Vero E6 cells. Viral antigen was detected in a progressively higher percentage of cells with subsequent passage after 80 days postinoculation. The new isolate from seropositive Apodemus peninsulae was designated Suchong virus after Suchong valley located in northeastern region of South Korea. Comparing with hantaan virus 76-118 strain, Suchong virus-1, 2, 3 and 4 showed the similarity of 71.0~91.8% at nucleotide and 90.9~94.8% at amino acid sequences in 231 nucleotides region of M segment, and the similarity of 75.1~81.0% at nucleotide and 97.5~100% at amino acid sequences in 237 nucleotides of S segment.

Serological Study on Rickettsial Infection of Wild Rodents in Kyunggi and Kangwon Provinces in Korea / 감염

BACKGROUND: This study was designed to determine the seropositivity for rickettsial infection among wild rodents captured in farms of Kyunggi province and in mountains of Kangwon province in Korea. METHODS: A total of 513 wild rodents of 5 species were captured in 1997~1998. Serological evidence for rickettsial infection was obtained using Orientia tsutsugamushi antigens by indirect immunofluorescent antibody technique(IFA). RESULTS: 168 Apodemus agrarius, 35 Microtus fortis, 3 Micromis minutus and 2 Eothenomys regulus were captured in Kyunggi province, of which 32 Apodemusagrarius, 4 Microtus fortis, 1 Micromis minutus were IF antibody positive against O. tsutsugamushi. 196 Apodemus agrarius, 77 Apodemus peninsulae and 29 Eothenomys regulus were captured in Kangwon province, of which 4 Apodemus agrarius and 5 Apodemus peninsulae were positive. CONCLUSION: Seropositivity rate against O. tsutsugamushi of wild rodents captured in Kyunggi and Kangwon provinces were 19.6% and 3.0% by IFA tests, respectively.