Serological Characterization of Soochong and Muju Virus as New Serotype of Hantavirus

ABSTRACT

Apodemus agrarius, which accounts for three-fourths of the wild rodents, mainly inhabits in cultivated fields of Korea. Apodemus peninsulae and Eothenomys regulus are the second and third dominant species, respectively. Soochong virus (SOOV) from A. peninsulae and Puumala-related Muju virus (MUJV) from E. regulus were isolated in 1997 and 1998 in Korea, respectively. But serological characterizations of SOOV and MUJV were not identified clearly. Thus, in order to determine the serotypic classification, simultaneous cross-indirect immunofluorescent antibody (IFA) assay and cross-plaque reduction neutralization (PRN) test against four different hantaviruses were conducted with sera from 17 A. agrarius, 19 A. peninsulae, and 8 E. regulus strains. IFA titers of sera from A. agrarius and A. peninsulae were the highest to Hantaan virus (HTNV) and SOOV, respectively. However, most sera showed similar IFA titers to Seoul virus (SEOV). Therefore it was difficult to do serotyping using the sera from A. agrarius and A. peninsulae by IFA. In case of sera of E. regulus, IFA titers to Puumala virus (PUUV) were higher than HTNV, SOOV and SEOV. Cross-PRN result of A. agrarius to HTNV, SOOV, SEOV and PUUV was 6,890, 5,120, 110 and 30, respectively. In case of A. peninsulae, the mean PRN titer was the highest to SOOV (16,820) and those to HTNV, SEOV and PUUV were 1,580, 100 and 30, respectively. The mean PRN titers of E. regulus to HTNV, SOOV, SEOV and PUUV were 70, 10, 80 and 640. SOOV and MUJV could be distinguished from HTNV and SEOV by cross-PRNT. These results demonstrate that SOOV and MUJV could be classified as new serotype of hantavirus.