Molecular genomic characterization of tick- and human-derived severe fever with thrombocytopenia syndrome viruses isolated in South Korea

Yun Seok-Min, Park Sun-Whan, Lee Won-Ja, Lee Joo-Yeon*
Division of Emerging Infectious Disease and Vector Research, Center for Infectious Diseases Research, National Institute of Health, KCDC
Park Su-Jin, Choi Young-Ki
College of Medicine and Medical Research Institute, Chungbuk National University

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne viral disease caused by the SFTS virus (SFTSV). During entomological surveillance of SFTSV infection of Korean ticks collected in SFTS outbreak areas, we isolated one SFTS virus and designated KAGWT. In addition, we isolated three SFTSVs from patients with typical SFTS symptoms.
Methods/Results: In this study, we intended to report the complete genomic sequences of these isolates and compare the genetic and evolutionary characteristics between tick- and human-derived Korean SFTSV isolates. Genetic and phylogenetic analyses of these sequences revealed that the tick-derived Korean SFTSV strain was clustered into genotype B, the most prevalent genotype in South Korea, and was closely related to other SFTSV in the same group. Furthermore, our results show that at least four different genotypes of SFTSV strains are co-circulating in South Korea.
Conclusion: These findings provide information on regarding the molecular epidemiology, genetic diversity, and evolution of SFTSV in East Asia.

Keywords: Severe fever with thrombocytopenia syndrome virus, Tick, Human, South Korea