Serological Evidence of Severe Fever with Thrombocytopenia Syndrome Virus and IgM Positivity Were Identified in Healthy Residents in Vietnam

Authors

Xuan Chuong Tran
Sung Hye Kim
Jeong-Eun Lee
So-Hee Kim
Su Yeon Kang
Nguyen D Binh
Pham V Duc
Phan T K Phuong
Nguyen T P Thao
Wonwoo Lee
Joon-Yong Bae
Man-Seong Park
Misun Kim
Jeong Rae Yoo
Sang Taek Heo
Kyeong Ho An
Jung Mogg Kim
Nam-Hyuk Cho
Sun-Ho Kee
Keun Hwa Lee

Publication Date

10-17-2022

Journal

Viruses

Abstract

Severe fever with thrombocytopenia syndrome (SFTS), an emerging tick-borne viral disease, is prevalent in East Asia and has also been reported in Southeast Asia since 2019. SFTS patients in Vietnam were first reported in 2019. However, the seroprevalence of severe fever with thrombocytopenia syndrome virus (SFTSV) in Vietnam has not been reported. To investigate the seroprevalence of SFTSV in Vietnam, we collected serum samples from 714 healthy residents in Thua Thien Hue and Quang Nam Province, Vietnam, and the seroprevalence of SFTSV was assessed using immunofluorescence antibody assay (IFA), Enzyme-Linked Immunosorbent Assays (ELISAs) and the 50% focus reduction neutralization test (FRNT50) assay. The seroprevalence of anti-SFTSV IgM or IgG was observed to be 3.64% (26/714), high IgM positivity was >80 (0.28%, 2/714) and the titer of neutralizing antibodies against SFTSV ranged from 15.5 to 55.9. In Pakistan, SFTSV infection confirmed using a microneutralization test (MNT) assay (prevalence is 2.5%) and ELISAs showed a high seroprevalence (46.7%) of SFTSV. Hence, the seroprevalence rate in Vietnam is similar to that in Pakistan and the number of SFTS patients could increase in Vietnam.

Keywords

severe fever with thrombocytopenia syndrome virus (SFTSV), serological evidence, IgM positivity, healthy residents, Vietnam