Neutralizing antibodies to Severe Fever with Thrombocytopenia Syndrome Virus in general population, Shandong Province, China.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus (SFTSV) in East Asia. The research on seroprevalence of SFTSV in healthy people and risk factors had been detailed. However, the levels of neutralizing antibodies against SFTSV in general population were currently unclear. In the present study, we tested 1375 healthy persons from Penglai County, eastern China, for SFTSV neutralizing antibodies; 0.58% (8/1,375) was positive and the positive rates were not significantly different among people at different age groups, occupations and genders. Besides, a follow-up study was conducted and the titer of neutralizing antibodies decreased over time in all eight people but one, and the neutralizing antibodies of five lasted for the entire study period of seven years. Our results suggesting that subclinical infection or a relatively mild form of SFTS illness is occurring in this population, but a small percentage of sera have neutralizing capacity to SFTSV. Hence, most people are just susceptible to SFTSV infection.