Seroprevalence of severe fever with thrombocytopenia syndrome virus in animals in Kagoshima Prefecture, Japan, and development of Gaussia luciferase immunoprecipitation system to detect specific IgG antibodies.

We conducted a seroprevalence investigation of the healthy population of animals in Kagoshima Prefecture, an area in which severe fever with thrombocytopenia syndrome (SFTS) is endemic. Of 104 domestic cat and 114 dog samples, 2 (1.9%) and 11 (9.6%) were positive for anti-SFTS virus (SFTSV) IgG by indirect ELISA, respectively. Viral RNA was detected in one dog (0.9%) by RT-PCR. Of the 102 wild boar (Sus scrofa) and 107 deer (Cervus nippon) samples tested, 55 (53.9%) and 37 (34.7%) were positive for anti-SFTSV IgG, respectively. Only one wild boar (1.0%) was positive for viral RNA. Although symptomatic SFTSV infections in domestic cats have increased in this area, the seroprevalence of the healthy population of domestic cats tends to be lower than those of other animals. We developed a Gaussia luciferase immunoprecipitation system (GLIPS) using mammalian cells expressing a recombinant SFTSV nucleoprotein (SFTSV-rNP) for the detection of SFTSV-specific antibodies in samples from various animal species. The sensitivity of the assay was highly consistent with that of indirect ELISA, indicating that it could serve as a useful tool for a large-scale surveillance of SFTSV across multiple species of animals.