To more accurately assess the genetic relationships to known viruses, we constructed a phylogenetic tree using a neighbor-joining method [33] . The result showed that the potentially novel virus clustered with Toscana virus, Uukuniemi virus, and Rift Valley fever virus of the Phlebovirus genus ( Figure 1A ). The pools of 10 serum samples from patients and 10 serum samples from healthy subjects were also screened by PCR for the presence of the novel bunyavirus. All 10 samples from patients tested positive for the novel bunyavirus; however, all 10 samples from healthy subjects tested negative. Thus, we further focused on the virus from the family Bunyaviridae.