Six acute serum samples that tested positive for the novel bunyavirus by specific RT-PCR were inoculated onto Vero E6 cells, and four virus strains were isolated. The initial CPE analysis showed rounded refractile cells 2-4 days after inoculation. CPE did not progress in the initial cultures, but appeared slightly at 24 hours in subsequent passages (Figure 2A) . RT-PCR revealed the presence of RNA for the novel bunyavirus in all four virus strains, and all isolates reacted with the serum of a convalescent patient in IFA ( Figure 2C ). In addition, electron microscopy showed the presence of virus particles approximately 80-90 nm in diameter-a size compatible with a bunyavirus (Figure 3 ). Virus particles were presumably localized to the Golgi apparatus ( Figure 3 ).