Figure 4.
Time course of serum viral RNA and neutralizing antibodies in 17 sheep positive for severe fever with thrombocytopenia syndrome virus RNA, China. Detection of virus specific antibodies in Laizhou and Penglai is indicated by the dashed line and the bold line, respectively. The numbers on the lines indicate viral RNA copies (×103/mL) in serum samples detected on the indicated dates. Neutralizing antibody levels in the initial samples collected on June 21, 2011, in the samples positive for viral RNA, and in the samples collected at the late stage on October 20, were measured by using a microneutralization assay. Neutralizing antibody titers are shown with different symbols: *neutralizing antibodies not detected; †neutralizing antibody titers = 4; ‡neutralizing antibody titers = 16; §neutralizing antibody titers >64.