The duration of viremia patients with epidemic hemorrhagic fever.

The duration of viremia in patients with epidemic hemorrhagic fever (EHF) was studied using immunofluorescence technique and cell culture assays. The duration of virus in plasma of EHF patients was about 1 week, which was concomitant with the febrile phase of the disease. Comparatively, the separation rate of viruses in peripheral blood mononuclear cells (PBMC) was greater (1.8 times) than in plasma, while the detected peak of EHF (in 4-7 days after onset of the disease) was found to be 2 or 3 days less than that of plasma, thus the detectable viremia was prolonged until the 8th to 11th day of the disease. High titre EHF antibody of IgG, TgM was unable to neutralize the virus in human blood. The results revealed that a blood-cell-associated prolonged viremia is one of the characteristics of EHF infection.