[A ten-year retrospective investigation of serum against EHF antibodies in Nanchong District, Sichuan].

This paper reports a retrospective inquiry of blood serum against epidemic hemorrhagic fever (EHF) antibodies in some of our hospital treated EHF patients during 1974-1984. It was found that the total positive rate of sera against EHF antibodies obtained from different periods of EHF patients was 86.8% (170/196). The titers were highest in patients who had been attacked within one year and the titers markedly decreased from the second year onwards. However certain level of serum titre could be detected up to 8th-10th year after the acute infection. Normal persons in high-incidence districts and medical workers who had kept in close contact for many years with EHF patients were found to be negative. It is presumed that this disease's latent infection is probably very low.