OBJECTIVETo understand antibody responses to and RNA sequences of Hantavirus in patients with hemorrhagic fever renal syndrome (HFRS) in Yantai areas and to demonstrate the type of the prevalent viruses caused HFRS.

METHODSSerum specimens collected at acute and convalescent stages from 90 patients with HFRS and IgM and IgG antibodies against Hantavirus were detected with ELISA, and cross plaque reduction neutralizing tests were performed to detect neutralizing antibody. Viral RNA was extracted from the patients? sera by using Trizol method and nested PCR was utilized to amplify the specific segments of the viral cDNA and the products of the PCR were TA cloned and then the nucleotide sequences were determined.

RESULTSThe IgM antibody was positive in 82.2% (88/107) of the patients while the IgG antibody was positive in 85.7% (66/77) of the patients. Both the serologic and sequence analyses demonstrated that the epidemic of HFRS in Yantai areas was caused by mixed types of Hantavirus. The prevalent strains of Hantavirus had higher homology with the strains isolated in Korea than with those isolated previously in China.

CONCLUSIONSThe serologic and sequencing analyses indicated that the epidemic of HFRS in Yantai areas was caused by mixed types of Hantavirus dominated by type SEO.