Objective: Five yeast-expressed recombination nucleotide proteins of European hantaviruses were prepared as coated antigens to detect hantavirus-specific antibodies in sera from hemorrhagic fever with renal syndromes (HFRS) in Hubei province, through ELISA assay. The relativity among hantaviruses prevailing in different areas was investigated.
Methods: 34 pairs of acute/convalescent serum samples were collected from HFRS patients in Hubei during 1985-1989 and 1996-2000. ELISA assay was performed to detect the reactivity of these sera to different hantavirus-recombinant nucleocapsid proteins (HV-rNP) which were derived from puumala virus (PUUV), dobrava virus (DOBV) while using hantaan virus (HTNV) to serve as control. Qualitative results were used to analyze the detection rate and thequantitative results of optical density values were used to investigate the antibodies' level and the changes.
Results: The detective efficiency of rNP against IgG antibody in samples was as follows: HTNV-rNP > DOBV-rNP > PUUV-rNP. As to the detection of IgA, it was: DOBV-rNP > HTNV-rNP > PUUV-rNP. However, there was no difference between DOBV-rNP and HTNV-rNP when the hantavirus-specific IgM was detected. PUUV-rNP showed a very weak reactivity to all the antibodies in samples, but 3-pair samples reacted strongly to all the three subtype-rNP of PUUV. Results from quantitative analysis revealed that there was a relative higher level of IgM and IgA in acute phase sera. No significant difference between IgM and IgA levels was found and the level of IgG was low. A high level of IgA was detected in convalescent sera. Moreover, the level of IgA and IgG significantly increased with the progress of the disease.
Conclusion: DOBV-rNP had a high detective efficiency to serum samples from HFRS patients in Hubei. HV-specific IgA was kept on a high level in acute and convalescent phases and had important implications for the surveillance of HFRS. Also, it is assumed that PUUV and DOBV might have existed in Hubei province.