[Investigation on hantaviruses infection in rodents from free markets in Beijing areas].

OBJECTIVE

In order to find out the factors related to hemorrhagic fever with renal syndrome (HFRS) infection, and to evaluate the probability of ecdemic hantaviruses (HV) infection in rodents in Beijing areas.

METHODS

Rodents were collected in a large-scale railway station and a produce market with 'trap nights' method from April to May, 2004. The IgG reacting sera to HV antigen were detected using ELISA. The partial M and S segment of HV from captured rodent lung samples were amplified with RT-PCR. The PCR products were purified and sequenced. BLAST program was then used to perform on nucleotide pairwise alignment with all available sequence in GenBank. The alignment of the multiply nucleotide and the deduced amino acid sequences, together with phylogenetic analysis were completed with DNASTAR software.

RESULTS

The average population density was 3.49% (24/690). The overall seroprevalence of HV infection was 8.3% (2/24). RT-PCR positive rates were 8.3% (2/24). The nucleotide sequences of 356 bp region (1958 - 2313) of M segment obtained from 2 samples were all identified to Seoul virus (SEOV), with 7.6% heterogeneity. The dc501 strain from railway station was closely related to SD227 and Hebei4 from Shandong and Hebei provinces respectively. BjFT01 strain from the farm product market had more special nucleotide transitional mutations than other known SEOV from Beijing in GenBank. This strain, together with known HN71 from Hainan province, K24-E7 from Zhejiang province, L99 from Jiangxi province and R22 from Henan province, represented a monophylogentic linkage.

CONCLUSION

The higher HV prevalence of rodents in transportation center was the potential and important risk for HFRS epidemic in Beijing. The increasing prevalence of M. musculus should call for attention. It was possible that SEOV in Beijing was imported by infected rodents through vehicles from other provinces.