Molecular epidemiology of hantavirus isolated from rodent hosts in Jinzhou city

Objective To study the composition of rodent species,hantavirus(HV)infection rate of the rodents,and types of hantaviruses isolated from the rodents in Jinzhou city of Liaoning province.Methods HV antigens in the rat lungs were detected with immunofluorescence assay.Partial M segment sequences were amplified with reverse transcription-polymerase chain reaction(RT-PCR)and then sequenced.The phylogenetic trees were constructed by maximum likeliood method to detect the genetic characteristics of HV.Results From 2008 to 2013,1 838 host rodents of 2 families,4 genera,and 5 species were captured in the areas with hemorrhagic fever epidemics;the average HV infection rate of the rodents was 4.24%and a statistically significant difference in the annual infection rate was observed(χ²=13.579,P<0.05).Partial M segment sequences were recovered using Seoul virus(SEOV)specific primers from 11 positive samples.The nucleotide homology of these M segment sequences ranged from 96.2% to 100% compared with SEOV and the homology ranged from 70.6% to 71.2% compared with Hantaan virus(HTNV).The established phylogenetic trees indicated that all the 11 isolated viruses belonged to SEOV and the strains showed the nearest relationship with BjHD01.Conclusion The dominant HV strain was SEOV in Jinzhou area,with less mutation,stable genetic type,and obvious regional clustering.