A survey on rodents infected with hantavirus and their genotypes in four counties,Yunnan Province

Objective To understand host animals and genotypes distribution of hantavirus(HV) in Yunnan Province. Methods The rodents were captured in residential and wild areas.The antigens of HV in lung tissues were detected by a direct immuno-fluorescence assay(DFA).HV RNA was detected by RT-PCR with HV genotype-specific primers. Results A total of 690 rodents of 12 species were captured in Luxi,Xundian,Yongsheng and Yulong counties,among which 304 of 6 species were captured in residential areas,with Rattus norvegicus and Rattus flavipectus as the dominant species;and 386 of 12 species were captured in wild areas,with Apodemus chevrieri as the dominant species.The total positive proportion of HV antigen in lung tissues was 4.97%(31/624).The proportion of HV confirmed in the rodents captured from residential and wild areas were 2.17%(6/277) and 7.20%(25/347),respectively.The residential rodents carrying HV were of Rattus norvegicus and Rattus flavipectus,while wild ones were Apodemus chevrieri,Eothenomys miletus,Apodemus draca and Eothenomys melanogaster.Thirty one DFA positive lung tissues were analyzed by RT-PCR and 21 samples were HV positive,of which 3 from Rattus norvegicus,Apodemus latronum and Micromys minutus belonged to Seoul type,and 18 belonged to Hantan type(2 from Rattus flavipectus,7 Apodemus chevrieri,7 Eothenomys miletus,1 Eothenomys melanogaster and 1 Micromys minutus).Conclusion In the surveillance areas,there exist not only Rattus type foci of HFRS with Rattus norvegicus as the main host,but also Apodemus foci with the main hosts:Apodemus chevrieri and Eothenomys miletus.The distribution with multi-host animals is one of the characteristics in Hantan type focus.