Dynamics of hantavirus infections in humans and animals in Wuhan city, Hubei, China.

Hemorrhagic fever with renal syndrome (HFRS) has been a significant public problem since the first cases were reported in 1961 in Wuhan city (capital of Hubei province of China). Epidemiological surveys were carried out to better understand the dynamics of hantavirus infection in humans and animals in Wuhan. During 1961-2011, a total of 21,820 HFRS cases were registered in Wuhan. The two large epidemics had occurred during 1970-1991. They reached peaks in 1973 and 1983, respectively. There have been <10 cases since 2005. The disease occurred in the whole region including the downtown areas, but mainly in two districts. Although in 1980s and 1990s HFRS cases mainly recorded in August and winter, since 2000 the disease has mainly occurred in spring and summer. In this study, hantaviruses were identified in Apodemus mice, Rattus rats, and Mus mice by indirect immunofluorescent-assay and RT-PCR. Serological and genetic analyses showed that Hantaan virus (HTNV) and Seoul virus (SEOV) co-circulated in rodents. Phylogenetic analysis of hantaviral genome sequences revealed a novel genetic lineage of HTNV circulating in rodents in Wuhan. Another lineage of HTNV was closely related to the lineages from the provinces located in the origin and delta of Yangtze River. Remarkably, SEOV variants identified in Wuhan were more closely related to the variants found outside China. Results of the present study showed that HFRS cases in Wuhan are caused by HTNV and SEOV. Phylogenetic analysis of the hantavirus sequences revealed that a novel genetic lineage of HTNV is present in rodents in Wuhan.