Identification and characterization of a novel subtype of Tula virus in Microtus arvalis obscurus voles sampled from Xinjiang, China.

Although most of Arvicolinae associated hantaviruses can not cause disease in humans, hemorrhagic fever with renal syndrome (HFRS) cases caused by Tula virus (TULV) have been described in Europe since 2002. In addition to Europe, TULV was also identified in the Microtus arvalis obscurus voles sampled from Kazakhstan, which shares borders with China. To gain more insight into the molecular epidemiology of TULV, a total of 365 rodents representing 7 species of 4 subfamily (Arvicolinae, Murinae, Gerbillinae, and Cricetinae) were captured in Qapqal county, Xinjiang, northwest China. Hantavirus RNA was recovered from 40 lung tissue samples of M. arvalis obscurus, with the prevalence of 10.96%. Genetic analysis revealed that all recovered viral sequences were most closely related to those of TULV, but exhibited >11% nucleotide differences from all currently known TULV, suggesting that they may represent a new subtype of TULV. In the S tree, the newly identified viruses formed a distinct lineage and showed a close evolutionary relationship with those sampled from Southwestern Siberia and Kazakhstan. However, they exhibited a different clustering pattern in both the M and the L trees, suggesting the possibility of genetic reassortment. Finally, the recombination event was also observed in Xinjiang TULV viruses. In sum, all these data reveal a complex evolutionary history of TULV in Central Asia.