Study of the infection of the red vole by thePuumala virus in natural foci of HFRS in Tatarstan
Introduction. Annually, the overwhelming majority of cases of hemorrhagic fever with renal syndrome (HFRS), is registered in the Volga Federal District of the Russian Federation, where the incidence rate is on average 2 times higher than in the country. In particular, the high incidence of HFRS is observed in the Republic of Tatarstan (RT), where 474 to 1076 cases were registered in 2015- 2017 years. The causative agent of HFRS in the RT is the Puumala virus (PUUV) from the genus Hantavirus, the family Bunyaviridae, whose natural reservoir is bankvole Myodesglareolus. Human become infected after close contact with carrier animal via inhaling virus contaminated aerosol, cleaning animal droppings or animal bites. Therefore, monitoring of animal infectivity and circulating strains of hantaviruses is essential to prevent infection and identify regions which are high risk of human infection. Aim. To determine the PUUV positivity of bank voles from different regions of RT captured during the spring, summer and autumn periods of 2015-2017. Materials and methods. PUUV antigens in the rodent lung tissue were analyzed using enzyme-linked immunosorbent assay. PUUV RNA was detected by RT-PCR using primer specific for the S- and M- segments of the PUUV, Tula (TULV) and Dobrava (DOBV). Results and discussion. PUUV RNA was detected in 29 out of 111 samples (26,1%) bank voles captured in 2015, while 6 animals out of 102 (7,6%) were PUUV RNA positive in 2016 and 14 samples out of 138 (10,1%) were PUUV in 2017.Summary. It is established that on the territory of the Republic of Tatarstan in various landscape-geographical zones in populations of Bank voles genetic variants of PUUV circulating. Study of lung tissue samples revealed no chantaviruses of TULV and DOBV strains. On average, the rate of infection with the PUUV virus in the red vole was high and averaged 14,16±1,81% during the observation period.