[Variants of the immunoreactivity and infectious process in bank vole (Myodes glareolus) experimentally infected with the hantavirus Puumala (PUUV)].

As a result of a longitudinal study of the Puumala hantavirus (PUUV) in the experimentally infected bank voles (Myodes glareolus), we revealed three groups of the voles differing in the immunoreactivity and viral antigen concentration in the organs. The close correlation between these parameters suggested the existence of various mechanisms of the hantavirus persistence in the host.

[Actual problems of hemorrhagic fever with renal syndrome].

From 2000 to 2011 85 600 cases of hemorrhagic fever with renal syndrome (HFRS) were registered in Russian Federation. Epidemically active foci of HFRS infection are located generally in temperate latitudes of the European part and the Far East. In the Far East regions whose fraction of all the HFRS disease cases in Russia is around 2%, the causative agents of the infection are Hantaan, Amur, Seoul hantaviruses, the natural reservoir for those are striped field mouse, Korean field mouse and brown rat. In the European part of Russia the causative agent of the infection are Puumala hantavirus as well as 2 genetic subtypes of Dobrava virus, the main reservoirs of those in the nature are bank vole, striped field mouse and Black Sea field mouse, respectively. 9 strain of Puumala and 10 strains of Dobrava virus were isolated. Based on sequencing of Dobrava virus strains significant differences were detected between Dobrava virus strains isolated from Black Sea field mouse from Sochi and striped field mouse from Lipetsk Region. Cultural inactivated vaccine against HFRS was developed and completed preclinical trials.

[The epidemiological, epizootological, and etiological characteristics of the 2006-2007 outbreak of hemorrhagic fever with renal syndrome in the Tambov Region].

The findings suggest that there are natural foci of hantavirus infection in the Tambov Region. There is evidence that Dobrava/Belgrade hantavirus (DOB-Aa) was a leading etiological agent in the outbreak of the disease in the winter of 2006-2007. Epidemiological analysis showed that the outbreak of hemorrhagic fever with renal syndrome (HFRS) afflicted the region during November to April, by reaching its peak in January (52.2%). Among the patients with HFRS, rural dwellers were 91%. People were infected with the virus mainly by taking care of domestic animals (97.2%). The reservoir of the virus and the source of its human infection in the outbreak was a field mouse, its western subspecies Apodemus agrarius agrarius, which was absolutely dominated among all the virus carriers.

[Hantavirus infection in bank voles in the natural reservoir. Part 1. Characteristics of an infection process in bank voles]. / Khantavirusnaia infektsiia u ryzhikh polevok v prirodnom ochage. Soobshchenie 1. Osobennosti infektsionnogo protsessa v organizme polevok.

The specific features of hantavirus infection in naturally infected bank voles (Clethrionomys glareolus), the principal host of hantavirus of the serotype Puumala, were studied during long-term observation of individually marked animals in the active focus of hemorrhagic fever with renal syndrome (HFRS) in the south of Udmurtia. The infection time in the bank voles was defined by paired serum seroconversion tests. In the natural focus, hantavirus was shown to cause asymptomatic persistent infection in the bank voles with the body's peak accumulation of the virus and its environmental discharge within the first month of infection. In this period the animals present the greatest epidemic and epizootic hazards. Hantavirus infection has no negative impact on the viability of bank voles.

Dynamics of Puumala hantavirus infection in naturally infected bank voles (Clethrinomys glareolus).

Specific features of hantavirus infection in bank vole (Clethrionomys glareolus) were studied in the endemic area of hemorrhagic fever with renal syndrome (HFRS) in the foothills of the Ural mountains, using long-term observations on living animals by the capture-mark-recapture (CMR) method. The results demonstrated that the infection naturally circulating in the voles is chronic (lasting for up to 15 months) and asymptomatic, with a peak of Puumala virus accumulation and release from the organism during the first month after infection. It was shown that the bank vole population includes young animals with maternal immunity, which remain resistant to the Puumala virus infection for 3-3.5 months. The infection rate in voles depended on the age and sexual maturity of animals. The greatest proportion of seropositive animals was observed among overwintered males. Seroconversion in voles was more frequent during the period of high reproductive activity.

[The disposition of natural foci of hemorrhagic fever with renal syndrome in different landscape areas of Tyumen Province]. / Razmeshchenie prirodnykh ochagov gemorragicheskoi likhoradki s pochechnym sindromom v razlichnykh landshaftnykh zonakh Tiumenskoi oblasti.

Lungs of 3159 animals of the forest complex from 90 areas of 30 administrative districts of Tyumen Province were examined by enzyme immunoassays for antigen of hemorrhagic fever with renal syndrome (HFRS) during 5 years, 1985-1989. The antigen of HERS virus was detected in the lungs of mammals of 8 species: Clethrionomys glareolus and Cl. rutilus, Siberian and Arctic lemmings (first findings in the world), M. oeconomus, field mouse, common and pygmy shrews. Nearly all the findings refer to the subzone of southern taiga and adjacent areas of subtaiga subzone where Cl. glareolus is the main reservoir of infection and Cl. rutilus an additional one. In the tundra zone, Siberian lemming is the main reservoir of infection and Arctic lemming an additional one. No natural foci of HFRS were found in forest steppe and forest tundra zones. In the subzone of the northern and middle taiga, the antigen was found only on 4 occasions: 3 in common shrews and one in Cl. glareolus (near the town of Khanty-Mansisk). An irregular annual infection rate with HFRS virus was observed in Cl. glareolus as well as its decline from spring to autumn. It cannot be ruled out that lemmings are carriers of a distinct HFRS virus serotype.

Features of circulation of hemorrhagic fever with renal syndrome (HFRS) virus among small mammals in the European U.S.S.R.

The use of indirect fluorescent antibody testing (IFAT) and enzyme linked immunosorbant assay (ELISA) procedures allowed the hemorrhagic fever with renal syndrome (HFRS) virus antigen to be detected not only in the known reservoir host, Clethrionomys glareolus, but also in 7 other species of small mammals in European foci of the U.S.S.R. Marked viscerotropism of HFRS virus and the participation of brown fat in maintaining the infection in rodents were demonstrated. The frequency of detection of circulating antigen and antibody to HFRS virus in rodents is indicative of the high level of activity of the virus in its epizootic foci.

Adaptation to laboratory and wild animals of the haemorrhagic fever with renal syndrome virus present in the foci of European U.S.S.R. Brief report.

Four strains of haemorrhagic fever with renal syndrome virus (HFRSV) from rodents or patients in European U.S.S.R. foci of HFRS were isolated in laboratory bred C. glareolus. The sensitivity of these animals to HFRSV was compared with that of five other laboratory and wild animals.