[The epizootological and virological characteristics of a natural hantavirus infection focus in the subtropic zone of the Krasnodarsk Territory].

A natural focus of hantavirus infection was detected and examined during the studies conducted in 2000-2002 around the Sochi (the western spurs of the Great Caucasus Ridge, which descended to the Black Sea (the Krasnodar Territory of Russia). At least 4 rodent species, such as Microtus majori, A. (S.) ponticus, A. agrarius, A. (S.) ciscaucasicus, were shown to participate in the circulation of hantaviruses. A comparative analysis of the nucleotide sequences of genomic S- and M-segments of hantaviruses has provided evidence that 13 viral RNA isolates from the A. (S.) ciscaucasicus belong to the Dobrava/Belgrade virus clade; however the RNA isolate from the Microtus majori belong to the Tula virus clade.

[Hantaviruses and hantavirus infections]. / Khantavirusy i khantavirusnye infektsii.

Hemorrhagic fever with renal syndrome (HVRS) has been for decades a topical problem for healthcare systems of many countries in the Eurasian continent. Viruses triggering HVRS alongside with other related viruses (but not pathogenic to man) were discovered in 70-80-ies and formed a new genus Hantavirus of the Bunyaviridae family. The study results of a severe outbreak of the respiratory disease with the mortality rate of 60% (South-West of the USA, 1933) showed that hantaviruses were also among the causative agents. Later, the disease was designated as hantavirus cardio-pulmonary syndrome. By now, it has been established that hantaviruses are wide spread with different rodents being their carriers. The discussed viruses cause, in rodents, a chronic asymptomatic infection and are transferred, later, to man by the aerogenic path through excretions of infected animals. Studies of hantaviruses have been restricted for a long time due to their high pathogenicity (protection equipment not below than the P-3 level is needed), because of a lack of a laboratory model of infected animals and because of a low growth in cell cultures. With the rapid development and application of molecular biological techniques of the recent years, substantial progress has been made in studies of hantaviruses. Different aspects of hantavirus ecology, molecular biology, morphology, pathogenesis and diagnostics are discussed in the offered survey.

[The spread of hantaviruses in western Siberia]. / O rasprostranenii khantavirusov v Zapadnoi Sibiri.

Studies made in west Siberia established the existence of at least 4 hantavirus types: Puumala, Tula, Topografov, and Dobrava/Belgrade. The authors detected Puumala virus genovariants in voles, Tula virus in sagebrush and narrow-skulled voles, and Topografov virus in Siberian lemmings. The etiological role of the hantavirus Dobrada/Belgrade was defined in the structure of morbidity of hemorrhagic fever with the renal syndrome. In Russia, hantaviruses were first detected in mites: a hantavirus antigen was found in one of the enzyme immunoassayed pools of the mole mites (Haemogamasus ambulans) collected from the Siberian lemming brooding burrow in the near-floodplain habitats of the transitional Yenisei tundras in southwest Taimyr.

[Outbreak of hemorrhagic fever with kidney syndrome in Egor'ev district of Moscow region]. / Analiz vspyshki gemorragicheskoi likhoradki s pochechnym sindromom v Egor'evskom raione Moskovskoi oblasti.

Epizootological, serological, and molecular virological analysis of an outbreak of hemorrhagic fever with renal syndrome (HFRS) in the Egoryevsk district of Moscow region (September 1995-January 1996) has been carried out. Hantavirus (Puumala) antigen and virus-specific antibodies were isolated from bank voles captured in the endemic focus. Anti-Puumala antibodies were detected in the sera of all HFRS patients and in 2% healthy residents of the endemic focus. Analysis of nucleotide sequence (RNA from hantavirus-positive lung of a bank vole) showed that the studied hantavirus is a distinct genotype of Puumala virus. Hence, a new highly active natural focus of HFRS associated with Puumala virus, dangerous for the population, has been revealed in Moscow region.

[An epidemiological analysis of hemorrhagic fever with renal syndrome morbidity in the Republic of Bashkortostan in 1997]. / Epidemiologicheskii analiz zabolevaemosti gemorragicheskoi likhoradkoi s pochechnym sindromom v Respublike Bashkortostan v 1997 g.

The outbreak of hemorrhagic fever with renal syndrome (HFRS) in the Republic of Bashkortostan, resulting in 10,057 registered cases of the disease (287 cases per 100,000 of the population), was analyzed. HFRS cases among the population were registered in 52 out of 54 regions of Bashkortostan. 31% of the total number of patients were the inhabitants of rural regions (170 cases per 100,000) and 69% were urban dwellers (295 cases per 100,000), mainly in Ufa (512 cases per 100,000). HFRS morbidity among males was fourfold higher than among females. In 70% of cases persons aged 20-49 years were affected. 5% of the total number of patients were children aged up to 14 years. In 34 cases (0.4%) the severe clinical course of the disease had a fatal outcome. Cases of HFRS were registered from April 1997 till March 1998 with the highest morbidity rate observed during the period of August-December. In most cases (46.8%) both urban and rural dwellers contacted infection during a short-term stay in the forest. As the result of the serological examination of the patients, all HFRS cases were etiologically attributed to hantavirus, serotype Puumala. The main natural reservoir of this virus and the source of human infection in Bashkortostan were bank voles (Clethrionomys glareolus), the domination species among small mammals in this region.

[A system of immunoenzyme analysis using biotinylated monoclonal antibodies for typing hantavirus antigens]. / Sistema immunofermentnogo analiza s ispol'zovaniem biotinilirovannykh monoklonal'nykh antitel dlia tipirovaniia antigenov khantavirusov.

Enzyme immunoassay with biotin-labeled monoclonal antibodies to Puumala virus was used for typing hantavirus antigens. The system is type-specific, that is, it detects Puumala virus only, which was demonstrated by typing 9 hantavirus antigens in infected Vero E5 cells and by epizootological analysis of an HFRS outbreak in the Yegoryevsk district of the Moscow region in November-December 1995. The suggested system may be used as an element of EIA screening of natural samples in analysis of the screening results.

[The antigenic differentiation of hantaviruses by using monoclonal antibodies]. / Antigennaia differentsiatsiia khantavirusov s pomoshch'iu monoklonal'nykh antitel.

85 hantavirus (HV) strains from Russia and other counties were examined by indirect fluorescent antibody test using monoclonal antibodies (MAbs) prepared against hantaviruses: Hantaan (Hantaan 76-118, A-9 strains), Seoul (SR-1, R-22 strains) and Puumala (Hallnas 83-223 strain). 68 HV strains were differentiated into five virus type groups: Hantaan, Puumala, Seoul, Prospect Hill and Belgrade-Dobrava. 17 strains were found to be antigenically closely related but distinct from Hantaan type (4 strains), Puumala (6 strains) and Prospect Hill (7 strains). The antigenic characteristics of these 17 strains suggested two supplementary antigenic subgroups of the Hantaan, two of Puumala and two of Prospect Hill.

[Genetic differentiation of hantaviruses using the polymerase chain reaction and sequencing]. / Geneticheskaia differentsiatsiia khantavirusov s pomoshch'iu polimeraznoi tsepnoi reaktsii i sekvenirovaniia.

Thirty-two hantavirus strains and 8 samples of lung tissue from rodents collected in different regions of Russia have been examined by molecular biological methods. Two methodological approaches have been employed for the study of genetic relationships between the viruses: nested PCR assay and common RT-PCR with subsequent direct sequencing of 200 and 365 base pair of G2 protein encoding regions of M-segment, respectively, and the resultant sequences were compared with those of the prototype hantavirus. The study revealed a mosaic pattern of distribution of different hantavirus genotypes on the territory of Russia.