[Complex environmental and virological monitoring in the Primorye Territory in 2003-2006].

The paper presents the results of monitoring of viruses of Western Nile (WN), Japanese encephalitis (JE), tick-borne encephalitis (TBE), Geta, Influenza A, as well as avian paramicroviruses type I (virus of Newcastle disease (ND)) and type 6 (APMV-6) in the Primorye Territory in 2003-2006. Totally throughout the period, specific antibodies to the viruses were detected by neutralization test in wild birds (7.3%, WN; 8.0%, Geta; 0.7% Batai; 2.8%, Alpine hare (Lepus timidus); by hemagglutination-inhibition test in cattle (11.4% WN; 5.9%, JE; j 3.0%, TBE; 11.6%, Geta), horses (6.1, 6.8, 0, and 25.3%, respectively), and pigs (5.4, 1.5, 0, and 5.9%, respectively) by enzyme immunoassay (IgG) in human beings (0.8, 0.5, 6.8, and 3.2%, respectively. Reverse-transcription polymerase chain reaction (RT-PCR) was used to reveal RNA of the NP segment of influenza A virus in 57.9 and 65% of the cloacal swabs from wild and domestic birds, respectively; and the HA-segment of subtype HH was not detected in 2005. HA/H5 RNA was recorded in 5.5 and 6.7% of the swabs from wild and domestic birds, respectively; 6% of the specimens from domestic birds were M-segment positive in 2006. RNA of influenza A virus NA/H7 and RNA was not detected throughout the years. In 2004, the cloacal swabs 8 isolated influenza A strains: two H3N8 and two H4N8 strains from European teals (Anas crecca), two (H3N8 and H6N2) strains from Baikal teals (A. formosa), one (H10N4) strain from shovelers (A. clypeata), and one (H4N8) from garganeys (A. querquedula). In 2004, one ND virus strain was isolated from the cloacal swabs from European teals (A. crecca). RT-PCR revealed RNA of this virus in some 8 more cloacal swabs from black ducks (A. poecilorhyncha) (3 positive specimens), pheasants (Phasianus colchicus) (n = 2), garganeys (A. querquedula) (n = 1), gadwalls (A. strepera) (n = 1), and geese (Anser anser domesticus) (n = 1). Sequencing of the 374-member fragment of the ND virus F gene, which included a proteolytic cleavage site, could assign two samples to the weakly pathogenetic variants of genotype 1, one sample to highly pathogenic variants of genotype 3a, five to highly pathogenic ones of genotype 5b. Isolation of APMV-6 (2003) from common egrets (Egretta alba) and geese (Ans. anser domesticus) is first described.

[Detection of the circulation of Crimean-Congo hemorrhagic fever virus in the piedmont steppes of the North Caucasus].

The laboratory verified cases of Crimean-Congo hemorrhagic fever (CCHF) in the piedmont steppes of the North Caucasus (Malgobeksky District, Republic of Ingushetia) are first described. The source of the first infection was Ixodidae ticks; three subsequent sources were contacts with the bloody discharges from patients. CCHF virus genome was detected in the blood of the cattle from an epidemic focus and in the pools of the Ixodes ticks Haemaphysalis parva Neum., 1897 and Boophilus annulatus Say, 1821, taken from cattle. The problem of including the piedmont steppes of the North Caucasus into the CCHF nosological area is discussed.

[Khurdun virus, a presumably new RNA-containing virus associated with coots (Fulica atra), isolated in the Volga river delta].

The prototype strain LEIV-Ast 01-5 of the unclassified enveloped RNA-containing Khurdun virus, less than 220 nm in size, which is widely distributed among coots (Fulica atra) in the Volga River delta, was deposited on November 4, 2004, at the State Virus Collection (SVC # 992). The virus was isolated annually (2001-2004) with a frequency of 2.3-8.5% (mean 6.3%) when examining 348 coots caught in the lower and middle zones of the Volga River delta. Virological examinations used mixed pools of the brain and spleen to inoculate neonatal albino mice and the cellular line Vero-E6. One strain was isolated from a pygmy cormorant (Phalacrocorax pygmaeus). The virus could not be isolated from other species of 1080 birds, 20 hares, 140,000 mosquitoes of 5 predominant species, and 6,700 Hyalomma marginatum ticks. Any antigenic relationship of the virus with all the viruses early isolated in the Northern Caspian Sea region has not been found. ELISA has been developed to detect and identify Khurdun virus antigen.

[Circulation of West Nile virus (Flaviviridae, Flavivirus) and some other arboviruses in the ecosystems of Volga delta, Volga-Akhtuba flood-lands and adjoining arid regions (2000-2002)]. / Osobennosti tsirkuliatsii virusa Zapadnogo Nila (Flaviviridae, Flavivirus) i nekotorykh drugikh arbovirusov v ékosistemakh del'ty Volgi, Volgo-Akhtubinskoi poimy i sopredel'nykh aridnykh landshaftakh (2000-2002 gg.).

Comprehensive virological, serological as well as genetic studies of the ecology of West Nile Virus (WNV) as well as of some other arboviruses were undertaken in different ecosystems in the territories of the Astrakhan Region and of the Kalmyk Republic. The main carriers (mosquitoes, ticks, birds and mammals) were defined as involved in the circulation of viruses within the natural and anthropogenic biocenosis. Phylogenetic examinations of isolated strains and samples, which were positive in RT-PCR, showed an absolute predominance of genotype I virus that was most closely related to American and Israeli strains. At the same time, epidemic strains had up to 6% of nucleotide differences versus the historic strains isolated in the same region 20-30 years ago. Besides, the circulation of genotype IV was discovered; it was characterized by a lower pathogenicity, which, possibly, ensures the shaping of a pronounced immune interlayer bearing no epidemic consequences. An analysis of the study results on the WNV ecology denotes the epicenter of the endemic territory located in the middle part of the Volga delta.

West Nile virus and other zoonotic viruses in Russia: examples of emerging-reemerging situations.

Studies of the interactions of vertebrates, viruses and arthropod vectors of these viruses were monitored in terms of different ecological groups of viruses transmitted by mosquitoes and ticks in Northern Eurasia in an area encompassing more than 15 million km2. About 90 viruses were isolated, including 24 new to science. Newly recognized infections of vertebrates, including humans, were described. Many unusual epidemic situations were analysed. Permanent efforts were established to prevent bioterrorist activities and their consequences. Extensive epidemic outbreaks of West Nile fever (WNF; i.e., fever caused by West Nile virus) and Crimean-Congo hemorrhagic fever (CCHF) with unusual high mortality appeared in the last four years in southern Russia. We determined infection rates in humans, domestic and wild animals, mosquitoes and ticks from natural and synanthropic biocenoses [Editorial note: "synanthropic" means, roughly, all species living with (c.f. lice, fleas) or near people, such as in houses (c.f. house mice), parks (c.f. Rattus spp.), and the like, rather like "peridomestic", but not strictly so; "biocenosis" is the biome, the "totality of living populations in a particular habitat, which itself is only a part of the ecosystem".]. CCHF virus strains were phylogenetically similar to strains isolated in this area 35 years ago but different from Central-South-Asian and African strains. Before the outset of the current emergence of epidemic WNF, three genetic variants of this virus had been isolated in USSR, two African and one Indian. Phylogenetic analysis of complete genome sequences of epidemic strains demonstrated considerable similarity to strains from USA and Israel and differences from strains isolated in the same USSR areas 20-30 years before. In addition to strains of genotype 1, we isolated strains of second and third lineages and a strain of a fourth genetic variant. Nucleotide differences of these strains from all three genotypes was about 30%. The emerging WNF situation in Russia for the last 4 years probably has been the result of not only natural and social factors, but also to introduction of more virulent strains or by evolution of the virus.

[ West Nile fever among residents of the Astrakhan region in 2002]. / Zabolevaemost' i zarazhaemost' naseleniia Astrakhanskoi oblasti likhoradkoi Zapadnogo Nila v 2002 g.

Thirty-three persons infected with West Nile fever were detected in 2002 in the Astrakhan Region; the diagnosis was confirmed serologically and the maximal number of the infected was registered in August, same year. The indices of the specific humoral immunity varied from 3.3% to 27.1%. A monitoring determined the highest infection risk among the residents of the Volga middle delta.

[Characteristics of Crimean-Congo hemorrhagic fever virus circulating in Russia and Central Asia]. / Kharakteristika virusa Krymskoi-Kongo gemorragicheskoi likhoradki, tsirkuliruiushchego v Rossii i respublikakh Srednei Azii.

Five antigen-positive samples isolated from patients with Crimean-Congo hemorrhagic fever (CCHF) and from Hyalomma marginatum ticks collected in the European part of Russia and three laboratory strains of CCHF isolated in Russia, Uzbekistan, and Tadjikistan were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing. Comparison of nucleotide sequences of fragments of CCHF virus genome S segment and phylogenetic analysis of Russian strains showed that all CCHF strains isolated from humans and H. marginatum circulating in Russia were closely related and differed essentially from CCHF variants from other regions. Strains isolated in Uzbekistan and Tadjikistan were most closely related to CCHF strains from China.

[Comparative evaluation of test-systems for detection of Venezuelan equine encephalomyelitis virus and variola virus using dot immunoenzyme assay and solid-phase lanthanide immunofluorescent assay]. / Sravnitel'naia otsenka test-sistem dlia opredeleniia virusov venesuél'skogo éntsefalomielita loshadei i ospovaktsiny metodami tochechnogo immunofermentnogo analiza i tverdofaznogo lantanidnogo immunofliuorestsentnogo analiza.

The sensitivity and specificity of 4 experimental test systems for dot enzyme immunoassay (dot-EIA) and solid-phase lanthanide immunofluorescent analysis (SP LIFA) were studied with Venezuelan equine encephalomyelitis (VEE) and variolovaccinia viruses. Test systems for SP LIFA proved to be 25 times more sensitive than those for dot-EIA. The test systems were highly specific and did not react with the heterologous viruses and proteins. Diagnostic agent for detecting VEE virus in dot-EIA was false-positive with Sindbis virus in low dilutions. The first trials of the Russian test systems for dot-EIA and SP LIFA showed that these systems rapidly and reliably detect VEE and variolovaccinia viruses in liquid samples.