[West Nile virus infection of agricultural animals in the Astrakhan region, as evidenced by the 2001-2004 serological surveys].

Sera sampled from 2,884 farming animals in the Astrakhan region in 2001 to 2004 were investigated by the hemagglutination inhibition test (HIT) in order to indicate specific antibodies to West Nile virus (WNV). HIT-positive samples were investigated by the neutralization test (NT). WNV antibodies were detected in all the examined species of animals: horses (the proportion of positive tests throughout the observation averaged 9.

[Screening of birds in the Volga delta (Astrakhan region, 2001) for the West Nile virus by reverse transcription-polymerase chain reaction].

Infection of birds, residing in the Volga lower and middle delta, with West Nile Virus (WNV) genome was detected by the RT-PCR method. A total of 315 samples of bird organs, collected in the Astrakhan region in August 2001, were examined. Positive results, with various severity degrees, were found in coots (15.

[Isolation of the West Nile fever virus from the great cormorant Phalacrocorax carbo, the crow Corvus corone, and Hyalomma marginatum ticks associated with them in natural and synanthroic biocenosis in the Volga delta (Astrakhan region, 2001)].

Four strains identified as West Nile fever virus by inhibited hemagglutination and neutralization tests, enzyme immunoassay, and reverse transcription polymerase chain reaction were isolated during a virological examination of birds and their collected ticks in the natural and synanthropic biocenoses of the Volga delta. The strains were isolated from the great cormorant (Phalacrocorax carbo), the crow (Corvus corone) and its collected Hyalomma marginatum nymphs. The types of interpopulational relations in the ecological system wild-birds-virus-mosquitoes-synanthroic birds-ticks are discussed.