The Role of Birds as Potential Reservoirs of West Nile Virus in the Territory of the Russian Federation

Abstract

Submitted are the materials on epizootiology of West Nile Fever in birds, taking into account their migration. Described are the characteristics of WNF in wild and synanthropic birds. Ecological relationships between birds, mosquitoes, ticks and West Nile virus are analyzed. Main autumn bird migratory directions are characterized and the data on WNF monitoring in birds in different geographical regions of Russia are presented.

Spatial patterns of West Nile virus distribution in the Volgograd region of Russia, a territory with long-existing foci

“…In addition, the Volga-Akhtuba floodplain can be considered a zone of transfer of virus from the delta areas of the neighbouring Astrakhan region and other territories [ 111 ]. The Volga delta is located along one of the main seasonal European-Asiatic avian migration routes ( http://www.seen-net.eu ), and its wetlands are favorable for nesting [ 27 ]. Out of 229 bird species recorded from this area, 227 species migrate to winter localities in Africa, the Indian subcontinent, and the Mediterranean [ 112 ] which are WNV-endemic areas.…”

“…Dead bird occurrences might be correlated with human WNV risk as was observed in some US studies [ 40 , 128 – 130 ]. However, massive mortality among crows only was observed during the outbreak in Volgograd in 1999 [ 25 , 27 ]. Mortality among the local species Corvus corone was not observed in the Astrakhan region despite the widespread involvement of this species in the circulation of the virus, perhaps due to long-term interaction with this virus [ 25 ].…”

“…In the natural environment, the transmission cycle involves wild birds as principal hosts and mosquitoes that feed on birds as vectors [ 26 ]. Fifty-six bird species have been involved in virus transmission in wetlands and surroundings of the Volga delta [ 27 ]. Storks and other Ciconiiformes were most frequently identified as a virus host among wild birds as well as the great cormorant ( Phalacrocorax carbo ), Eurasian coot ( Fulica atra ), common moorhen ( Gallinula chloropus ), great crested grebe ( Podiceps cristatus ), and seagull and sterna (family Laridae) (based on virus detection among wild birds) [ 27 , 28 ].…”

“…Fifty-six bird species have been involved in virus transmission in wetlands and surroundings of the Volga delta [ 27 ]. Storks and other Ciconiiformes were most frequently identified as a virus host among wild birds as well as the great cormorant ( Phalacrocorax carbo ), Eurasian coot ( Fulica atra ), common moorhen ( Gallinula chloropus ), great crested grebe ( Podiceps cristatus ), and seagull and sterna (family Laridae) (based on virus detection among wild birds) [ 27 , 28 ]. Synanthropic birds, primarily rooks, crows, pigeons, and sparrows, have been involved in the transmission cycle in urban areas [ 29 , 30 ].…”