Experimental infection of North American birds with the New York 1999 strain of West Nile virus.
To evaluate transmission dynamics, we exposed 25 bird species to West Nile virus (WNV) by infectious mosquito bite. We monitored viremia titers, clinical outcome, WNV shedding (cloacal and oral), seroconversion, virus persistence in organs, and susceptibility to oral and contact transmission. Passeriform and charadriiform birds were more reservoir competent (a derivation of viremia data) than other species tested. The five most competent species were passerines: Blue Jay (Cyanocitta cristata), Common Grackle (Quiscalus quiscula), House Finch (Carpodacus mexicanus), American Crow (Corvus brachyrhynchos), and House Sparrow (Passer domesticus). Death occurred in eight species. Cloacal shedding of WNV was observed in 17 of 24 species, and oral shedding in 12 of 14 species. We observed contact transmission among four species and oral in five species. Persistent WNV infections were found in tissues of 16 surviving birds. Our observations shed light on transmission ecology of WNV and will benefit surveillance and control programs.
Komar
Nicholas
N
Centers for Disease Control and Prevention, Fort Collins, Colorado 80522, USA. nck6@cdc.gov
Langevin
Stanley
S
Hinten
Steven
S
Nemeth
Nicole
N
Edwards
Eric
E
Hettler
Danielle
D
Davis
Brent
B
Bowen
Richard
R
Bunning
Michel
M
D000818:Animals; D001717:Birds; D003465:Culex; D005260:Female; D008297:Male; D013045:Species Specificity; D019562:Viral Load; D014901:West Nile Fever / Q000503:physiopathology / Q000635:transmission*; D014902:West Nile virus / Q000302:isolation & purification*