Role of California (Callipepla californica) and Gambel's (Callipepla gambelii) quail in the ecology of mosquito-borne encephalitis viruses in California, USA.
Gambel's and California quail were infected repeatedly whenever western equine encephalomyelitis virus (WEEV), St. Louis encephalitis virus (SLEV), and (WNV) West Nile virus were active during summer in California. The timing of virus appearance and quail infection coincided well with the appearance of chicks in nature, leading us to hypothesize that large coveys containing these non-immune birds could be important in focal virus amplification in rural settings. However, experimental infection studies with chicks, juveniles, and adults of both quail species using sympatric strains of WEEV, SLEV, and WNV indicated that only immature birds were competent hosts for WEEV, producing viremias sufficiently elevated to efficiently infect Culex tarsalis mosquitoes. Quail were less competent hosts for WNV and were incompetent for SLEV. Large populations of quail that frequently are infected with SLEV or WNV, but produce low to moderate viremias, may serve as dead end hosts for these viruses. Due to their abundance and repeated infection, these birds may attenuate virus amplification in rural areas of California and possibly could be one reason why WNV epidemics seem to occur more frequently in urban and periurban than in rural landscapes.
Reisen
William K
WK
Center for Vectorborne Diseases, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California 95616, USA. arbo123@pacbell.net
Martinez
Vincent M
VM
Fang
Ying
Y
Garcia
Sandra
S
Ashtari
Siranoosh
S
Wheeler
Sarah S
SS
Carroll
Brian D
BD
D000367:Age Factors; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001715:Bird Diseases / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D002140:California / Q000453:epidemiology; D003465:Culex / Q000821:virology*; D004196:Disease Outbreaks / Q000662:veterinary; D004197:Disease Reservoirs / Q000662:veterinary* / Q000821:virology; D004198:Disease Susceptibility / Q000662:veterinary; D004665:Encephalitis Virus, St. Louis / Q000276:immunology; D004667:Encephalitis Virus, Western Equine / Q000276:immunology; D004674:Encephalitis, St. Louis / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary; D004683:Encephalomyelitis, Equine / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary; D007303:Insect Vectors / Q000821:virology*; D011784:Quail / Q000469:parasitology / Q000821:virology; D016036:Seroepidemiologic Studies; D013045:Species Specificity; D014766:Viremia / Q000662:veterinary; D014901:West Nile Fever / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary; D014902:West Nile virus / Q000276:immunology
D000914:Antibodies, Viral