House sparrows, Passer domesticus (L.), as hosts of arboviruses in Hale County, Texas. II. Laboratory studies with Western equine encephalitis virus.

Abstract

Western equine encephalitis (WEE) virus was artificially inoculated into nestling progeny of two flocks of house sparrows, Passer domesticus, one flock of which contained WEE-hemagglutination inhibition (HI) positive breeders and the other WEE-HI negative breeders. Ten-day-old chickens from WEE-immune and nonimmune flocks were similarly tested. Nestlings 4 to 16 days old from the immune flock were seemingly as susceptible to infection with WEE virus as were birds of the same age from the nonimmune flock. However, as shown earlier by other workers, chickens hatched from WEE-immune parents were uniformly refractory to infection with WEE virus. The results obtained in this study serve as a basis for explaining how the high annual incidence of WEE virus infection can occur among nestling house sparrows that are progeny of birds from a population in which the average WEE antibody prevalence ranged from 36% to 56%.