WESTERN EQUINE ENCEPHALITIS IN SASKATCHEWAN BIRDS AND MAMMALS 1962–1963

Abstract

In Saskatchewan during 1962 and 1963 Western equine encephalitis (WEE) virus was isolated from 23 English sparrows, one Swainson"s hawk, one mourning dove, one Richardson"s ground squirrel, and one chicken from a sentinel or indicator flock. Our findings indicate that these species provide a source of virus for mosquito infection and transmission during the summer months. Antibody studies revealed a wide range of birds and mammals susceptible to the virus. It would appear that WEE isolates obtained from a mature mourning dove and from an adult Richardson"s ground squirrel, May 19, 1962, were the result of latent infection because of the lack of mosquito activity before this date. Infection rates in domestic birds suggest an agreement with the incidence of clinical cases in man and horses during 1962 and 1963.