Ecologic studies of Venezuelan encephalitis virus in southeastern México. V. Infection of domestic animals other than equines.

Abstract

In southeastern México, sera from cattle and pigs, but not the sera of chickens, were frequently positive with Venezuelan encephalitis (VE) virus in hemagglutination-inhibition and neutralization tests. This evidence of natural infection of cattle and swine suggested that they may be involved in cycling virus between vector mosquitoes and vertebrates that amplify it. The geographical distribution of positive cattle and pig sera on the Gulf coast conformed with that of VE virus from other studies, and the low prevalence of antibodies in the arid, irrigated region on the Pacific side of the Isthmus of Tehuantepec corresponded with the inability of other studies to detect much virus activity there. Positive antibody tests of swine sera from the Pacific coast in Chiapas suggested that VE virus was also active there.