[Surveillance of St. Louis encephalitis, Eastern equine and Western equine in the province of Ciego de Avila].

Serological studies were carried out using the haemagglutination inhibition and neutralization tests so as to know the circulation dynamics of some arboviruses with the use of Western and Eastern equine encephalitis antigens and St Louis encephalitis antigens in human serum from sound and symptomatic individuals, as well as from sentinel birds, between 1987 and 1991, and during 1994. 1.7% of the asymptomatic subjects tested presented neutralizing antibodies to to Eastern equine and 4.8% to St Louis encephalitis. 16 patients with seroconversion by haemagglutination inhibition to St Louis virus were detected. Surveillance of sentinel birds showed that during 1988, 1989, and 1994. St. Louis circulated in the municipalities of Morón, Bolivia and Chambas; whereas in the latter the Eastern equine encephalitis circulated in 1988 and 1989. Antibodies to Western equine encephalitis were detected in sound individuals by haemagglutination inhibition due seemingly to heterologous antibodies, since there were no neutralizing antibodies against this virus.