EPIDEMIOLOGY OF BOVINE ANAPLASMOSIS AND BABESIOSIS IN COSTA-RICA

A serum bank created by the National Brucellosis Control Program durin g 1991 consisted of approximately 4000 sera collected from farms in ea ch of the seven provinces in Costa Rica. Sera were used to determine t he prevalence of antibodies directed against Anaplasma marginale, Babe sia bigemina and Babesia bovis in Costa Rica and to study some geograp hical, ecological and management factors which could influence the epi demiology of the infection. The overall seroprevalence in bovines was 72.4%, 55.4% and 54. 1% for A. marginale, B. bigemina and B. bovis, re spectively. The Moran's index or spatial autocorrelation coefficient, which tests the significance of geographical patterns in disease distr ibution, indicated two foci of seropositivity in the country for B. bo vis: one located mainly in the dry tropical forest and the other locat ed in the tropical moist forest. Suggested foci were corroborated by a risk assessment using the random effects models.