Molecular epidemiology of Babesia vogeli in dogs from the southeastern region of Rio de Janeiro, Brazil.

Hemoparasitic diseases are prominent in domestic animals, particularly in Brazil, a tropical country with a wide range of vectors. This study investigated the epidemiology of Babesia vogeli in the whole blood of dogs from the southeastern region of Rio de Janeiro, Brazil. Whole blood samples from 390 dogs were screened for the presence of B. vogeli DNA by qPCR using the heat shock protein 70 kDa (hsp70) gene of B. vogeli. Characteristics related to the host and its environment were collected using a questionnaire. Bivariate analysis was used to evaluate each factor individually. A phi correlation test was used to verify collinearity. The variables with p < .1 and a low or moderate correlation with the other variables were selected for the multivariate analysis. Multiple models were created, and the best logistic regression model was chosen using the Akaike Information Criterion (AIC). The final model was used to determine which variables were closely related to B. vogeli infections in dogs. Of the 390 dog blood samples, 15.66% were positive for B. vogeli. The variables cat contact, age, shelter, street or woods access, tick infestation and fur lengthwere included in the final model. Per the logistic regression analysis, three variables explained B. vogeli detection in dogs: age (odds ratio [OR] = 2.12; p-value <.05; confidence interval [CI]: 1.13-3.96), tick infestation (OR = 2.08; p-value <.05; CI: 1.10-3.93) and shelter (OR = 2.22; p-value <.05; CI: 1.16-4.26). These variables were determined to be associated with B. vogeli detection in domiciled dogs in the southeastern region of Rio de Janeiro, Brazil. These data indicate that the age of the animal, the presence of ticks and the lack of shelter directly affect the epidemiology of B. vogeli.