Risk model to assess livestock rabies exposure in the state of São Paulo, Brazil

Abstract

To propose a qualitative risk assessment model for the study of livestock exposure to rabies virus from the vampire bat Desmodus rotundus (antigenic variant 3) in the Paraíba do Sul river valley, state of São Paulo, Brazil. Based on scenario trees generated considering rabies exposure and its spread, we estimated the probability of rabies cases in large livestock and its association with the geographic location of livestock farms. Assessment of the historical series of rabies focal points in the first semester of 2006, which was used to validate the risk assessment model, revealed that 81.8% of the focal points were adequately foreseen by the model and could have been prevented with strategic vaccination in high-risk areas. The adoption of control measures specifically targeting high-risk areas might entail a substantial decrease in the number of rabies focal points, at a low cost and with optimal movement of field teams.