Visceral leishmaniasis in large Brazilian cities: challenges for control.

The objectives of this article were to discuss the rapid spread of visceral leishmaniasis in urban areas of Brazil and to raise practical questions and perspectives related to control of the disease. Among the proposed methods, the elimination of seropositive dogs is the most controversial and least accepted by society. Its impact on incidence rates varies among studies (positive in some and relatively unimportant in others). Treatment of infected dogs, although widespread in veterinary practice, is based on studies with weak scientific evidence. Insecticide spraying of areas is more acceptable to the population, but is costly and operationally difficult. Intra and inter-urban factors have scarcely been studied and may affect control of the disease. Finally, the article discusses the use of deltamethrin-impregnated dog collars and vaccines, with high expectations for impact on disease transmission, although no product currently available on the market has been fully evaluated, so that further studies are required.