Dados do Trabalho

Título

Parasitological test (Knott Test) for Dirofilaria immitis in dogs and cats rescued from the Zoonosis Surveillance Unit in coastal regions of São Paulo State

Introdução

Heartworm disease is a zoonosis that infects several vertebrates and is caused by nematodes belonging to the genus Dirofilaria, with the species Dirofilaria immitis (D. immitis) being the best-known species. The disease is transmitted by the bite of mosquitoes of the genera Aedes, Culex and Anopheles. In Brazil, the disease is sometimes underdiagnosed and asymptomatic when in milder stages, being endemic in coastal regions, due to high temperatures. Dogs and cats present in Zoonosis Surveillance Units (ZSUs) usually come from the streets, places where they have been exposed to various agents. The close contact of these animals with humans and the existence of mosquito vectors in the environment can increase the risk of transmission of zoonoses. The diagnosis and monitoring of these animals are essential for controlling the heartworm disease, allowing the development of control and prevention programs, reducing the spread of the disease and protecting humans, animals and the environment.

Objetivo (s)

To investigate the occurrence of D. immitis in 82 blood samples from dogs and cats from the ZSUs of six municipalities on the coast of the state of São Paulo, Brazil.

Material e Métodos

The samples came from the ZSUs of Peruíbe, Itanhaém, Mongaguá, Guarujá, São Sebastião and Ubatuba, totaling 82 animals. Blood collection was carried out by the responsible veterinarian of the institution, and was carried out by peripheral venipuncture. The parasitological test was performed using the Modified Knott technique, in which originally blood samples (1 mL) are distributed into a 15 mL conical tube containing 9 mL of 2% formaldehyde solution. Then, the tube is homogenized and centrifuge for 10 minutes at 650 xg. The supernatant is removed and 100 uL of methylene blue (0.1%) is added to the pellet. An aliquot of 20 uL of the sediment is added to a slide with a coverslip for reading under optical microscopy using a 10X objective.

Resultados e Conclusão

Five blood samples (6.1%) were suggestive of D. immitis; the samples were from one canine and one feline from Ubatuba, one canine from Mongaguá, one canine from São Sebastião and one feline from Peruíbe. In all ZSUs the animals were adults, with four of the five suggestive males being males. The results demonstrate the relevance of investigating heartworm disease in dogs and cats, as these animals can be reservoirs of the parasite. The diagnosis of zoonosis is relevant, because in the context of One Health, this discovery allows the implementation of preventive measures.

Palavras Chave

Zoonosis; Heartworm Disease; Knott Test; Canine; Feline; One health