Detection of Leishmania (Leishmania) infantum RNA in fleas and ticks collected from naturally infected dogs

Autor(es)

Colombo, Fabio A. ^[1] ; Odorizzi, Rosa M. F. N. ^{[2, 3]} ; Laurenti, Marcia D. ^[4] ; Galati, Eunice A. B. ^[2] ; Canavez, Flavio ^[5] ; Pereira-Chioccola, Vera L. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Adolfo Lutz Registro, Parasitol Lab, BR-01246902 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Saude Publ, Sao Paulo - Brazil

^[3] Secretaria Agr & Abastecimento Estado Sao Paulo, Sao Paulo - Brazil

^[4] Univ Sao Paulo, Fac Med, Sao Paulo - Brazil

^[5] Genoa Biotecnol SA, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Parasitology Research; v. 109, n. 2, p. 267-274, AUG 2011.
• Citações Web of Science: 35

Resumo

The occurrence of the insect vector (sand flies) with low rates of Leishmania infection, as well as autochthonous transmission in the absence of the natural vector in dogs, have been reported. These unexpected data suggest a hypothesis of other arthropods as a possible way of Leishmania transmission. The prevalence of Leishmania (Leishmania) infantum in fleas and ticks collected from dogs with canine visceral leishmaniasis (CVL), as well as parasite viability, were evaluated herein. The presence of L. (L.) infantum was assayed by PCR and ELISA in ectoparasites and biological samples from 73 dogs living in a Brazilian endemic area. As the occurrence of Leishmania DNA in ticks and fleas is expected given their blood-feeding habits, we next investigated whether parasites can remain viable inside ticks. PCR and ELISA confirmed that 83% of the dogs had CVL. Fleas and ticks (nymphs, male and female adults) were collected in 55% and 63% of the 73 dogs, respectively. Out of the 60 dogs with CVL, 80% harbored ectoparasites infected with L. (L.) infantum. The infection rates of the ectoparasites were 23% and 50% for fleas and ticks, respectively. The RNA analysis of the extract from ticks left in laboratory conditions during 7 to 10 days after removal from CVL dogs showed that parasites were alive. In addition, live parasites were also detected inside adult ticks recently molted in laboratory conditions. These findings indicate a higher infection rate of L. (L.) infantum in ticks and fleas, but they do not conclusively demonstrate whether these ticks can act as vectors of CVL, despite the fact that their rates were higher than those previously described in Lutzomyia longipalpis. The presence of viable L. (L.) infantum in ticks suggests the possible importance of dog ectoparasites in CVL dissemination. (AU)

• Processo FAPESP: 08/57245-7 - Leishmaniose visceral americana no estado de São Paulo: estudo de transmissores alternativos
• Beneficiário: Fabio Antonio Colombo
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 08/00520-6 - Leishmaniose visceral americana no Estado de São Paulo: estudo de transmissores alternativos e da diversidade gênica entre os isolados
• Beneficiário: Vera Lúcia Pereira Chioccola
• Modalidade de apoio: Auxílio à Pesquisa - Regular