Infectivity of seropositive dogs, showing different clinical forms of leishmaniasis, to Lutzomyia longipalpis phlebotomine sand flies.
Visceral leishmaniasis (VL) is a growing zoonosis with an increasing number of new cases and a rapid geographical spreading of the disease. In the present study, a canine survey was carried out in the city of Montes Claros (320,000 inhabitants), an endemic area of American visceral leishmaniasis in the state of Minas Gerais, Brazil. A total number of 4795 dogs were examined by serology, which showed a rate of seropositivity of 5%. Isoenzymatic analysis confirmed Leishmania infantum chagasi as the local aetiological agent of CVL. Canine tissues were assayed for the presence of Leishmania parasite DNA using different techniques. The infectivity of asymptomatic, oligosymptomatic and symptomatic seropositive dogs was tested by xenodiagnosis using laboratory reared Lutzomyia longipalpis. Rates of infection of 5.4%, 5.1% and 28.4% were found for the phlebotomine sand flies that fed in asymptomatic, oligosymptomatic and symptomatic dogs, respectively. Our results indicate that, under experimental conditions, symptomatic dogs are about four times more infective to VL vectors than oligosymptomatic or asymptomatic animals. The lower infectivity rates of dogs displaying any of the last two clinical forms of leishmaniasis, however, must be taken into account in the epidemiology of CVL.
Michalsky
Erika Monteiro
EM
Centro de Pesquisas René Rachou/FIOCRUZ, Av. Augusto de Lima, 1715, Barro Preto, Belo Horizonte, CEP 30190-002, MG, Brazil.
Rocha
Marília Fonseca
MF
da Rocha Lima
Ana Cristina Vianna Mariano
AC
França-Silva
João Carlos
JC
Pires
Marize Quinhone
MQ
Oliveira
Fernanda Santos
FS
Pacheco
Raquel Silva
RS
dos Santos
Sara Lopes
SL
Barata
Ricardo Andrade
RA
Romanha
Alvaro José
AJ
Fortes-Dias
Consuelo Latorre
CL
Dias
Edelberto Santos
ES
D000818:Animals; D001938:Brazil; D004283:Dog Diseases / Q000469:parasitology* / Q000635:transmission; D004285:Dogs; D007527:Isoenzymes / Q000378:metabolism; D018314:Leishmania infantum / Q000201:enzymology / Q000502:physiology*; D007898:Leishmaniasis, Visceral / Q000635:transmission / Q000662:veterinary*; D011159:Population Surveillance; D011576:Psychodidae / Q000469:parasitology* / Q000502:physiology; D013154:Spleen / Q000469:parasitology
D007527:Isoenzymes