Autochthonous Canine and Human Visceral leishmaniases caused by Leishmania (Leishmania) Infantum in Northwestern Argentina

MARCO JD; BARROSO PA; LOCATELLI FM; CARDOZO RM; HOYOS CL; MORA MC; GARCIA BUSTOS MF; UNCOS AD; RAMOS F; GENTILE AG; BARRIO AB; KORENAGA M; HASHIGUCHI Y; BASOMBRÍO MA

Porto de Galinhas

Congreso; Fifth World Congress on Leishmaniasis; 2013

Leishmaniasis is a zoonotic disease, and its visceral form (VL) has been given an attention as an emerging infectious disease in Argentina. Recently we reported an autochthonous human case from Salta province in the northwestern Argentina, incriminating Leishmania (Leishmania) infantum as its causative agent. Since the dog is considered a primary reservoir host of this parasite, we conducted a survey in the?putative? transmission area referred by the patient reported. Spleen aspirates and peripheral blood, together with clinical data were taken from 77 dogs, recruited from northern rural areas of the province. Diagnosis of canine leishmaniasis (CanL) was done based on the combination of the following methods: 1) cultures, 2) smears, 3) kDNA-PCR, 4) Nested PCR and cytochrome b gene sequencing (cyt b sequencing) of spleen samples, and 5) rK-39 strip test of sera from the dogs examined. The sensitivity - specificity of these methods were 1) 30 - 100, 2) 20 - 100, 3) 100 - 81.3, 4) 70 - 100, and 5) 90 - 86.6%, respectively. The CanL prevalence was 12.9% in the studied area. By cyt b sequencing, two genotypes of L. (L.) infantum, LiA1 and LiA2, were found in five and two out of 10 CanL cases, respectively. LiA2 was also identified for the first time in two human VL cases in the area. In the present study, thus, based on a validated molecular method, L. (L.) infantum was incriminated as the causative agent of both human VL and CanL in the ?Chaco Occidental? region, the xerophytic lowland plain of northern Argentina. In near future, it will be necessary to enhance the diagnostic performance of local CanL, developing/improving the available techniques. Also, the identification of so far unknown wild reservoirs acting as the main source of the parasite, and the description of their enzootic cycle in this area will be needed.