Abstract

GARCEZ, Lourdes Maria et al. Surveillance of visceral leishmaniasis in epidemiologically distinct locations in Juruti, a mining municipality in Pará State, Brazil. Rev Pan-Amaz Saude [online]. 2010, vol.1, n.1, pp.107-116. ISSN 2176-6215.  http://dx.doi.org/10.5123/S2176-62232010000100016.

Surveillance actions for human visceral leishmaniasis (HVL) were carried out in Juruti, a mining municipality in Pará State. A peri-urban (Santa Maria-SM) and a rural (Capiranga-CA) location were selected with or without HVL, respectively, for the execution of four biannual serologic inquiries (lysate ELISA) in canine populations (SM = 94, CA = 45) and three entomological surveys (CDC light traps, 18-6 h x4). Subsequently, the clinical status, as well as the infection by Leishmania, was investigated in 53 dogs (SM = 28; CA = 25) with parasitological (bone marrow/lymph, Giemsa), molecular (peripheral blood leukocytes, kDNA-PCR) and serological (ELISA) diagnoses assessing different antigens (lysate, K39, Hsp83 - screen test, ROC curve). Seroprevalence varied in SM (45; 40; 15; 15%) and in CA (22; 30; 8.5; 0%), presenting increasing average IgG rates in SM (320; 378; 951; 1866; p <0.05) despite the euthanasia of dogs after the second survey, and stable average IgG rates in CA (100; 159; 141; 0), where euthanasia was not conducted. The frequency rates of Lutzomyia longipalpis/Lutzomyia spp. differed in SM (279/296) and CA (4/6). Clinical and laboratory results were similar for dogs from SM and CA, respectively: infection (parasitological examination: 86 and 84%; kDNA-PCR: 100%), clinical status (asymptomatic: 43 and 56%; symptomatic: 57 and 44%), and specificity by ELISA (100%). On the other hand, sensitivity (lysate: 44 and 18%; Hsp83: 48 and 27%; K39: 48 and 41%) and IgG levels (≤ 6,400; ≤ 200) varied, respectively. The profile of canine infection in localities with or without HVL transmission differed only in terms of the level/evolution of IgG, which makes the temporality of investigations necessary, especially in quiet and isolated areas that present a low vector density and where the euthanasia of dogs would become unnecessary. The best serological test was ELISA-K39.

Keywords : Leishmaniasis; Visceral; Dogs; Enzyme-Linked Immunosorbent Assay; Polymerase Chain Reaction; Insect Vectors; Epidemiologic Surveillance.

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