The re-emergence of American visceral leishmaniasis in an old focus in Venezuela: Present situation of human and canine infections

The report of a new autochthonous case of human American Visceral Leishmani asis (AVL) in 1992 in the village of Guayabita, Aragua State. Venezuela (10 degrees 16'N, 67 degrees 28'W; 500 m asl), led us to undertake on epidemio logical study in this locality. A demographic survey was conducted using a structured questionnaire in which data was collected regarding sex, age, oc cupation, length of residence in the area and migratory history. A leishman in skin test (LST) was applied and samples of venous blood for counter immu noelectrophoresis (CIEP) and immunofluorescent antibodies (IFAT) tests were drawn. The prevalence of positive LST was 11.4 %. The positivity was highe st among males and increased with age. Young males seemed to be more expose d to infection than females. Since occupation per se did not seem to accoun t for this association, it may be explained as a gender-associated behavior , leading to different degrees of exposure to sand flies. The canine popula tion was also screened for leishmanial infection. One dog was shown to be p arasitologically infected with leishmania sp. Four out of 71 dogs (5.6 %) w ere positive for FG, CIEP, IFAT and Western Blot and 11 (15.5 %) were posit ive for CIEP. These results suggest that after almost 30 years of epidemiol ogical silence, American visceral leishmaniasis has reemerged in this focus .