Lutzomyia longiflocosa as suspected vector of cutaneous leishmaniasis in a focus of cutaneous leishmaniasis on the sub-andean region of Tolima department, Colombia, and the knowledge on sandflies by the inhabitants

Abstract

Introduction. Between 2003 and 2004 the largest epidemic of cutaneous leishmaniasis in Colombia (2,810 cases, with the highest incidence of 6,202 x 100,000 in 2004) occurred in the sub-Andean rural area of the municipalities of Chaparral and San Antonio in the department of Tolima.

Objective. The present study was carried out to identify suspected vectors and to establish the knowledge that the inhabitants have about sand flies in order to use this information for vector control.

Materials and methods. 46 houses were sampled with CDC light traps set up indoors to establish the sand fly species composition, abundance and the percentage of infestation. Houses were examined during daylight to identify endophily. A questionnaire was applied in order to estimate the knowledge about sand flies, their role in transmission and the sites and seasons of highest abundance.

Results. Three anthropophilic sand fly species of possible epidemiological importance were found. L. longiflocosa was the dominant sand fly species accounting for 81.7% (192 / 235) of all catches and infested the highest number of houses (41.7%). The other two species were L. columbiana and L. nuneztovari, with relative abundances of 3.4% and 2.1%, respectively, and house infestations of 13.0% and 6.5%, respectively. There was no evidence of endophilic behavior. Inhabitants recognized sand flies and their role in transmission. They identified the houses and the dry season as the site and time period of highest sand fly abundance.

Conclusions. Based on its high anthropophily, predominance and apparent endophagic behavior, L. longiflocosa is the most probable vector of leishmaniasis indoors. L. columbiana and L. nuneztovari could be involved as secondary vectors outdoors. The importance of these findings on sand fly control is discussed.