Eco-epidemiology of cutaneous leishmaniasis in Argentina

SALOMÓN OD, QUINTANA MG, ROSA JR, ACARDI, SA

Lima, Peru.

Simposio; ISOPS. 6th International Symposium On Phlebotomine Sandflies; 2008

American Cutaneous Leishmaniasis (ACL) in endemic in Argentina from the northern border to 38° SL. There are 7000 ACL cases reported since the first outbreak in 1985. Leishmania braziliensis was isolated from cases associated with outbreaks, L. guyanensis and L. amazonesis were also reported. Natural infections were found (PCR) in Lutzomyia neivai, Lu. whitmani and Lu. quinquefer. The eco-epidemiology of ACL based on phlebotomine distribution in the 9 endemic provinces (over 150,000 sand flies) has being studied in three scales of time and space:  1) Capture site/day-week: Source forest populations can colonize the peridomestic environment (local extinguible populations). The distribution of peridomestic Lu. neivai varies according to the spatial distribution of food, ecotone and wooded patches. 2) Epidemic foci/month-year: three scenarios were described including the 19 studied outbreaks: 2a) Forest transmission/cases, associated with activities within the woods (Lu. whitmani in NE). 2b) Forest transmission/peridomestic cases, associated with landscape modification as deforestation-human settlement or local overflow (Lu. neivai). 2c) Peridomestic transmission/cases, associated with adaptation of vector species to modified environments (Lu. neivai). 3) Regional/decades: ACL epidemic wave started in the 80’s concurrent with the appearance or prevalence of Lu. neivai. Further, transects from primary forest to villages in the hyper-endemic area had increasing relative and total abundance of Lu. neivai, and increasing ACL incidence. In the central dry region (Chaco) the sparsed or family clustered ACL cases are still associated with Lu. migonei without Lu. neivai. Phlebotomine are better indicators in time and space of ACL transmission than human ACL data from secondary sources. In Argentina the relative and absolute abundance of Lu. neivai and Lu. migonei could be used for surveillance and monitoring the ACL outbreak risk. Recommendations of control were developed for each scale and scenario.