Vectors of cutaneous leishmaniasis in the State of Campeche
were studied in relation to the transmission cycle of
Leishmania (Le.) mexicana. To determine how
transmission of leishmaniasis occurs, we collected
phlebotomine sand flies for two years. In the first year
(October 1990 to November 1991) the collections were made with
CDC light traps, Shannon traps and direct captures at natural
shelters around the village ({200 m) of La Libertad. In the
second year (February 1993 to January 1994) the catches were
performed at 8 km southeast of La Libertad in the forest.
Female sand flies were examined for Leishmania. During
the first year, 347 sand flies of nine species were collected,
most of which were Lutzomyia deleoni (61.3%). When all
nine species were considered, more females than males were
captured. Low densities of anthropophillic species of sand
flies around the village indicated that sylvatic transmission
was taking place. For the second year, 1484 sand flies of 16
species were caught. The most common were L. olmeca
olmeca (21.7%), L. cruciata (19.2%) and L.
ovallesi (14.1%). Similarly, more females were caught than
males. Thirty-five females of five species were found infected
with flagellates believed to be Leishmania sp. The
highest infection rate was found in L. olmeca olmeca
(7.1%) followed by L. cruciata (4.5%) and L.
ovallesi (1.1%). These data plus other evidence on the
epidemiology of human cases and results from reservoir studies
are discussed in relation to the sylvatic transmission cycle.
