The laboratory and field observations summarized in this
paper on visceral leishmaniasis ecology in the State of
Bahia,Brazil are based on the author's observations over the
past 35 years in a number of state's foci, public health
records and literature citations. The disease is endemic
withepidemic outbreaks occurring every ten years and its
geographicaldistribution is expanding rapidly in the last
years. Leishmania chagasi is the main ethiologic agent
of the visceral leishmaniasisbut Le. amazonensis s.
lato was the only leishmania isolated by other authors from
some visceral leishmaniasis human cases in the state.
Lutzomyia longipalpis (with one or two spots on
tergites III and IV and two sized different populations) was
epidemiologically incriminated as the main vector. It was
found naturally infected with promastigotes, and it was
infected with four species of leishmanias in the laboratory.
Although the experimental transmission of Le.
amazonensis by the bite of Lu. longipalpis to
hamsters was performed, the author was not successful in
transmitting Le. chagasi in the same way. The dog is
the most important domestic source for infection of the
vector, however it is not a primary reservoir. The opossum
Didelphis albiventris was found naturally infected
with Le. chagasi but its role as reservoir is unknown.
Foxes and rodents were not found infected with leishmanias in
Bahia.
