Leishmaniasis in Brazil: XX. Prevalence of "enzootic rodent leishmaniasis" (Leishmania mexicana amazonensis), and apparent absence of "pian bois" (Le. braziliensis guyanensis), in plantations of introduced tree species and in other non-climax forests in eastern Amazônia.

In Amazonian Brazil most human leishmaniasis is due to Leishmania braziliensis s.l. and is acquired during the clearing of primary climax forest. One of the largest deforestation projects has taken place on the JARI property where plantations of exotic tree species are grown for paper pulp. The ability of the regional leishmaniasis enzootics to invade plantations was investigated. CDC light-trap catches indicated the phletobomine vectors of Le. b. guyanensis (causing "pian bois" in man) to be very scarce in JARI plantations compared to native-forest controls. It is concluded (drawing on other observations) that the vectors of "pian bois" are unlikely to thrive in any secondary forest. In contrast, catches from mammal traps and rodent-baited (Disney) traps demonstrated the presence in JARI plantations of infected Proechimys guyannensis and large populations of Lutzomyia flaviscutellata, respectively the major rodent reservoir and sandfly vector of Le. mexicana amazonensis. Alone amongst the local vectors of human cutaneous leishmaniasis, Lu. flaviscutellata is adapted to non-climax forests (primary or secondary, natural or man-made; synopsis given). It is predicted that the public health importance of Le. m. amazonensis is unlikely to diminish following the development of Amazônia. This is worrying because ca. 30% of Le. m. amazonensis infections in man cause highly-disfiguring, incurable "diffuse cutaneous leishmaniasis".