The aetiological agents of American cutaneous leishmaniasis in the municipality of Monte Negro, Rondônia state, western Amazonia, Brazil.

Although American cutaneous leishmaniasis (ACL) is one of the most important endemic diseases in the Brazilian state of Rondônia, there is very little information on the species of parasite involved. The objective of the present study was to identify the Leishmania species causing ACL in the Monte Negro municipality of the state. Over a 6-year period (1997-2002), the skin lesions of 233 patients were examined while the patients were attending an outpatients' clinic at the University of São Paulo's Advanced Research Unit in Monte Negro. ACL was diagnosed in 137 (58.8%) of the patients and leishmanial parasites were successfully isolated from 14 of the ACL cases. Using a panel of 24 monoclonal antibodies, 12 of the 14 isolates were identified, as L. (Viannia) braziliensis (seven), L. (V.) lainsoni (one), a L. (V.) lainsoni-like species (two), a L. (V.) guyanensis-like species (one), or a L. (Viannia) species that was different from all named species (one). These are the first records of human infection with L. (V.) braziliensis and L. (V.) lainsoni in Rondônia.