A PUTATIVE LEISHMANIA-PANAMENSIS LEISHMANIA-BRAZILIENSIS HYBRID IS A CAUSATIVE AGENT OF HUMAN CUTANEOUS LEISHMANIASIS IN NICARAGUA

As part of a survey of human leishmaniasis in Nicaragua we examined ph enotypic and genotypic characteristics of 40 Leishmania isolates. We i dentified 3 distinct parasites associated with cutaneous disease in th is area; Leishmania panamensis (40% of cases), Leishmania braziliensis (33%), and a strain which exhibits the heterozygous isoenzyme and DNA fingerprinting patterns expected of a L. panamensis/L. braziliensis h ybrid (27 %). There was complete correlation between the isoenzyme and DNA data for each of the putative hybrids examined. All of the 'hybri ds' were obtained from foci in the northern region of the country wher e L. panamensis and L. braziliensis occur sympatrically. These observa tions provide strong evidence for sexual reproduction in New World Lei shmania populations and suggest that it is of taxonomic and epidemiolo gical significance.