Our results have shown the wide diversity of parasites within New
World Leishmania. Biochemical and molecular
characterization of species within the genus has revealed that
much of the population heterogeneity has a genetic basis. The
source of genetic diversity among Leishmania appears to
arise from predominantly asexual, clonal reproduction, although
occasional bouts of sexual reproduction can not be ruled out.
Genetic variation is extensive with some clones widely
distributed and others seemingly unique and localized to a
particular endemic focus. Epidemiological studies of
leishmaniasis has been directed to the ecology and dynamics of
transmission of Leishmania species/variants, particularly
in localized areas. Future research using molecular techniques
should aim to identify and follow Leishmania types in
nature and correlate genetic typing with important clinical
characteristics such as virulence, pathogenicity, drug resistance
and antigenic variation. The epidemiological significance of such
variation not only has important implications for the control of
the leishmaniases, but would also help to elucidate the
evolutionary biology of the causative agents.
