Molecular techniques in the characterization of Leishmania isolates from Central America

The public-health problems caused by leishmaniasis in most countries in Central America are becoming more severe. This is partly because of the increasing size of the human populations that are at risk and their migratory patterns. Annual incidence of the disease in Costa Rica, Honduras, Guatemala, Panama and Nicaragua is estimated to be as high as 20,000 cases. Regional changes in the epidemiology of the various Leishmania spp. present have emphasized the need for innovative, sensitive and accurate diagnostic tools. PCR and isoenzyme, monoclonal antibody, schizodeme, DNA-probe and random-amplified, polymorphic DNA analyses have been tested. Preliminary indications that Leishmania chagasi was present in Costa Rica and Honduras and that interspecific hybrids occurred in Nicaragua have been confirmed using these methods. The distribution of the mexicana complex was also found to be broader and more heterogeneous than initially expected. Overall, there was 87% concordance between the results produced using the different techniques.