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.

[Evaluation of the development of immunologic response in patients with cutaneous leishmaniasis]. / Evaluación del desarrollo de la respuesta inmunológica en pacientes con Leishmaniasis cutánea.

In this study we present epidemiological and immunological data about cutaneous Leishmaniasis in Panama, in an area where recurrence occurs in 65% of the cases evaluated. The development of the cellular immune response, during clinical evolution of primary and recurrent cases, indicates that initial stimulation index (SI) less than 3 are observed in recurrent cases, while this level is higher than 3 in primary cases. The humoral immune response is related only with the time of clinical evolution. We point out the importance of looking at the population of T lymphocytes quantitatively, as well as looking at the levels of lymphokines, in order to explain the differences that we observed in the cellular immune response.