DNA extraction and amplification of Leishmania from archived, Giemsa-stained slides, for the diagnosis of cutaneous leishmaniasis by PCR

DNA was isolated from 92 Giemsa-stained smears of lesions from suspected cases of cutaneous leishmaniasis and used for PCR-based diagnosis of Leishmania infection. Each smear had been examined under a light microscope at x 1000 and scored for amastigote numbers. Although the smears had been stored for up to 4 years, all the microscopy-positive slides were also positive by PCR and four of the 14 smears that were negative by microscopy (although of lesions that were clinically consistent with leishmaniasis) were also PCR-positive. PCR-based investigations therefore appear to offer an effective method to confirm suspected cases of cutaneous leishmaniasis using (even archived) samples that have been collected, from humans (and reservoir hosts) in the field, by simple methods.