Clinical utility of polymerase chain reaction-based detection of Leishmania in the diagnosis of American cutaneous leishmaniasis.

We evaluated the use of polymerase chain reaction (PCR) for diagnosis of American cutaneous leishmaniasis (ACL) in an area in Bahia, Brazil, where Leishmania braziliensis is endemic. Leishmania DNA was detected in 50 cases, yielding a positivity rate of 100%, which was higher than the rates for all of the other diagnostic methods studied--namely, the Montenegro skin test, anti-Leishmania serological testing, and microscopic examination of lesion biopsy specimens. These findings have led us to propose guidelines for the diagnosis of ACL that use PCR as the principal means of parasitological confirmation of cases.