Diagnosis of cutaneous leishmaniasis in Colombia: The sampling site withinlesions influences the sensitivity of parasitologic diagnosis

Parasitologic confirmation of cutaneous leishmaniasis is obligatory before chemotherapy can be considered. Direct microscopic examination of scrapings taken from indurated borders of ulcers has been routinely used as primary method of diagnosis. In this report we compared the sensitivity of examinat ion of dermal scrapings taken from the bottoms of ulcers (BDS) with that of dermal scrapings taken from indurated active margins of lesions (MDS) in a total of 115 patients, The sensitivities of the microscopic examination we re 90.4 and 78.3% for BDS and MDS samples, respectively. When the PCR metho d nas used with a group of 40 patients, we also observed a higher sensitivi ty when BDS samples were examined (80.8% in BDS samples versus 57.7% in MDS samples). The improvement of the diagnostic sensitivity in the BDS samples appears to be related to the higher parasite load and more easily detectab le morphology of amastigotes in the centers of the ulcers, Other parasitolo gic diagnostic methods, such as culture and histopathologic examination of biopsies, are less sensitive (67.5 and 61.3%, respectively), Aspirate cultu re, however, was shown to be the most sensitive method for the diagnosis of patients with chronic ulcers, When microscopic examinations of both MDS an d BDS samples are combined, the sensitivity of diagnosis may rise up to 94% . We therefore recommend this method as a primary routine procedure for dia gnosis of cutaneous leishmaniasis.