Contribution de la PCR en temps réel dans le diagnostic biologique de la leishmaniose cutanée : expérience de l’institut Pasteur de Tunis

Abstract

The aim of this study was to assess the performance of real-time PCR (qPCR) in the diagnosis of cutaneous leishmaniasis (CL). Culture, direct microscopic examination (DE) and qPCR were performed on dermal exudate samples collected from 235 confirmed CL cases. The qPCR was found to be more sensitive than other diagnostic techniques and was able to correct the diagnosis in 49 patients (20.9%) with negative dermal smears. Median parasitic load (PL) of the 49 dermal exudates with negative DE was lower than that of positive ones in microscopy. This suggests that PL likely impact the sensitivity of microscopy. On the other hand, qPCR was performed on DNA extracts of scraped products collected from the 23 out of 49 archived negative Giemsa-stained slides and showed 11 positive. Parasitic loads in the latter smears were lower than those in corresponding exudates. The results highlight qPCR relevance for the diagnosis of CL and recommend its use directly on dermal exudates collected from CL lesions.