PCR performance for the diagnosis of cutaneous leishmaniasis caused by Leishmania viannia complex using biopsy samples, compared with exudate samples from skin lesions on filter paper

Abstract

Background Cutaneous leishmaniasis (CL) is generally diagnosed by molecular methods, including PCR, using biopsy samples, skin scrapings and clinical exudates. In this study, we assessed the PCR performance for diagnosis of CL using skin of biopsy samples vs PCR of skin lesion exudate samples on filter paper and compared the diagnostic concordance of PCR using both sampling methods. Methods We assessed the PCR performance using 80 skin biopsy samples and 80 filter paper samples containing exudates from skin lesions obtained from 74 patients with clinical suspicion of CL in Cusco, Peru. Results : PCR using skin biopsy samples had superior diagnostic accuracy compared with filter paper PCR (62.5% [50/80] vs 38.7% [31/80], respectively; p˂0.005) and the diagnostic concordance between both sampling methods was ‘moderate’ (kappa coefficient=0.50, 95% CI 0.98 to 1.0). Conclusions PCR using biopsy samples remains the standard for diagnosis of CL.

Characterization of Leishmania spp. Causing Cutaneous Lesions with a Negative Parasitological Diagnosis in Panama

“…In general, molecular methods are an excellent alternative for the early detection of patients infected with Leishmania parasites, which helps to rapidly establish timely treatment, as well as characterize the parasite species involved [ 33 ]. Based on this observation, numerous studies argue that molecular methods represent a reliable, specific, and sensitive alternative that should be part of the routine diagnostic algorithm for CL in the endemic regions of Latin America [ 4 , 12 , 32 ]. In this study, Leishmania parasites present in the lesions of Panamanian patients with negative parasitological results (smear/culture) were characterized.…”

“…Microscopic visualizations of Leishmania amastigotes in stained smears depend on various factors, including Leishmania species, parasitic load, evolution time of the lesion, added bacterial contamination, and the technical execution of the analysis [ 9 , 10 , 11 ]. The implementation of molecular techniques has significantly improved the relatively low sensitivity exhibited by microscopic methods, particularly when used for the diagnosis of CL lesions with a low parasite load [ 10 , 12 , 13 , 14 , 15 ].…”