Abstract
In rural areas in Morocco, diagnosing cutaneous leishmaniasis (CL) can be challenging. We evaluated the accuracy of a rapid diagnostic test (RDT) based on antigen detection, CL Detect Rapid Test(™) (Inbios International Inc., Seattle, WA), in this setting. We consecutively recruited patients with new skin ulcers in nine primary health centers. We took a dental broach sample for the RDT and two other tissue samples by scraping the border and center of the lesion with a scalpel and smearing it on a slide. We duplicated each smear by pressing a clean slide against it and processed the slides by microscopy, polymerase chain reaction (PCR) internal transcribed spacer 1, and kDNA minicircle PCR. In a subgroup with positive PCR, the Leishmania species was identified using PCR-restriction fragment length polymorphism and PCR-sequencing of hsp70 genes. A participant with positive microscopy and/or PCR was considered a confirmed CL case. We computed sensitivity (Se) and specificity (Sp) of the RDT compared with this reference standard (ClinicalTrials.gov registration: NCT02979002). Between December 2016 and July 2017, we included 219 patients, 50% of them were under 18 years old. Rapid diagnostic test Se was 68% [95% confidence interval (CI): 61-74], Sp 94% [95% CI: 91-97], positive predictive value 95% [95% CI: 92-98], and negative predictive value 64% [95% CI: 58-70]. Despite its low Se, this novel RDT is a useful addition to clinical management of CL in Morocco, especially in isolated localities. Rapid diagnostic test-positive lesions can be treated as CL; but when RDT negative, microscopy should be done in a second step. The Se of the RDT can probably be optimized by improving the sampling procedure.