Type of lesions.

<p>Type of lesions.</p

Comparison of different types of lesions with three diagnostic tests.

<p>Comparison of different types of lesions with three diagnostic tests.</p

Analysis of three diagnostic assays for cutaneous leishmaniasis using PCR as the gold standard.

<p>Analysis of three diagnostic assays for cutaneous leishmaniasis using PCR as the gold standard.</p

Comparison of parasite detection rates of slit skin smear and IC-RDT with different variables.

<p>Comparison of parasite detection rates of slit skin smear and IC-RDT with different variables.</p

Efficacy of a new rapid diagnostic test kit to diagnose Sri Lankan cutaneous leishmaniasis caused by <i>Leishmania donovani</i>

<div><p>Background</p><p>Cutaneous leishmaniasis (CL) in Sri Lanka is caused by <i>Leishmania donovani</i>. This study assessed the diagnostic value of a new rapid diagnostic immunochromatographic strip (CL-Detect^™ IC-RDT), that captures the peroxidoxin antigen of <i>Leishmania</i> amastigotes.</p><p>Methodology/Principal findings</p><p>We sampled 74 clinically suspected CL lesions, of which 59 (79.7%) were positive by PCR, 43 (58.1%) by Giemsa stained slit skin smear (SSS) and 21 (28.4%) by the new IC-RDT. All samples which were positive either by SSS or IC-RDT or both were positive by PCR. The sensitivities of the IC-RDT and SSS compared to PCR were 36% and 73%, respectively. Fifteen patients from this endemic region were negative by all three tests. Twenty two clinically non-CL skin lesions from a CL non-endemic region were also negative by all three methods. Specificity and PPV of both IC-RDT and SSS compared to PCR were 100%; the NPVs of IC-RDT and SSS were 37% and 58%, respectively. The median parasite grading of the 59 PCR positive samples was 2+ (1–10 parasites/100 HPFs) and IC-RDT positive lesions was 3+ (1–10 parasites /10HPFs). The duration of the lesion was not associated with IC-RDT positivity.</p><p>Conclusions/Significance</p><p>The median parasite grade of Sri Lankan CL lesions is low. The low sensitivities of SSS and CL Detect^™ IC-RDT may be due to low parasite counts or low expression of peroxidoxin antigen in amastigotes of the Sri Lankan <i>L</i>. <i>donovani</i> strain. Our results indicate that negative SSS has to be combined with PCR for confirmation of CL in Sri Lanka. The current commercially available IC-RDT is not suitable to diagnose CL in Sri Lanka; an IC-RDT with improved sensitivity to detect <i>L</i>. <i>donovani</i> would be a valuable addition in the diagnostic tool kit for Sri Lanka.</p></div