Evaluation of the CL Detect Rapid Test in Ethiopian patients suspected for Cutaneous Leishmaniasis

PLoS Negl Trop Dis. 2022 Jan 18;16(1):e0010143. doi: 10.1371/journal.pntd.0010143. eCollection 2022 Jan.

Abstract

Background: Cutaneous leishmaniasis (CL) is common in Ethiopia, mainly affecting impoverished populations in rural areas with poor access to health care. CL is routinely diagnosed using skin slit smear microscopy, which requires skilled staff and appropriately equipped laboratories. We evaluated the CL Detect Rapid Test (InBios, Washington, USA), which is supplied with a dental broach sampling device, as a diagnostic alternative which could be used in field settings.

Methodology/principal findings: We evaluated the diagnostic accuracy of the CL Detect Rapid Test on skin slit and dental broach samples from suspected CL patients at the Leishmaniasis Research and Treatment Center in Gondar, Ethiopia. A combined reference test of microscopy and PCR on the skin slit sample was used, which was considered positive if one of the two tests was positive. We recruited 165 patients consecutively, of which 128 (77.6%) were confirmed as CL. All microscopy-positive results (n = 71) were also PCR-positive, and 57 patients were only positive for PCR. Sensitivity of the CL Detect Rapid Test on the skin slit was 31.3% (95% confidence interval (CI) 23.9-39.7), which was significantly higher (p = 0.010) than for the dental broach (22.7%, 95% CI 16.3-30.6). Sensitivity for both methods was significantly lower than for the routinely used microscopy, which had a sensitivity of 55.5% (IQR 46.8-63.8) compared to PCR as a reference.

Conclusions/significance: The diagnostic accuracy of the CL Detect Rapid Test was low for skin slit and dental broach samples. Therefore, we do not recommend its use neither in hospital nor field settings.

Trial registration: This study is registered at ClinicalTrials.gov as NCT03837431.

MeSH terms

  • Adolescent
  • Adult
  • Antigens, Protozoan / analysis*
  • Cross-Sectional Studies
  • DNA, Protozoan / genetics
  • Ethiopia
  • Female
  • Humans
  • Immunoassay / methods*
  • Leishmania / classification
  • Leishmania / genetics
  • Leishmania / immunology*
  • Leishmaniasis, Cutaneous / diagnosis*
  • Male
  • Peroxiredoxins / immunology
  • Polymerase Chain Reaction
  • Sensitivity and Specificity
  • Skin / parasitology*
  • Skin / pathology
  • Young Adult

Substances

  • Antigens, Protozoan
  • DNA, Protozoan
  • Peroxiredoxins

Associated data

  • ClinicalTrials.gov/NCT03837431

Grants and funding

This work was supported by the Directorate-General Development cooperation and Humanitarian Aid (DGD), under the FA4 framework collaboration of the Institute of Tropical Medicine (Antwerp, Belgium) and the University of Gondar (Gondar, Ethiopia), granted to JvG and RM (Rezika Mohammed). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.