Evaluation of point-of-care tests for cutaneous leishmaniasis diagnosis in Kabul, Afghanistan

Abstract

BackgroundKabul (Afghanistan) is a major focus of cutaneous leishmaniasis (CL) caused by Leishmania tropica. Microscopy remains the reference test for diagnosis despite its low performance. We evaluated whether Loopamp™ Leishmania Detection Kit (Loopamp) and CL Detect™ Rapid Test (CL Detect), detecting Leishmania DNA and antigen, respectively could improve CL diagnosis.MethodsA diagnostic accuracy study with prospective inclusion was conducted in a leishmaniasis reference clinic in Kabul. Slit skin samples from CL suspects were analysed by microscopy. Samples taken with a dental broach were tested with CL Detect, Loopamp, and PCR. All samples were transferred to the Academic Medical Center (AMC, the Netherlands) for PCR and Loopamp analyses. The diagnostic performance of the tests was evaluated against a reference combining microscopy and PCR.Findings274 CL suspects were included in the study. In Kabul, CL Detect had a 65·4% sensitivity [95% Confidence Interval (CI): 59.2–71.2%] and a 100% specificity [95% CI: 80.5–100%], while these were 87.6% [95%CI: 82.9–91.3%] and 70.6% [95% CI: 44.0–89.7%] for Loopamp. At AMC the Loopamp's sensitivity (92.2% [95% CI: 88.2–95.2%]) and specificity (94.1% [95% CI: 71.3–99.8%]) were higher. An algorithm where CL Detect negative suspects would be tested by Loopamp yielded a 93.4% sensitivity [95% CI: 89.6–96.1%] and a 94.1% specificity [95% CI: 71.3–99.8%] when Loopamp's performance at AMC was used.InterpretationThe high specificity of CL Detect and the performance of Loopamp allow their use in a diagnostic algorithm that would minimize the number of CL patients referred for confirmation.FundFederal Ministry of Education and Research, Germany.

Accuracy of a Rapid Diagnostic Test Based on Antigen Detection for the Diagnosis of Cutaneous Leishmaniasis in Patients with Suggestive Skin Lesions in Morocco

“…Our results are consistent with those from a study in Afghanistan, in which the same CL RDT was used in 257 patients with mostly nodular lesions, living in Kabul, where L. tropica is known to be the predominant species. 32 The accuracy of the RDT compared with a reference standard based on qPCR and microscopy was: Se = 65% [95% CI: 59–71]; Sp = 100%; PPV = 100% [95% CI: 98–100]; and NPV = 16% [95% CI: 9–24]. 32 …”

“… 32 The accuracy of the RDT compared with a reference standard based on qPCR and microscopy was: Se = 65% [95% CI: 59–71]; Sp = 100%; PPV = 100% [95% CI: 98–100]; and NPV = 16% [95% CI: 9–24]. 32 …”

One Health Approach to Leishmaniases: Understanding the Disease Dynamics through Diagnostic Tools

“…Moreover, due to its complex transmission cycle, involving the various biological entities, identifying the responsible Leishmania species is crucial in disease control and interventions [ 1 ]. Early and accurate detection as well as improving patients’ outcomes [ 110 ] also provides imperative data for eco-epidemiological studies to monitor and assess the outbreak and evaluate current control measures that are in place in endemic regions. A diagnosis of leishmaniases is often made by evaluating the clinical manifestations of the disease in the patient, followed by one or more laboratory diagnostic tests ( Figure 3 ).…”

Cutaneous Leishmaniasis Due to Leishmania aethiopica

“…PCR has been introduced in Ethiopia in the last 10 years, first mainly for species identification [6], [79], but later also for diagnosis [32]. New promising tests such as the loop-mediated isothermal amplification (LAMP) assay and the CL detect Rapid Test [80], [81] have not yet been evaluated in Ethiopia.…”