Systematic Review into Diagnostics for Post-Kala-Azar Dermal Leishmaniasis (PKDL)

Area of Science:

• Medical Parasitology
• Infectious Diseases
• Diagnostic Accuracy Research

Background:

• Post-kala-azar dermal leishmaniasis (PKDL) diagnosis is critical due to lengthy, toxic treatments and its role as a reservoir for visceral leishmaniasis (VL).
• Existing diagnostic methods for PKDL require rigorous evaluation to ensure reliable identification and management.

Purpose of the Study:

• To systematically review and summarize the published literature on the diagnostic accuracy of various tests for PKDL.
• To identify gaps in current research and recommend future directions for PKDL diagnostic test evaluation.

Main Methods:

• A comprehensive literature search was conducted in Medline for studies assessing the diagnostic accuracy of any test for PKDL.
• Study quality was evaluated using the QUADAS-2 tool.
• Data from 21 articles, encompassing 43 distinct studies, were extracted, covering serological, molecular, microscopy, and culture-based tests.

Main Results:

• A limited number of studies provided valid diagnostic accuracy estimates, with many employing case-control designs or suboptimal reference standards.
• Significant heterogeneity was observed across studies, particularly in the reference standards used, precluding meta-analysis.
• Twenty-seven studies assessed serological tests (rK39 dipstick, ELISA, DAT, leishmanin), six evaluated molecular tests, eight used microscopy, and two employed cultures.

Conclusions:

• There is a critical need for well-designed diagnostic accuracy trials for PKDL.
• Future research should concurrently evaluate all available diagnostic modalities, including clinical signs, serological, antigen, molecular, and parasitological tests.
• Statistical modeling may be valuable for evaluating diagnostics in the absence of a definitive gold standard.