Diagnostic Accuracy of Polymerase Chain Reaction Against Giemsa Staining on Tissue Biopsy for Cutaneous Leishmaniasis.

OBJECTIVE

To evaluate the diagnostic accuracy of a commercial real-time polymerase chain reaction (PCR) kit targeting 18S rRNA against Giemsa-stained tissue slides in patients clinically suspected of cutaneous leishmaniasis (CL).

STUDY DESIGN

Cross-sectional analytical study. Place and Duration of the Study: Department of Microbiology, Armed Forces Institute of Pathology / National University of Medical Sciences, Rawalpindi, Pakistan, from July to December 2022.

METHODOLOGY

Samples of skin tissue in 98 patients suspected of CL were evaluated. These samples were subjected to Giemsa-staining for microscopy and real-time PCR. Sensitivity, specificity, and accuracy of the PCR were calculated keeping Giemsa-stained tissue slide microscopy as gold standard.

RESULTS

Out of the 98 tissue samples, 37 were found positive for leishmaniasis on PCR while 13 were found Leishmania positive on microscopy of Giemsa-stained slides. The sensitivity, specificity, and accuracy of the PCR for the detection of Leishmania species were 100%, 71.8%, and 91.8%, respectively with 100% negative predictive value.

CONCLUSION

This study demonstrates that the commercial PCR is a reliable diagnostic test for the diagnosis of CL. The ease, rapidity, and reliability of the PCR make it a dependable tool in diagnostic repertoire of CL.

KEY WORDS

Giemsa stain, Leishmania spp., Polymerase chain reaction, Viasure.