Comparative Analysis of Microscopic and PCR Methods for Leishmaniasis Diagnosis

Abstract

Background: Leishmaniasis is a vector-borne disease caused by protozoan parasites of the genus Leishmania, transmitted primarily through the bite of infected sandflies. It manifests in various forms, including cutaneous, mucocutaneous, and visceral leishmaniasis, each presenting unique clinical challenges. Accurate diagnosis is critical for effective treatment and management. Traditional diagnostic methods include microscopy, which involves identifying Leishmania amastigotes in stained tissue samples or smears. While microscopy is cost-effective and widely accessible, it has limitations in sensitivity and specificity, particularly in cases with low parasite loads or atypical presentations. In contrast, polymerase chain reaction (PCR) offers a molecular approach that can detect even minute quantities of parasite DNA, potentially improving diagnostic accuracy. Aims: This study aims to compare the diagnostic efficacy of microscopy and PCR in patients suspected of leishmaniasis Study Design: This study involved a comparative analysis of microscopy and PCR methods for diagnosing leishmaniasis using clinical samples from patients presenting with symptoms consistent with the disease we have compared the sensitivity of the conventional methods microscopy against PCR amplification of parasite kinetoplast DNA from these samples. Place and Duration of Study: This was a retrospective observational study conducted between March and December 2024, study performed in NCDC leishmania dermatology clinical in Tripoli, the study included 116 patients who presented with skin lesions in various regions of Libya with cutaneous leishmaniasis referred to the Dermatology and Leishmaniasis clinic who had signs of cutaneous leishmaniasis Methodology: The samples (n=116) were obtained from National Center for Diseases Control - LIBYA the patients clinically suspected of CL Results: The majority of lesions were found on the lower limbs (46%), followed by the upper limbs (28%), and facial lesions (18%).  PCR result showed that 104 (89.66%) were positive for Cutaneous Leishmaniasis. 12 (10.34%) were negative for both PCR and microscopy. Preliminary results indicated that the Microscopy has high sensitivity (100%) but lower specificity (77.4%). PCR's positive predictive value (84%) and negative predictive value (100%) suggest high diagnostic accuracy. Conclusion: The results suggest that PCR is a reliable diagnostic tool for detecting Leishmaniasis. These findings can inform future research and public health strategies aimed at controlling and preventing CL in endemic regions