Polymerase Chain Reaction [PCR] versus Slit Skin Smear in Diagnosis of Leprosy

Leprosy is a chronic infectious disease where delay in diagnosis or treatment can lead to deformities, disabilities and social stigma for the rest of patient’s life. Definite diagnosis of leprosy has long been performed based on clinical picture, histopathology and/or the presence of acid-fast bacilli (AFB) from tissue smears or tissue sections stained by ziehlneelsen. Aim of the work: In this study, we evaluated the usefulness of PCR analysis for detection of M.leprae in the serum ,as less invasive technique, in comparison to skin slit smear for the diagnosis of leprosy. Patients and methods: 30 untreated leprosy patients were included in this study (9 multipacillary, 21 paucipacillary) where skin slit smears were taken from all patients, So as serum samples for PCR test. Results :Negative skin smears for AFB had been obtained in 20 patients with a rate of positivity of 33%.Serum PCR was positive in 20 patients with an overall rate of positivity of 67% confirming the diagnosis in 11 out of 20 cases with SSS negative. Conclusion: positive conventional serum PCR results were obtained in 20 out of 30 leprosy cases (66.6%), When compared to SSS results (33.3%) indicating its future standardization and use for diagnostic purposes especially in early leprosy cases.