Objective: To compare the diagnostic efficacy of Multiplex polymerase chain reaction (PCR), Mycobacterium leprae-specific repetitive element (RLEP) PCR and loop-mediated isothermal amplification (LAMP) PCR in the diagnosis of pediatric leprosy as an alternative to slit-skin smear (SSS) examination.
Methods: A cross-sectional study was performed on 26 children aged 0-18 years with characteristic skin lesions of leprosy. SSS examination for acid fast bacilli (AFB) was performed for all children. Additionally, urine, stool and blood samples were tested by three PCR techniques - Multiplex, RLEP and LAMP. The results of these tests were compared with each other and with results of SSS examination for acid fast bacilli (AFB) using appropriate statistical tests.
Results: Out of 26 patients studied, SSS examination was positive for AFB in 7 cases (26.9%). In blood samples, the positivity of Multiplex PCR, RLEP PCR and LAMP PCR was 84.6%, 80.8%, and 80.8%, respectively. Multiplex PCR in blood samples was positive in 100% (n = 7) of SSS positive cases and 84.2% (16 out of 19) of the SSS negative cases (P < 0.001). The positivity of all PCR methods in urine and stool samples was significantly lesser than in blood.
Conclusion: Multiplex PCR in blood sample is a superior diagnostic tool for pediatric leprosy compared to RLEP PCR and LAMP PCR, as well as SSS examination.