Leprosy epidemiological trends and diagnosis delay in three districts of Tanzania: A baseline study

Objectives Leprosy, also known as Hansen's disease, is a slowly progressive and chronic infectious neglected tropical disease (NTD) caused by Mycobacterium leprae. This study was performed to assess the epidemiological trend of leprosy in the past five years in the three study districts in Tanzania in which a leprosy prevention intervention study (PEP4LEP) is implemented, and to determine the case detection delay at baseline. Methods Secondary data from the leprosy registry of the National Tuberculosis and Leprosy Program of Tanzania from 2015 to 2019 were used to describe the epidemiological trends of leprosy for the three study districts: Morogoro, Mvomero, and Lindi district council. A cross-sectional study was also conducted to assess the delay in leprosy diagnosis at baseline. The chi-square test was used to calculate statistical significance. Results Between 2015 and 2019, 657 new leprosy cases were detected in three districts. Of those cases, 247 (37.6%) were female patients, 5 (0.8%) had a grade 2 disability (G2D) and 516 (78.5%) had multibacillary (MB) leprosy. From the 50 adult leprosy patients interviewed for detection delay, 16 (32.0%) were females and 38 (76.0%) had MB leprosy. Overall, a mean case detection of 28.1 months (95% CI 21.5-34.7) and a median of 21.5 months were observed. Conclusion The three PEP4LEP study districts remain highly endemic, with long case detection delays observed that increase the risk of disabilities and contribute to ongoing leprosy transmission. Integrating activities such as contact screening and provision of post-exposure prophylaxis are therefore a necessary strategy in these endemic areas