Evidence of hidden leprosy diagnosed by active case finding in a highly endemic setting in Colombo district, Sri Lanka

Background: To achieve the elimination of leprosy by 2030, improving case detection, contact tracing and early treatment is essential. However, the extent of hidden leprosy in pockets of endemic areas remains unexplored.

Objective: To determine the prevalence of hidden leprosy and its associated factors.

Methods: A household survey was conducted in the Divisional Secretariat (DS) area, Moratuwa over two months from 1st September 2023 using an interviewer-administered questionnaire. The data collection and screened were done by the public health staff attached to the Medical Officer of Health office after obtaining the written informed consent.

Results: The socio-demographic data were presented as frequency distributions. The prevalence was calculated and presented as proportion with its 95% confidence interval (CI). The factors associated with leprosy were calculated using bivariate and multivariate logistic regression and p<0.05 was considered statistically significant. A total of 6486 people were screened in 2059 premises. Thirteen cases were confirmed as leprosy; thus, the prevalence of hidden leprosy was 20.1 (95% CI 11-34) per 10000 population. The majority (n=10, 77.0%) were multi-bacillary type, and two patients were under 15 years of age, while three were presented with grade II disability. Age above 15 years (p=0.001) and presence of another leprosy patient in the house (p=0.001) were statistically significant with the disease.

Conclusion: High number of leprosy cases were hidden in pockets in DS area Moratuwa, therefore active case findings targeting populations of age 15 years or above and contact screening of the household/d members play a substantial role.