Associated Factors of Mycobacterium Leprae Infection among People with Leprosy in Kwale County

Leprosy, a chronic bacterial disease caused by Mycobacterium leprae, is curable yet neglected. Approximately 200,000 new cases are reported globally each year, with India contributing 60%. In 2020, the African WHO regions had a leprosy burden of 14.9 per 1,000,000 population. Despite maintaining the global elimination target of <1/10000 population, Kenya reported a six-fold increase in cases from 2011 to 2021, with Kwale County contributed 24.3%. This study aimed to determine the factors associated with m. leprae infection.

We conducted a 1:3 case-control study in the Kwale County from June-September, 2023. Case was any person who was diagnosed from any health facility and documented in the Leprosy register, including patients who recently completed treatment. Controls were defined as any person with no clinical signs and were a neighbor to a case, matched by residence, age group, and sex. Questionnaires were administered to both groups. Descriptive analysis was performed for continuous and categorical variables. Factors associated with Leprosy were evaluated using multivariable binary logistic regression. Stepwise backward elimination was used to build a final model; p-values of ≤0.05 were considered statistically significant. A total of 65 cases and 195 controls were enrolled. The mean age was 55 years (SD ± 16) for the cases and 54 years (SD ± 15) for the controls (range:10-83 years). Among cases,56.6% (n = 37) were married, compared to 71.1% (n = 139) of controls. 55% (n = 36) of the cases and 41% (n = 81) of the controls were illiterate. Independent risk factors:family size ≥5 members (aOR=6.99, 95% CI: 2.71-18.06), family contact (aOR=4.33, 95% CI: 2.18-8.58), social contact (aOR=2.24,95% CI 1.16-4.32), and missing of a BCG vaccination mark (aOR=2.24,95% CI: 1.11-4.53).

Large family size, family and social contacts, and missing BCG vaccination mark were associated with Leprosy.The Ministry of Health should sustain and expand BCG vaccination coverage among all eligible populations.