Mobility patterns of index tuberculosis cases and tuberculosis transmission niches in Kampala

Abstract

Introduction: TB control relies on minimizing transmission from infectious to susceptible individuals. In Uganda, Kampala faces significant TB challenges, with index cases playing a key role in disease spread. Understanding the mobility patterns of these cases is crucial for effective TB prevention and control. This study assesses the mobility patterns and potential transmission niches of index TB cases in Kampala city. Methods: A cross-sectional study analyzed secondary data of index TB cases from the Mapping Tuberculosis Transmission Study (MATTs) at baseline, which was conducted in Kampala from 2019 to 2023. MATTs focused on baseline, month 2, and month 6 follow-up visits by the index TB cases. Descriptive statistics summarized socio-demographic and clinical factors in this study. Box plots and a mixed-effects negative binomial model assessed factors associated with mobility patterns, with statistical significance set at p = 0.05. Results: Out of 298 index TB cases, 68.5% were male with a median age of 31 (IQR: 26–39). The majority were aged 31-45 (39.9%). About 48.3% were married, 58.7% had primary education, and 52% reported household incomes above 54 USD. Economic venues were the most visited (40.60%), transportation (18.01%), then social venues (15.74%). Females were 11% less likely than males to visit more locations [adjusted prevalence risk ratio =0.89, 95% CI: 0.83–0.95]. Index TB cases aged 24-30 years were 11% more likely [adjusted prevalence risk ratio =1.11, 95% CI: 0.99–1.21] to visit more places than those aged 18-23 years. Conclusion: Age, sex, and treatment history significantly influence index TB cases' mobility, with younger index TB cases and males with a higher likelihood of visiting more places, and those with treatment history had decreased mobility. Recommendations: To effectively reduce TB transmission risks, it is recommended to target mostly visited locations by highly mobile groups through enhanced screening and education in economic and transportation places with improved monitoring for individuals in the 24-45 age group.