Mobility patterns, activity locations, and tuberculosis in Nairobi, Kenya

Background: Annually, over 3 million people develop TB but are not diagnosed and treated. We aimed to characterize the mobility patterns and activity locations of people with TB in an urban, high burden setting to inform future active case finding (ACF) efforts. Methods: We conducted a population based TB prevalence survey in Nairobi, Kenya, in 2022. Participants aged 15 years or older with TB symptoms or a suggestive chest x-ray submitted sputum for Xpert Ultra and culture. We collected data on individual activity locations and mobility and evaluated their association with the risk of pulmonary TB. Results: The prevalence survey enrolled 6369 participants across nine clusters. There were significant differences in mobility patterns and activity locations between sexes and age groups. Mobility factors were not significantly associated with TB. In the adjusted analysis, age group 45 to 54 (OR 2.45), male sex (OR 2.95), and use of a social activity location (OR 1.96) were significantly associated with a higher risk of TB. Conclusions: We did not find a significant association between mobility patterns and TB but found a positive association between reported "social" activity locations and TB. Identification of "social" activity locations, particularly bars, provides important insight into possible venues for spatially targeted ACF activities.