Characterization of geographic mobility among participants in facility- and community-based tuberculosis case finding in urban Uganda

Abstract

Background International and internal migration are recognized risk factors for tuberculosis (TB). Geographic mobility, including travel for work, education, or personal reasons, may also play a role in TB transmission, but this relationship is poorly defined. We aimed to define geographic mobility among participants in facility- and community-based TB case finding in Kampala, Uganda, and to assess associations between mobility, access to care, and TB disease. Methods We included consecutive individuals age ≥15 years diagnosed with TB disease through either routine health facility practices or community-based case finding (consisting of door-to-door testing, venue-based screening, and contact investigation). Each case was matched with one (for community-based enrollment) or two (health facility enrollment) TB-negative controls. We conducted a latent class analysis (LCA) of eight self-reported characteristics to identify and define mobility; we selected the best-fit model using Bayesian Information Criterion. We assessed associations between mobility and TB case status using multivariable conditional logistic regression. Results We enrolled 267 cases and 432 controls. Cases were more likely than controls to have been born in Kampala (p<0.001); there was no difference between cases and controls for remaining mobility characteristics. We selected a two-class LCA model; the “mobile” class was perfectly correlated with a single variable: travel (>3 km) from residence ≥2 times per month. Mobility was associated with a 28% reduction in odds of being a TB case (adjusted matched odds ratio 0.72 [95% confidence interval 0.49, 1.06]). Conclusion Frequency of out-of-neighborhood travel is an easily measured variable that correlates closely with predicted mobility class membership. Mobility was associated with decreased risk of TB disease; this may be in part due to the higher socioeconomic status of mobile individuals in this population. However, more research is needed to improve assessment of mobility and understand how mobility affects disease risk and transmission.

Sociological variety and the transmission efficiency ofMycobacterium tuberculosis: a secondary analysis of qualitative and quantitative data from 15 communities in Zambia

“…The addition of pathogen genomic data might help generate or eliminate hypotheses on transmission location or context, and recent research illustrates that quantitative measures of geographic mobility could be applied to studies of social permeability. 37 Whole genome sequencing may clarify whether importation is more or less relevant in certain communities and highlight transmission chains.…”

Prevalence of pulmonary tuberculosis among casual labourers working in selected road construction sites in central Uganda

“…For example, miners have been reported to have a TB incidence ranging between 2.8% and 12.4% [7][8][9][10][11]. Casual labourers involved in the crushing and grading of aggregates from hard cores (rocks), excavation of gravel (murram) and sorting of gravel (murram), among others, are exposed to high amounts of silica dust [11,12].…”

Geographic mobility and treatment outcomes among people in care for tuberculosis in the Lake Victoria region of East Africa: A multi-site prospective cohort study

“…In the Lake Victoria region, HIV-focused studies have discussed the movements of people around the lake [19][20][21][22][23][24][25][26], and an association between mobility and missed HIV clinic visits has been reported [22]. Among people with TB, much of the existing mobility-related research has focused on migrants' risk of acquiring or transmitting TB [27,28]. Little is known about mobility among people on TB treatment or the impact of mobility on treatment outcomes.…”