Role of Mobility and Health Disparities on the Transmission Dynamics of Tuberculosis

TL;DR

This study models TB transmission considering mobility and health disparities between regions, revealing that strategic movement of infected individuals can potentially reduce overall TB prevalence.

Contribution

It introduces a simplified two-patch model incorporating short-term mobility and varying reinfection rates to better understand TB dynamics across regions.

Findings

Mobility patterns influence TB transmission and control outcomes.

Infected individuals moving from high to low prevalence areas can reduce overall TB prevalence.

Effective population size and residence time distribution are key factors in TB spread.

Abstract

The transmission dynamics of Tuberculosis (TB) involve complex epidemiological and socio-economical interactions between individuals living in highly distinct regional conditions. The level of exogenous reinfection and first time infection rates within high-incidence settings may influence the impact of control programs on TB prevalence. This study aims at enhancing the understanding of TB dynamics via the study of scenarios, within {\it simplified}, two patch, risk-defined environments, in the presence of short term mobility and variations in reinfection and infection rates. The modeling framework captures the role of individuals' `daily' dynamics within and between places of residency, work or business via the proportion of time spent in residence and as visitors to TB-risk environments (patches). As a result, the {\it effective population size} of Patch $i$ (home of $i$-residents) at time $t$ must account for visitors and residents of Patch $i$, at time $t$. The impact that {\it effective population size} and the distribution of {\it individuals' residence times} in different patches have on TB transmission and control are studied using selected scenarios where risk is defined by the estimated or perceive first time infection and/or exogenous re-infection rates. Our results suggest that, under certain conditions, allowing infected individuals to move from high to low TB prevalence areas (for example via the sharing of treatment and isolation facilities) may lead to a reduction in the total TB prevalence in the overall, here two-patch, population.