Model of the Effects of Improving TB Diagnosis on Infection Dynamics in Differing Demographic and HIV-Prevalence Scenarios

摘要

This paper seeks to examine the sensitivity of tuberculosis transmission (TB) dynamics to the rate at which infectious individuals with active TB begin a TB treatment course, and therefore cease to be infectious to others. We model this by varying both the rate at which individuals are diagnosed and begin treatment, and the demographic conditions in which the epidemic occurs. An agestructured deterministic ordinary differential equation model is used to study the sensitivity of TB transmission dynamics to the implementation of a more effective diagnostic such as Xpert MTB/ RIF in a high HIV prevalence setting. Sensitivity analysis of the effectiveness of the diagnostic (λ) shows the interim disease dynamics in three demographic scenarios defined by differences in HIV prevalence and age structure at a constant transmission rate. In the near future, we expect the diagnostic to have the most effect in areas of high HIV prevalence. In the long term, we expect the diagnostic to have the most significant impact at high transmission rates regardless of HIV prevalence and age structure.