Strategies for halting the rise of multidrug resistant TB epidemics: assessing the effect of early case detection and isolation

Authored by Jane M Heffernan, Aquino L Espindola, Affan Shoukat, Seyed M Moghadas, Marek Laskowski, Marie Varughese

Date Published: 2017

DOI: 10.1093/inthealth/ihw059

Sponsors: National Science and Engineering Research Council of Canada (NSERC)

Platforms: No platforms listed

Model Documentation: Other Narrative Flow charts Mathematical description

Model Code URLs: Model code not found

Abstract

Background: The increasing rates of multidrug resistant TB (MDR-TB) have posed the question of whether control programs under enhanced directly observed treatment, short-course (DOTS-Plus) are sufficient or implemented optimally. Despite enhanced efforts on early case detection and improved treatment regimens, direct transmission of MDR-TB remains a major hurdle for global TB control. Methods: We developed an agent-based simulation model of TB dynamics to evaluate the effect of transmission reduction measures on the incidence of MDR-TB. We implemented a 15-day isolation period following the start of treatment in active TB cases. The model was parameterized with the latest estimates derived from the published literature. Results: We found that if high rates (over 90\%) of TB case identification are achieved within 4 weeks of developing active TB, then a 15-day patient isolation strategy with 50\% effectiveness in interrupting disease transmission leads to 10\% reduction in the incidence of MDR-TB over 10 years. If transmission is fully prevented, the rise of MDR-TB can be halted within 10 years, but the temporal reduction of MDR-TB incidence remains below 20\% in this period. Conclusions: The impact of transmission reduction measures on the TB incidence depends critically on the rates and timelines of case identification. The high costs and adverse effects associated with MDR-TB treatment warrant increased efforts and investments on measures that can interrupt direct transmission through early case detection.
Tags
Agent-based modelling emergence Diagnosis transmission Transmission dynamics Mycobacterium-tuberculosis South-africa Exogenous reinfection Case isolation Exogenous re-infection Multidrug resistant tb Relapse Short-course chemotherapy Pulmonary tuberculosis Dots-plus Mdr-tb