Incorporating Household Structure into a Discrete-Event Simulation Model of Tuberculosis and HIV

Human immunodeficiency virus (HIV) increases the risks of developing tuberculosis (TB) disease following infection, and speeds up disease progression. This has had a devastating effect on TB epidemics in sub-Saharan Africa, where incidence rates have more than trebled in the past twenty years. Current control methods for TB disease have failed to keep pace with this growth, and there is an urgent need to find TB control strategies that are effective in high-HIV prevalent settings. This article describes a discrete-event simulation model of endemic TB that includes the effects of HIV and of household structure on the transmission dynamics of TB. Incorporating a social structure allows us to compare the effectiveness of contact-tracing interventions with case-finding targeted at high risk groups. We describe the modeling of the household structure in some detail, as this has applications to the modeling of other infectious diseases.