High burden of prevalent tuberculosis among previously treated people in Southern Africa suggests potential for targeted control interventions

Several studies from Southern Africa report a high risk of tuberculosis (TB) among individuals who have previously been treated for the disease compared to those never before treated [1–5]. In high-burden settings, recurrent TB may affect large numbers of individuals even after successful treatment, with exogenous reinfection as an important underlying mechanism [2–4]. For example, in Cape Town, South Africa, a city with a high incidence of TB, previously treated individuals constitute one-third of the burden of notified TB [6]. High TB prevalence in previously treated people suggests potential for targeted interventions in high-burden settings <http://ow.ly/ihG83015s4l> We would like to thank the ZAMSTAR study team, in particular, Ab Schaap (London School of Hygiene and Tropical Medicine, London, UK), Rory Dunbar (Stellenbosch University, Tygerberg, South Africa) and those involved in the prevalence surveys. We are grateful to those who agreed to participate in the surveys. We thank the City of Cape Town Health Dept, and the Provincial and National Tuberculosis Programs of South Africa and Zambia for their support.