The HomeACF Study: A household cluster randomised trial of case-finding and intensive prevention for HIV and TB

Tuberculosis and remains a major public health priority in South Africa and other high HIV prevalence countries. Current TB control strategies in Africa have shown limited effectiveness in achieving the rapid reductions in TB incidence required of new global strategies. Previous studies have shown that rates of undiagnosed TB and HIV are high in household contacts of TB cases, making them a priority group for individual and public health action to improve health and reduce infection spread. We therefore propose to investigate the effectivness and cost-effectiveness of a strategy based around intensive screening, prevention and supported access to care for the household contacts of TB patients diagnosed in health facilities in two provinces of South Africa. Rates of new TB, and previously undiagnosed TB and HIV in households randomly allocated to receive the intensive screening, prevention and access to care intervention will compared to households allocated to receive an enhanced standard of care intervention comprising of referral letters and follow-up telephone calls. Study results will help inform strategies to improve TB control in the region.

Tuberculosis transmission occurs predominantly indoors, often at home. We propose this trial to assess whether an improved and intensified household intervention for household contacts of TB cases prevents TB infection and disease in two different TB burden settings. Households of index TB cases diagnosed in health facilities in the North West and Limpopo Provinces of South Africa will be randomly allocated to receive either an enhanced standard of care contact tracing strategy using referral letters with follow-up phone calls, or an intensified contact tracing and treatment support intervention comprising of: sputum Xpert screening for all household contacts and culture for symptomatic individuals;HIV testing and supported linkage to ART; and TB preventive therapy for HIV-positive and TST negative HIV-negative contacts. The primary outcome will compare between groups TB-free survival between months 3-15 after index case recruitment. Secondary outcomes will compare prevalence of MTB infection in children, prevalence of undiagnosed HIV and TB, cohort outcomes, and cost-effectivenes.