Piloting the feasibility of a population-based joint TB-HIV survey in KwaZulu-Natal Province, South Africa, 2019

Abstract

South Africa bears a high burden of infectious diseases, including intersecting epidemics of human immunodeficiency virus (HIV) and tuberculosis (TB). Among people living with HIV, TB is the predominant cause of death. Since 2002, South Africa has conducted six national population-based HIV surveys, and its first national TB prevalence survey between 2017 and 2019. Given the epidemiologic overlap of these conditions and dwindling resources, a joint national TB and HIV survey could be advantageous. We piloted a joint survey design in August-September 2019 to assess the feasibility of simultaneously collecting HIV and TB data. The pilot survey utilized the same sampling frame as the 2017-2019 national TB prevalence survey, based on small area layers as building blocks for clusters. Two clusters in KwaZulu-Natal (one urban and one rural) were selected. People of all ages were eligible to participate. Household questionnaires were administered to consenting household heads, followed by invitations to the cluster survey hub, where age-appropriate individual questionnaires were administered. Whole blood samples were tested for HIV, viral load, HIV drug resistance and HIV recent infection status. TB metrics included symptom and chest x-ray screening with sputum testing for those screening positive. Those ≥18 years received other health measurements (weight, height) and screening tests (random blood glucose, cholesterol). The survey successfully combined the collection of both HIV and TB relevant data. Overall, Household-level uptake was 78.6% (363/462), while individual-level uptake at the hub was 48.1% (616/1,280), with lower participation in the urban cluster. Uptake of additional health measurements exceeded 87%. The pilot study demonstrated that combining TB and HIV surveys is possible, but fewer people participated compared to the individual national HIV and TB surveys. Further operational research could explore how to optimize survey design, accommodate differing data requirements, and improve participation in future joint surveys.