Determinants of multidrug-resistant tuberculosis (MDR-TB) in South Africa

Abstract

Objectives: Multidrug-resistant tuberculosis (MDR-TB), a global public health threat, is established throughout South Africa following a serious escalation of TB compounded by the HIV epidemic. A national MDR-TB prevalence survey incorporating HIV testing was conducted to establish provincial estimates of MDR-TB prevalence and identify associated risk factors.
Design: Cross-sectional population-based survey involving TB diagnostic centres as primary sampling units in a multistage stratified cluster design employing PPS sampling.
Setting: Primary health care setting in the nine Provinces of South Africa.
Subjects: Demographic details and treatment history were obtained in structured interviews of 5866 culture-confirmed TB patients. Sputum specimens from these patients underwent unlinked HIV testing.
Outcome measures: Estimates of anti-TB drug resistance prevalence, with multiple logistic regression models elucidating risk factors for MDR-TB.
Results: HIV co-infection rate was 55% (range 28-72%). Low MDR-TB prevalence of 2.9% overall (1.6% in new cases; 6.7% in retreatment cases) translates into at least 6000 MDR-TB patients per year. MDR-TB risk factors included previous TB treatment, poor treatment outcome (default or failure), hospitalisation, and HIV infection.
Conclusions: A multi-faceted approach, including HIV treatment programmes and appropriate infection control, is required to avert a large-scale MDR-TB epidemic.