Setting: Zimbabwe.
Objective: To investigate the determinants of multidrug-resistant tuberculosis (MDR-TB) among previously treated TB patients.
Design: A 1:3 case-control study with bivariate analysis and logistic regression.
Results: Risk factors for MDR-TB were history of nursing an MDR-TB patient (adjusted OR [aOR] 4.46, 95%CI 2.02-9.88), history of hospitalisation for 3 days (aOR 2.91, 95%CI 1.62-5.23) and history of foreign travel and stay outside Zimbabwe (aOR 2.68, 95%CI 1.46-4.91). Protective factors were previous successful treatment (aOR 0.05, 95%CI 0.02-0.11), history of supervision by a health worker/village health worker (aOR 0.34, 95%CI 0.19-0.60) and having been treated not more than once previously for TB (aOR 0.18, 95%CI 0.08-0.38). No association between human immunodeficiency virus (HIV) infection and MDR-TB (aOR 1.00, 95%CI 0.53-1.88) was observed. However, among HIV-infected patients, those with CD4 <200 cells/mm3 were more likely to develop MDR-TB (aOR 4.62, 95%CI 2.49-8.53).
Conclusion: Individual, service-related, social and demographic factors interact to determine multidrug resistance among previously treated TB patients. Infection control, treatment adherence, reduction of side effects and drug susceptibility testing must be strengthened to reduce the MDR-TB burden in Zimbabwe.