Mobile targeted screening for tuberculosis in Zimbabwe: diagnosis, linkage to care and treatment outcomes

SETTING: Targeted active screening for tuberculosis (Tas4TB) using mobile trucks in the community was implemented in 15 high TB burden districts in Zimbabwe. At-risk populations were screened for TB based on symptoms and chest radiography (CXR) results. Those with any positive symptom and/or an abnormal CXR had sputum collected for investigation and diagnosis and were linked to care and treatment if found to have TB. OBJECTIVE: To determine 1) the proportion and characteristics of those screened and diagnosed with TB; 2) the relationship between TB symptoms, CXR and diagnostic yields; and 3) the relationship between initiation of anti-TB treatment and treatment outcomes. DESIGN: Cohort study using routinely collected data. RESULTS: A total of 39 065 persons were screened, of whom 663 (1.7%) were diagnosed with TB; 126/663 (19.0%) were bacteriologically confirmed. The highest TB diagnostic yields were in symptomatic persons with CXRs suggestive of TB (19.4%), asymptomatic persons with CXRs suggestive of TB (8.4%) and persons at high-risk of TB (3.2%). For all diagnosed TB patients, pre-treatment loss to follow-up was 18.9% and treatment success was 59.9%. CONCLUSION: Tas4TB resulted in high diagnostic yields; however, linkage of diagnosis to care was poor. Reasons for loss to follow-up need to be better understood and rectified.