Prevalence of pulmonary tuberculosis in Tibet Autonomous Region, China, 2014

SETTING: Tibet Autonomous Region, China. OBJECTIVES: To determine the prevalence of pulmonary tuberculosis (TB) in Tibet. DESIGN: We conducted a population-based, cross-sectional survey among residents aged >= 15 years in Tibet, China, in 2014. A door-to-door survey was conducted for each randomly selected cluster, followed by a screening interview and a chest X-ray (CXR). Those with symptoms of TB and/or abnormal CXR underwent sputum microscopy testing and culture. RESULTS: Of 31 527 eligible residents, 30 113 (95.5%) participated, 215 of whom were active TB cases, including 49 (22.8%) known cases. Adjusted prevalence of smear-positive, bacteriologically positive and all pulmonary TB cases was respectively 8 (95%CI 62-97), 144 (95%CI 107-152) and 758 (95%CI 662-766) per 100 000 population. This represented a decline of 37% in the prevalence of active cases, and of 21.3% in smear-positive cases compared with a 1990 survey. About 51.3% of bacteriologically positive TB patients in Tibet showed no symptoms. CONCLUSION: We observed a sharp decline in TB prevalence and a low rate of bacteriologically positive cases among all active patients. The low proportion of known cases in the survey reflected possible under-detection by the National TB Programme.