Recurrent pulmonary tuberculosis after treatment success: a population-based retrospective study in China

Objectives Post-treatment recurrence remains a challenge for the global control of tuberculosis (TB). This study investigated longitudinal data on pulmonary TB recurrence rates and risk factors for recurrence among successfully treated smear-positive tuberculosis cases in China. Methods Between 1st January 2009 and 31st December 2016 we evaluated 33 441 treatment-naïve patients diagnosed with sputum-smear-positive, non-multidrug-resistant TB in Hangzhou, China. We included the data of 9828 patients with TB who were treated successfully. Results A total of 4.9% of the cases were recurrent (479/9828), identified within a median observation period lasting 1565 days. Altogether, 51.1% (245/479) of the recurrences occurred within 1 year. The cumulative 2- and 5-year recurrence rates were 3.90% (95% confidence interval (CI) 3.3-4.5%) and 5.4% (95%CI 4.8-6.0%), respectively. Prolonged treatment (over 7 months) occurred in 64.7% (6363/9828), with a median treatment duration of 242 days (interquartile range 195-348 days). Male sex (adjusted hazard ratio (aHR) (95%CI) 1.61 (1.30-2.00), p Conclusions Recurrence remains a problem for successfully treated patients with sputum-smear-positive pulmonary TB, especially those with independent risk factors. Further analysis of prolonged treatment is required.