Impact of Different Tuberculosis History at the Onset of Future Multidrug-Resistant Tuberculosis: A Large, Retrospective, Population-Based Cohort Study.

Objectives: The impact of tuberculosis (TB) history on the risk of multidrug-resistant tuberculosis (MDR TB) is not yet fully understood. We aimed to identify the impact of different TB history at the onset of future MDR-TB. Methods: A large, retrospective, population-based cohort study was performed between 2005 and 2019. A multivariable Cox model was used to evaluate independent risk factors for MDR-TB for individuals with different previous TB history (PTBH), such as newly diagnosed TB history (NDTH) and re-treated TB history (RTH). Results: Overall, 12 172 individuals with PTBH were included in this study. The main impacts of different PTBH at the onset of future MDR-TB were as follows: (a) low family income, high-risk occupation, TB patients with severe infection, extended or shortened treatment course, 2H3R3Z3E3/4H3R3 and frequency of sputum culture were significantly linked to incident MDR-TB only in individuals with NDTH (P < 0.05); (b) passive mode of TB case finding, individualised treatment regimens, 3HRZES/6HRE, duration of pulmonary cavities, excellent frequency of chest X-ray examination and duration of negative sputum smear were significantly associated with incident MDR-TB only in individuals with RTH (P < 0.05); (c) age <60 years, history of direct contact, human immunodeficiency virus (HIV) infection, unsuccessful treatment and duration of positive sputum culture were related to incident MDR-TB in both categories of PTBH individuals (P < 0.05). Conclusion: Early and differential surveillances, assessments and interventions for reducing the risk of MDR-TB among individuals with different PTBH play a key role. (c) 2020 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).