Infection and Drug Resistance (Sep 2022)
Whole-Genome Sequencing and Epidemiological Investigation of Tuberculosis Outbreaks in High Schools in Hunan, China
Abstract
Zuhui Xu,1,2,* Haican Liu,3,* Yanping Liu,4,* Yi Tang,2 Yunhong Tan,2 Peilei Hu,2 Chuanfang Zhang,2 Chongguang Yang,4 Kanglin Wan,3 Qiaozhi Wang2 1Xiangya School of Public Health, Central South University, Changsha, 410078, People’s Republic of China; 2Tuberculosis Control Institute of Hunan Province, Changsha, 410013, People’s Republic of China; 3State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, People’s Republic of China; 4School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518000, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qiaozhi Wang, Department of Institute office, Tuberculosis Control Institute of Hunan Province, No. 519 of Xianjiahu Road, Changsha, 410013, People’s Republic of China, Tel/fax +86073188809748, Email [email protected] Kanglin Wan, State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, No. 155 of Changbai Road, Changping District, Beijing, 102206, People’s Republic of China, Tel +86 13910065264, Email [email protected]: Tuberculosis (TB) seriously threatens individual and public health. Recently, TB outbreaks in schools have been reported more frequently in China and have attracted widespread attention. We reported three TB outbreaks in high schools in Hunan Province, China.Methods: When a tuberculosis patient was reported in a school, we carried out field epidemiological investigations, including tuberculin skin testing (TST), chest X-ray (CXR) and laboratory test for all close contacts, and whole-genome sequencing (WGS) analyses to understand the transmission patterns, the causes and the risk factors for the outbreaks, thereby providing a foundation for the control of TB epidemics in schools.Results: A total of 49 students with TB patients were identified in the three schools where TB outbreaks occurred, including nine patients in School A, 14 patients in School B, and 26 patients in School C. In Schools A, B and C, the putative attack rates in the classes of the index case were 13.8% (8/58), 7.6% (5/66), and 40.4% (21/52), while the putative attack rates of expanding screening in the school were 0.3% (1/361), 0.2% (9/3955), and 0.2% (5/2080), respectively. Thirteen patients had patient delay, with a median delay interval of 69 days (IQR 30.5– 113 days). Twelve patients had a healthcare diagnostic delay with a median delay interval of 32 days (IQR 24– 82 days). Phylogenetic analysis of culture-positive patients revealed that most of them shared a small genetic distance (≤ 12 SNPs), with three separate genetic clusters (including one MDR-TB genomic cluster), indicating the recent transmission of Mycobacterium tuberculosis strains.Conclusion: This combination of field investigation and WGS analysis revealed the transmission of three TB outbreaks in schools. Reinforced implementation is needed to improve timely case finding and reduce diagnosis delay in routine TB control in the school population.Keywords: tuberculosis outbreak, high school, epidemiological investigation, whole genome sequencing
