Effect of Diagnostic and Treatment Delay on the Risk of Tuberculosis Transmission in Shenzhen, China: An Observational Cohort Study, 1993-2010

• Published in: PloS one Vol. 8; no. 6; p. e67516
• Main Authors: Cheng, Shiming, Chen, Wei, Yang, Yingzhou, Chu, Ping, Liu, Xiaoli, Zhao, Meigui, Tan, Weiguo, Xu, Li, Wu, Qingfang, Guan, Hongyun, Liu, Jinhong, Liu, Haitao, Chen, Ray Y, Jia, Zhongwei
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.06.2013; Public Library of Science (PLoS)
• Subjects: Adolescent; Adult; Age Factors; Aged; Antitubercular Agents - therapeutic use; Biology; Child; Child, Preschool; China; Chronic illnesses; Cohort analysis; Computer Science; Delay; Delayed Diagnosis; Diagnostic systems; Disease control; Disease prevention; Disease transmission; Female; Health care; Health Knowledge, Attitudes, Practice; Health services; Health surveillance; Humans; Infant; Infant, Newborn; Infections; Male; Medical diagnosis; Medicine; Middle Aged; Mycobacterium tuberculosis - pathogenicity; Observational studies; Patients; Preventive medicine; Public health; Retrospective Studies; Risk; Risk Factors; Smear; Sputum; Sputum - microbiology; Time-to-Treatment; Treatment Outcome; Trends; Tuberculosis; Tuberculosis, Pulmonary - diagnosis; Tuberculosis, Pulmonary - drug therapy; Tuberculosis, Pulmonary - microbiology; Tuberculosis, Pulmonary - transmission; Young Adult; Beijing China; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0067516

To understand better the risk of tuberculosis transmission with increasing delay in tuberculosis treatment, we undertook a retrospective cohort study in Shenzhen, China. All pulmonary tuberculosis cases in the Shenzhen tuberculosis surveillance database from 1993-2010 were included. Sputum smear positivity and presence of pulmonary cavity were used as proxies for risk of tuberculosis transmission. Among 48,441pulmonary tuberculosis cases, 70% presented with symptoms of pulmonary TB, 62% were sputum smear positive, and 21% had a pulmonary cavity on chest x-ray. 95.3% of patients self-presented for evaluation of illness after a median 58 days of delay after symptoms began. The proportion presenting sputum smear positive (p<0.001) and with a pulmonary cavity (p<0.001) increased significantly with increasing duration of delay. Delayed diagnosis and treatment of tuberculosis is associated with a significantly increased risk of pulmonary sputum smear positivity and pulmonary cavity. To decrease risk of transmission, treatment delay needs to be reduced further.