PLoS ONE (Jan 2013)

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

  • Shiming Cheng,
  • Wei Chen,
  • Yingzhou Yang,
  • Ping Chu,
  • Xiaoli Liu,
  • Meigui Zhao,
  • Weiguo Tan,
  • Li Xu,
  • Qingfang Wu,
  • Hongyun Guan,
  • Jinhong Liu,
  • Haitao Liu,
  • Ray Y Chen,
  • Zhongwei Jia

DOI
https://doi.org/10.1371/journal.pone.0067516
Journal volume & issue
Vol. 8, no. 6
p. e67516

Abstract

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IntroductionTo understand better the risk of tuberculosis transmission with increasing delay in tuberculosis treatment, we undertook a retrospective cohort study in Shenzhen, China.MethodsAll 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.ResultsAmong 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 (pConclusionsDelayed 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.