[HTML][HTML] Effect of diagnostic and treatment delay on the risk of tuberculosis transmission in Shenzhen, China: an observational cohort study, 1993–2010

S Cheng, W Chen, Y Yang, P Chu, X Liu, M Zhao… - PLoS …, 2013 - journals.plos.org
S Cheng, W Chen, Y Yang, P Chu, X Liu, M Zhao, W Tan, L Xu, Q Wu, H Guan, J Liu, H Liu…
PLoS One, 2013journals.plos.org
Introduction To understand better the risk of tuberculosis transmission with increasing delay
in tuberculosis treatment, we undertook a retrospective cohort study in Shenzhen, China.
Methods 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. Results Among
48,441 pulmonary tuberculosis cases, 70% presented with symptoms of pulmonary TB, 62 …
Introduction
To understand better the risk of tuberculosis transmission with increasing delay in tuberculosis treatment, we undertook a retrospective cohort study in Shenzhen, China.
Methods
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.
Results
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.
Conclusions
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.
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