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A systematic review of the investigation and management of close contacts of tuberculosis in China.

BACKGROUND
Contact investigation is a logical approach to intensified case finding in China. However, currently there are no written national guidelines. The aim of this study is to review the published literature that describes the procedures followed by local level and report the yield for active tuberculosis (TB) cases.


METHODS
Studies conducted in China and published between 1997 and 2007 on contact investigation were searched.


RESULTS
Twelve studies were included in the review. There was no standard definition of contact and no study provided details on how to prioritize contacts. Investigation methods vary between each study. The number of contacts investigated per index case ranged from 22.7 to 658 in congregate settings and from 1.5 to 5.8 in household. The yields for active TB ranged from 0 to 11.765% in congregate settings and from 0 to 6.897% in household. The weighted yields for smear-positive index and smear-negative index were 1 and 0.2% respectively in household and 0.5% for pulmonary case index in congregate settings.


CONCLUSION
There is considerable heterogeneity amongst the methods used and the cases yielded in these studies, and in general the quality of contact investigation is low; therefore, there is a need for China to develop national guidelines on contact investigation.