(BMI) 7 for a one-time mass screening. The strength of
this method is that it is easy to conduct within the
prison, understanding that some individuals with ac-
tive TB will be missed.5
In 2006, the International Standards for Tubercu-
losis Care (ISTC) recommended evaluation of persons
with unexplained productive cough of 2Ð3 weeks
for TB. 8 This standard identiÞes cough 2 weeks as a
single criterion to maximise the identiÞcation of TB
suspects, while recognising the risk of missing cases.
As cough 2 weeks comprised part of the WHO score,
we were able to evaluate this new standard for pul-
monary TB detection in our population. The purpose
of this study was thus 1) to present prevalence of
smear-positive TB from the one-time mass screening
and 2) to compare the yield of smear-positive TB using
the new ISTC recommendation with the yield using our
case-Þnding strategy.
STUDY POPULATION AND METHODS
Setting
The setting for this cross-sectional study was 27 Thai
prisons where the DOTS strategy had been fully im-
plemented. Of the 136 prisons in Thailand, the largest