WHO_HTM_TB_2013_04_7

(a) Systematic screening for active TB may be considered for geographically
defined subpopulations with extremely high levels of undetected TB (1%
prevalence or higher).
(b) Systematic screening for active TB may be considered also for other
subpopulations that have very poor access to health care, such as people
living in urban slums, homeless people, people living in remote areas with
poor access to health care, and other vulnerable or marginalized groups
including some indigenous populations, migrants and refugees.

WHO_HTM_TB_2013_04_6

In settings where the TB prevalence in the general
population is 100/100 000 population or higher, systematic screening for
active TB should be considered among people who are seeking health care or
who are in health care and who belong to selected risk groups.