Children and adolescents are of particular importance in contact screening, given the high prevalence found in the youngest age groups and the importance of rapid diagnosis and treatment owing to the risk of rapid disease progression in children younger than 5 years(23), as well as the importance of initiating preventive treatment if TB disease has been ruled out (see Section 2.4.2).
Contacts who are persons living with HIV are also of particular importance in contact screening, given their extremely high prevalence of TB disease. Contacts living with HIV are also at increased risk for rapid progression to TB disease, and if they develop it, an increased risk of mortality. Contacts of TB patients who are also living with HIV are at a higher probability of themselves being HIV-positive, even they are unaware of their status. Thus, in settings with a high prevalence of HIV or when the index case is a person living with HIV, or both, all household contacts and close contacts should be offered counselling and testing for HIV. People living with HIV who are household contacts or close contacts of someone with TB disease and who, after an appropriate clinical evaluation, are found not to have TB disease should be evaluated for TPT.