Screening for tuberculosis infection and disease.

Screening is a health-related activity which has clear indications and guidelines which must be followed when this activity is carried out. Methods for screening for tuberculosis infection and disease are available and have been evaluated. Most of the criteria for screening are relevant to tuberculosis. However, screening for tuberculosis disease is not efficient and is not recommended for routine practice. Screening for purposes of preventing tuberculosis disease on the other hand, is efficient and may be indicated where the probability of disease is high and where preventive chemotherapy is included as an integral component of the activity. Such screening utilizes the tuberculin skin test, the chest radiograph and cultures of Mycobacterium tuberculosis. This allows the identification of groups of the population at sufficient risk of developing tuberculosis in future to warrant preventive chemotherapy. In setting guidelines for the use of preventive chemotherapy, the potential harmful effects of such treatment must be carefully considered. Screening without the use of preventive chemotherapy is unethical.