Is the EU model for contact investigation applicable to high TB burden settings?

Contact investigation is the search for secondary cases of tuberculosis (TB) or latent tuberculosis infection (LTBI) among contacts of patients with a transmissible form of TB, usually smear-positive pulmonary disease. The aim is to detect those who have already started developing TB in order to initiate treatment as soon as possible and prevent further transmission of the disease, and also to detect those who have been infected and could benefit from a preventive treatment before the development of TB. The implementation of preventive therapy for persons with the highest risk of developing TB, that is the reduction of the pool of future cases of TB, is now considered one of the activities able to support a decline in the prevalence of TB. This implies that the search for infected contacts and the prevention of TB should be performed in parallel with diagnostic and curative activities. The implementation of screening activities, at least for exposed children and immunocompromised persons, seems to be feasible without unaffordable costs, even in high TB burden settings.