Tuberculosis in travellers.

Tuberculosis (TB) incidence is increasing in many countries which are popular with international travellers. The development of active TB is a two-stage process; the risk of acquiring new TB infection depends primarily on the risk of contact with an individual with infectious TB, and the risk of disease on the immune status of the newly infected person. The risk of TB infection is low for most holiday-makers, but among long-term travellers to countries with high TB incidence, the risk may be similar to that experienced by the local population (0.5-2.5% per year); the risk to people working in health care is particularly high. Effective pre-travel advice involves assessing the traveller's risk of TB infection and disease. Recommendations on the prevention of TB in travellers vary between countries. Possible strategies include avoidance of exposure; BCG vaccination; and tuberculin skin testing before and after travel, with preventive therapy for those whose post-travel skin tests indicate recent infection. For those at highest risk of progression to disease, there may be value in preventive therapy during travel to reduce the risk of new TB infection. Further information on the contribution of recent travel to incident TB in industrialised countries would be valuable.