Is a History of BCG Vaccination a Contraindication for TB Skin Testing?
A history of BCG vaccination is not a contraindication for placing a TB skin test. Persons born in or who have spent time in countries where TB is prevalent, have received BCG, and have never been screened for TB, should receive a TB skin test as a part of any initial medical evaluation. Commonly used in countries with high rates of TB, BCG offers some degree of protection against miliary, bone and joint, and meningeal forms of the disease in infants and young children. However, the protective effect is highly variable and wanes over time. The vaccine can interfere with the interpretation of the TB skin test because it is very difficult to determine whether a positive reaction is due to TB infection or BCG. Many foreign-born persons diagnosed with active TB have a history of BCG vaccination. BCG has not been shown to protect against pulmonary disease, and it does not prevent TB infection from occurring. Since a positive skin test reaction due to BCG is unlikely to persist for more than
