TB incubation period
â¢ What is the incubation period of tuberculosis? From infection to development of a positive TB skin test reaction (the incubation period) is approximately 2 to 12 weeks. The risk for developing active disease is the highest in the first two years after infection and development of a positive TB skin test reaction.f you are exposed to someone with infectious tuberculosis and have never had a positive reaction to the tuberculin (TB) skin test, you should have a baseline test within 3 months prior to the exposure date.