Primary Infection

• In most individuals with competent immune systems, the immune response would stop the replication of M. tuberculosis, leaving some bacilli dormant (latent TB infection).
• In some cases, the immune response may not be adequate enough to prevent replication of M. tuberculosis and primary TB disease develops within a few weeks or months.
• Although primary TB may be severe and disseminated, it is not generally associated with high-level transmissibility. Reinfection or repeat infection in a person who has already had a primary infection is still considered primary TB.