Pulmonary tuberculosis is a disease that involves the lungs and is often infectious.
All applicants 2 years old or older must have an inteferon gamma release assay (IGRA). Children less than 2 years of age will be tested should there be evidence of contact with TB known or suspected. All applicants with a positive IGRA, known Human immunodeficiency virus (HIV) infection, or signs or symptoms of tuberculosis disease, must have a chest radiograph ( chest x-ray).
Women who are pregnant and have a positive IGRA are required to have a chest x-ray to adjust status.
Applicants with a positive IGRA result and chest x-ray not suggestive of tuberculosis disease, no known HIV infection, and no signs or symptoms of tuberculosis disease have LTBI (latent tuberculosis infection). The civil surgeon can treat these applicants for LTBI or refer them for treatment elsewhere, but the applicants do not have to complete treatment before they are medically cleared and their 1-693 forms are completed, because LTBI is not a Class A condition.
Applicants who have documentation of being diagnosed and completing treatment for LTBI prior to the civil surgeon examination must have a chest x-ray as part of the civil surgeon evaluation. If the chest x-ray is negative, the applicant does not have to be diagnosed with LTBI or reported to the health department and can be classified as "No Class A or Class B TB ".
Some people develop TB disease soon after becoming infected (within weeks) before their immune system can fight the TB bacteria. Other people may get sick years later, with their immune system becoming weak for another reason. Overall, about 5-10 % of infected persons who do not receive treatment for latent TB infection will develop TB disease at some time in their lives. For people whose immune systems are weak, especially those with HIV infection, the risk for developing TB disease is much higher than for people with normal immune systems.