Causes of latent tuberculosis

Tuberculosis bacteria spread through the air from a person with active tuberculosis of the lungs or throat. After inhalation, the immune system may contain the bacteria in the body. A person with latent infection usually has no symptoms and does not pass tuberculosis to others. The infection can become active later if immune protection weakens. HIV infection and some immune-suppressing medicines or illnesses can increase concern, so clinicians consider medical history as well as exposure. A positive test does not by itself show whether infection is latent or active.

Arrange a clinical assessment rather than assuming that a positive result means active disease. Tuberculosis screening may involve a skin or blood test, questions about exposure, and an examination. A chest X-ray may help check for signs of disease in the lungs, although the clinician decides which tests are needed. Take prescribed preventive treatment exactly as directed and report troublesome effects promptly. Keep follow-up appointments so the plan can be adjusted safely.

Seek prompt medical advice for a persistent cough, fever, night sweats, unexplained weight loss, chest pain, breathlessness, or swollen glands after a tuberculosis exposure or positive test. Urgent help is needed for severe breathing difficulty, coughing blood, confusion, or marked weakness. These symptoms can have several causes, but they need assessment because they may indicate active infection or another significant illness.

Ask when exposure may have occurred, whether the result needs confirmation, which tests will distinguish latent from active infection, and how treatment will be monitored. Tell the clinician about HIV, pregnancy, liver problems, and every medicine or supplement you take.