Is Tuberculosis (TB) Contagious?

Tuberculosis (TB) is a disease (bacterial infection) caused by a bacterium named Mycobacterium tuberculosis that usually infects the lungs, but in some individuals, the bacteria can attack any part of the body. Before treatments were effective against TB, it was the leading cause of death in the United States.

People may suspect they have tuberculosis if they have spent any length of time around coughing or sneezing individuals known to have tuberculosis. Symptoms and signs of TB include the following:

• Severe coughing lasting at least three weeks or more
• Night sweats
• Coughing up blood or sputum
• Chest pains
• Fatigue
• Weight loss with no appetite
• Fever and chills

A physician can order skin tests, TB blood tests, and send sputum samples for specialized stains and culture to definitively diagnose tuberculosis in an individual.

TB spreads when the organisms are coughed up or aerosolized by sneezing, speaking, or singing. The U.S. Centers for Disease Control and Prevention (CDC) states that TB is not spread by handshakes, sharing food, drinks, or toothbrushes, touching items like toilet seats, clothing, or bedsheets, or kissing. People with other health problems like diabetes, HIV infection, drug abuse, alcohol abuse, and/or recent exposure to individuals with TB are at increased risk for contracting TB.

The incubation period for tuberculosis is measured from exposure time to time of development of a positive tuberculin skin test. In most individuals, the incubation period varies from approximately two to 12 weeks. However, the risk of developing the active disease is highest in the first two years after infection and the development of a positive TB skin test.

Treatment for tuberculosis, both active infections, and latent TB infections involves the use of several different anti-TB medications (for example, isoniazid [Nydrazid, Laniazid, INH], rifampin [Rifadin], rifapentine [Priftin], ethambutol [Myambutol], pyrazinamide), often in combination, for up to a total of six to nine months. A physician will determine the best treatment for you on an individual basis since some strains of the bacteria are resistant to certain drugs.

Some people are probably noncontagious after two weeks while on medication or during treatment but some researchers suggest that others may take longer (months) until they are not able to spread the disease. The reduction or absence of symptoms and signs suggests that a person on antibiotics is unlikely to be contagious, but this is not always true.

Tuberculosis, like many diseases, is best treated early in the infection. Consequently, you should contact a physician if:

• you have been exposed to someone with active TB;
• you have had a positive TB skin test;
• you have developed symptoms of a severe cough with blood-tinged or bloody sputum;
• you have other symptoms of TB, such as fatigue, fever, or night sweats along with coughing;
• your condition worsens with treatment;
• you have symptoms of yellowing of the skin and whites of the eyes (jaundice) while undergoing treatment;
• your vision changes, such as developing blurry or odd-colored vision.

An individual should not put off seeing a physician if there's the slightest chance he or she has TB because the disease can progress and eventually cause death if not treated in a timely fashion.