Pulmonary tuberculosis (TB) is a contagious bacterial infection that mainly involves the lungs, but may spread to other organs.
TB; Tuberculosis - pulmonary
Pulmonary tuberculosis (TB) is caused by the bacteria Mycobacterium tuberculosis (M. tuberculosis). You can get TB by breathing in air droplets from a cough or sneeze of an infected person. This is called primary TB.
In the United States, most people will recover from primary TB infection without further evidence of the disease. The infection may stay asleep or nonactive (dormant) for years. However, in some people it can reactivate.
Most people who develop symptoms of a TB infection first became infected in the past. However, in some cases, the disease may become active within weeks after the primary infection.
The following people are at higher risk for active TB:
Your risk of contracting TB increases if you:
The following factors may increase the rate of TB infection in a population:
In the United States, there are approximately 10 cases of TB per 100,000 people. However, rates vary dramatically by area of residence and socioeconomic class.
See also: Disseminated tuberculosis
The primary stage of the disease usually doesn't cause symptoms. When symptoms of pulmonary TB occur, they may include:
Other symptoms that may occur with this disease:
Examination may show:
Tests may include:
The goal of treatment is to cure the infection with drugs that fight the TB bacteria. Treatment of active pulmonary TB will always involve a combination of many drugs (usually four drugs). All of the drugs are continued until lab tests show which medicines work best.
The most commonly used drugs include:
Other drugs that may be used to treat TB include:
You may need to take many different pills at different times of the day for 1 year or longer. It is very important that you take the pills the way your health care provider instructed.
When people do not take their tuberculosis medications as recommended, the infection becomes much more difficult to treat. The TB bacteria may become resistant to treatment, and sometimes, the drugs no longer help treat the infection.
When there is a concern that a patient may not take all the medication as directed, a health care provider may need to watch the person take the prescribed drugs. This is called directly observed therapy. In this case, drugs may be given 2 or 3 times per week, as prescribed by a doctor.
You may need to be admitted to a hospital for 2 - 4 weeks to avoid spreading the disease to others until you are no longer contagious.
Your doctor or nurse is required by law to report your TB illness to the local health department. Your health care team will be sure that you receive the best care for your TB.
You can ease the stress of illness by joining a support group where members share common experiences and problems.
Symptoms may improve in 2 - 3 weeks. A chest x-ray will not show this improvement until later. The outlook is excellent if pulmonary TB is diagnosed early and treatment is begun quickly.
Pulmonary TB can cause permanent lung damage if not treated early.
Medicines used to treat TB may cause side effects, including liver problems. Other side effects include:
A vision test may be done before treatment so your doctor can monitor any changes in your eyes' health over time.
Call your health care provider if:
TB is a preventable disease, even in those who have been exposed to an infected person. Skin testing (PPD) for TB is used in high risk populations or in people who may have been exposed to TB, such as health care workers.
A positive skin test indicates TB exposure and an inactive infection. Discuss preventive therapy with your doctor. People who have been exposed to TB should be skin tested immediately and have a follow-up test at a later date, if the first test is negative.
Prompt treatment is extremely important in controlling the spread of TB from those who have active TB disease to those who have never been infected with TB.
Some countries with a high incidence of TB give people a BCG vaccination to prevent TB. However, the effectiveness of this vaccine is controversial and it is not routinely used in the United States.
People who have had BCG may still be skin tested for TB. Discuss the test results (if positive) with your doctor.
Iseman MD. Tuberculosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 345.