Prevention of the spread of TB lies primarily in identifying, isolating, and treating those who have it before they pass it on to others.
A vaccine, called BCG (Bacille Calmette-Guérin), is routinely administered in parts of the world where TB is common, although studies have shown that this vaccine will not prevent every case of TB. People who have been vaccinated with BCG will have a positive TB skin test, which eliminates the use of the skin test as an indicator of a recent TB infection. The incidence of TB in the U.S. is low, so U.S. health authorities do not recommend the use of the BCG vaccine.
Early detection depends on identifying those at risk and testing them at regular intervals for latent TB infection. It also depends on recognizing, diagnosing, and treating those who progress to active tuberculosis.
Treatment of Latent TB
People with latent TB may go on to develop an active infection, so they are treated to prevent them from getting TB disease. Currently available treatments for latent TB infection may reduce a person's risk of developing active TB disease by 60-90%.
It is very important to follow the treatment regimen exactly as prescribed to ensure that all of the TB bacteria are killed. With the shorter courses of treatment, people may be more likely to take all their medication and the risk of side effects is reduced.
Once M. tuberculosis has been positively identified, a treatment program that involves taking several different antibiotics for several months will be recommended. The choice of medications and length of treatment will depend on the person's age, overall health, possible drug resistance, and the location of the infection.
People with HIV infection who are diagnosed with active TB may require a unique drug regimen. One of the antibiotics, rifampin, is known to interfere with some of the antiretroviral drugs that are used in the treatment of HIV infection, so a different TB drug may be prescribed.
Although symptoms will often go away after several weeks, it is crucial that the infected person continue to take the drugs for the entire time period prescribed to ensure that all of the TB bacteria are killed. If bacteria remain in the body, the TB can come back (recur). Recurrent infection is more likely to be resistant to the first-line drugs, requiring treatment for several more months with drugs that have more side effects.
The health community strongly recommends that those with active tuberculosis participate in directly observed therapy (DOT). This involves taking the medication each day, or several days a week, under the supervision of medical personnel. This increases patient compliance with treatment and decreases the number of people who have to be treated again because their TB has returned.
Those who have been exposed to or diagnosed with TB that is resistant to one or both of the first-line drugs, rifampin and isoniazid (multidrug-resistant TB, MDR-TB), are prescribed a regimen utilizing second-line drugs.