Tuberculosis (TB)

| What is tuberculosis? | Is tuberculosis an infectious and contagious disease that can be treated? | How does a person get TB? | What happens to the body when a person gets TB? | How common is TB and who gets it? | How can I get tested for TB? | How do patients with tuberculosis feel? | How does a doctor diagnose tuberculosis? | How is tuberculosis treated? | What are the side effects of medicines for TB? | Why do I need to take TB medicine regularly? | How can I keep from spreading TB?
 | What is drug-resistant tuberculosis? Can people with drug-resistant tuberculosis be treated? | Can people be vaccinated against tuberculosis? | What is the difference between tuberculosis disease and latent tuberculosis infection? | If I have latent TB infection, how can I keep from developing active TB disease? | What if I have HIV infection? | What's in the future for TB? | What is directly observed therapy? | Tuberculosis At A Glance |

Can people be vaccinated against tuberculosis?

BCG is a vaccine for tuberculosis disease that is used in many countries to prevent deaths and severe TB in infants and children.

In places where TB is not common, such as the United States, BCG use is not generally recommended.

BCG vaccination does not completely prevent people from getting tuberculosis. It may also cause a positive tuberculin skin test and make it difficult to diagnose latent TB.

If you were vaccinated with BCG, you may have a positive reaction to a TB skin test. This reaction may be due to the BCG vaccine itself or due to infection with the TB bacteria. Your positive reaction probably means you have been infected with TB bacteria if

• You recently spent time with a person who has active TB disease; or

• You being to an area of the world where active TB disease is very common (such as most countries in Latin America and the Caribbean, Africa, Asia, Eastern Europe, and Russia)

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What is the difference between tuberculosis disease and latent tuberculosis infection?

There are two common forms of tuberculosis

• latent tuberculosis infection and

• tuberculosis disease

In most people who breathe in TB bacteria and become infected, the body is able to fight the bacteria to stop them from growing. The bacteria become inactive, but they remain alive in the body and can become active later. This is called latent TB infection. People with latent TB infection

• have no symptoms

• don't feel sick

• can't spread TB to others

• usually have a positive skin test reaction

• can develop active TB disease if they do not receive treatment for latent TB infection

Many people who have latent TB infection never develop active TB disease. In these people, the TB bacteria remain inactive for a lifetime without causing disease.

However, they may develop tuberculosis disease in the future. They are often prescribed treatment to prevent the disease from developing.

But in other people, especially people who have weak immune systems, the bacteria become active and cause TB disease.

TB bacteria become active if the immune system can't stop them from growing. The active bacteria begin to multiply in the body and cause active TB disease.

The bacteria attack the body and destroy tissue. If this occurs in the lungs, the bacteria can actually create a hole in the lung. Some people develop active TB disease soon after becoming infected, before their immune system can fight the TB bacteria. Other people may get sick later, when their immune system becomes weak for another reason.

Babies and young children often have weak immune systems. People infected with HIV, the virus that causes AIDS, have very weak immune systems. Other people can have weak immune systems, too, especially people with any of these conditions:

• substance abuse

• diabetes mellitus

• silicosis

• cancer of the head or neck

• leukemia or Hodgkin's disease

• severe kidney disease

• low body weight

• certain medical treatments (such as corticosteroid treatment or organ transplants)

• specialized treatment for rheumatoid arthritis or Crohn’s disease

Symptoms of TB depend on where in the body the TB bacteria are growing. TB bacteria usually grow in the lungs. TB in the lungs may cause symptoms such as

• a bad cough that lasts longer than 2 weeks

• pain in the chest

• coughing up blood or sputum (phlegm from deep inside the lungs)

Other symptoms of active TB disease are

• weakness or fatigue

• weight loss

• no appetite

• chills

• fever

• sweating at night

These persons usually have symptoms of tuberculosis disease. People with tuberculosis disease of the lungs or throat are capable of spreading germs to others. Drugs are prescribed to cure tuberculosis disease in these persons.

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If I have latent TB infection, how can I keep from developing active TB disease?

Many people who have latent TB infection never develop active TB disease. But some people who have latent TB infection are more likely to develop active TB disease than others. These people are at high risk for active TB disease. They include

• people with HIV infection

• people who became infected with TB bacteria in the last 2 years

• babies and young children

• people who inject illegal drugs

• people who are sick with other diseases that weaken the immune system

• elderly people

• people who were not treated correctly for TB in the past

If you have latent TB infection (a positive TB skin test reaction or positive QFT) and you are in one of these high-risk groups, you need to take medicine to keep from developing active TB disease.

This is called treatment for latent TB infection. There are several treatment options. You and your health care provider must decide which treatment is best for you.

The medicine usually taken for the treatment of latent TB infection is called isoniazid (INH).

INH kills the TB bacteria that are in the body. If you take your medicine as instructed by your doctor, it can keep you from developing active TB disease.

Children and people with HIV infection may need to take INH for a longer time.

Because there are less bacteria in a person with latent TB infection, treatment is much easier. Usually, only one drug is needed to treat latent TB infection. A person with active TB disease has a large amount of TB bacteria in the body. Several drugs are needed to treat active TB disease.

Sometimes people are given treatment for latent TB infection even if their skin test reaction is not positive.

This is often done with infants, children, and HIV-infected people who have recently spent time with someone with active TB disease. This is because they are at very high risk of developing active TB disease soon after they become infected with TB bacteria.

It is important that you take all the pills as prescribed. If you start taking INH, you will need to see your doctor or nurse on a regular schedule. He or she will check on how you are doing. Some people have serious side effects from INH. If you have any of the side effects, call your doctor right away:

• no appetite

• nausea

• vomiting

• yellowish skin or eyes

• fever for 3 or more days

• abdominal pain

• tingling in the fingers and toes

Warning: Drinking alcoholic beverages (wine, beer, and liquor) while taking INH can be dangerous. Check with your doctor for more information.

People who have latent TB infection need to know the symptoms of active TB disease. If they develop symptoms of active TB disease, they should see a doctor right away.

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What if I have HIV infection?

A person can have latent TB infection for years. But if that person's immune system gets weak, the infection can quickly turn into active TB disease.

Also, if a person who has a weak immune system spends time with someone with active TB disease, he or she may become infected with TB bacteria and quickly develop active TB disease.

Because HIV infection weakens the immune system, people with latent TB infection and HIV infection are at very high risk of developing active TB disease.

All persons with HIV infection should be tested to find out if they have latent TB infection. If they have latent TB infection, they need treatment as soon as possible to prevent them from developing active TB disease. If they have active TB disease, they must take medicine to cure the disease.

Active TB disease can be prevented and cured, even in people with HIV infection.

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What's in the future for TB?

Conceivably, TB could have been eliminated by effective treatment, vaccinations, and public health measures by the year 2000. However, the emergence of HIV changed the whole picture. Because of HIV, a tremendous increase in the frequency (incidence) of TB occurred in the 80s and throughout the 90s. This increase in TB happened because suppression of the body's immune (defense) system by HIV allowed TB to occur as a so-called opportunistic infection. Hopefully, control of HIV in the future will check this resurgence of tuberculosis.

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What is directly observed therapy?

The best way to remember to take your medicine is to get directly observed therapy (DOT). If you get DOT, you will meet with a health care worker every day or several times a week. You will meet at a place you both agree on. This can be the TB clinic, your home or work, or any other convenient location. You will take your medicine at this place while the health care worker watches.

DOT helps in several ways. The health care worker can help you remember to take your medicine and complete your treatment. This means you will get well as soon as possible. With DOT, you may need to take medicine only 2 or 3 times each week instead of every day.

The health care worker will make sure that the medicine is working as it should. This person will also watch for side effects and answer questions you have about TB.

Even if you are not getting DOT, you must be checked at different times to make sure everything is going well. You should see your doctor or nurse regularly while you are taking your medicine. This will continue until you are cured.

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Tuberculosis At A Glance

Tuberculosis (TB) is an infection, primarily in the lungs (a pneumonia), caused by bacteria called Mycobacterium tuberculosis. It is spread usually from person to person during close contact by breathing infected air.

TB can remain in an inactive (dormant) state for years without causing symptoms or spreading to other people.

When the immune system of a patient with dormant TB is weakened, the TB can become active (reactivate) and cause infection in the lungs or other parts of the body.

The risk factors for acquiring TB include close contact situations, alcohol and IV drug abuse, and certain diseases (e.g., diabetes, cancer, and HIV) and occupations (e.g., health care workers).

The most common symptoms of TB are fatigue, fever, weight loss, coughing, and night sweats.

The diagnosis of TB involves skin tests, chest x-rays, and sputum analysis (smear and culture).

Inactive tuberculosis may be treated with an antibiotic, isoniazid (INH), to prevent the TB infection from becoming active.

Active TB is treated, usually successfully, with INH in combination with one or more of several drugs, including rifampin, ethambutol, pyrazinamide, and streptomycin.

Drug-resistant TB is a serious, as yet unsolved public health problem, especially in Southeast Asia and in prison populations.

The occurrence of HIV has been responsible for an increased frequency of tuberculosis. Control of HIV in the future, however, should substantially decrease the frequency of TB.

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