WHAT IS TB?

Tuberculosis (TB) is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria usually attack the lungs. But TB bacteria can attack any part of the body such as the kidney, spine, and brain. If not treated properly, TB disease can be fatal.

TB is spread through the air from one person to another. The bacteria are put into the air when a person with disease of the lungs or throat coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.
However, not everyone infected with TB bacteria becomes sick. People, who are infected, but not sick, have what is called latent TB infection. People who have latent TB infection do not feel sick, do not have any symptoms, and cannot spread TB to others. But some people with latent TB infection go on to get TB disease.
There is good news. People with TB disease can be treated if they seek medical help. Even better, most people with latent TB infection can take medicine so that they will not develop TB disease.

HOW IS TB SPREAD?

TB is spread through the air from one person to another. The bacteria are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.

When a person breathes in TB bacteria, the bacteria can settle in the lungs and begin to grow. From there, they can move through the blood to other parts of the body, such as the kidney, spine, and brain.
TB disease in the lungs or throat can be infectious. This means that the bacteria can be spread to other people. TB in other parts of the body, such as the kidney or spine, is usually not infectious.
People with TB disease are most likely to spread it to people they spend time with every day. This includes family members, friends, and coworkers or schoolmates.

WHAT IS LATENT TB INFECTION?

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 bacteria to others
• Usually have a positive skin test reaction or positive TB blood test
• May develop TB disease if they do not receive treatment for latent TB infection
Many people who have latent TB infection never develop TB disease. In these people, the TB bacteria remain inactive for a lifetime without causing disease. But in other people, especially people who have weak immune systems, the bacteria become active, multiply, and cause TB disease.

WHAT IS TB DISEASE?

If the immune system can’t stop TB bacteria from growing, the bacteria begin to multiply in the body and cause 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 TB disease soon after becoming infected (within weeks) before their immune system can fight the TB bacteria. Other people may get sick years 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, 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 DISEASE depends on where in the body the TB bacteria are growing. TB disease in the lungs may cause symptoms such as:
• A bad cough that lasts 3 weeks or longer
• Pain in the chest
• Coughing up blood or sputum (phlegm from deep inside the lungs)
Other symptoms of TB disease are:
• Weakness or fatigue
• Weight loss
• No appetite
• Chills
• Fever
• Sweating at night

THE DIFFERENCE BETWEEN LATENT TB INFECTION AND TB DISEASE

A Person with Latent TB Infection A Person with TB Disease
• Does not feel sick • Usually feels sick
• Has no symptoms • Has symptoms that may include:
- a bad cough that lasts 3 weeks or longer
- pain in the chest
- coughing up blood or sputum
- weakness or fatigue
- weight loss
- no appetite
- chills
- fever
- sweating at night
• Cannot spread TB bacteria to others • May spread TB bacteria to others
• Usually has a positive TB skin test or positive TB blood test • Usually has a positive TB skin test or positive TB blood test
• Has a normal chest x-ray and a negative sputum smear • May have an abnormal chest x-ray, or positive sputum smear or culture
• Should consider treatment for latent TB infection to prevent TB disease • Needs treatment for TB disease

SHOULD I GET TESTED FOR TB?

You should get tested for TB if

• You have spent time with a person known or suspected to have TB disease; or

• You have HIV infection or another condition that weakens your immune system and puts you at high risk for TB disease; or

• You have symptoms of TB disease; or

• You are from a country where TB disease is very common (most countries in Latin America and the Caribbean, Africa, Asia, Eastern Europe, and Russia); or

• You live somewhere in the United States where TB disease is more common such as a homeless shelter, migrant farm camp, prison or jail, and some nursing homes; or

• You inject illegal drugs.

WHAT ARE THE TESTS FOR TB INFECTION?

THE TB SKIN TEST

The TB skin test may be used to find out if you are infected with TB bacteria. You can get a skin
test at the health department or at your doctor’s office. A health care worker will inject a small amount of testing fluid (called tuberculin or PPD) into the skin on the lower part of your arm. After 2 or 3 days, you must return to have your skin test read by the health care worker. You may have swelling where the tuberculin was injected. The health care worker will measure this swelling and tell you if your reaction to the test is positive or negative. A positive reaction usually means that you have been infected by someone with TB disease.
If you have recently been infected with TB bacteria, your TB skin test reaction may not be positive yet. You may need a second skin test 8 to 10 weeks after the last time you spent time with the person with TB disease. This is because it can take several weeks after infection for your immune system to react to the TB skin test. If your reaction to the second test is negative, you probably do not have TB infection.

TB BLOOD TESTS

TB blood tests use a blood sample to find out if you are infected with TB bacteria. The tests measure the response of TB proteins when they are mixed with a small amount of blood. If your health department does offer the TB blood tests, only one visit is required to draw blood for the test. Examples of these TB blood tests include QuantiFERON®-TB Gold in-Tube test (QFT-GIT) and T-Spot® .TB test.

WHAT IF I HAVE A POSITIVE TEST FOR TB INFECTION?

If you have a positive reaction to the TB skin test or TB blood test, your doctor or nurse may do other tests to see if you have TB disease. These tests usually include a chest x-ray. They may also include a test of the sputum you cough up. Because the TB bacteria may be found somewhere other than your lungs, your doctor or nurse may check your urine, take tissue samples, or do other tests. If you have TB disease, you will need to take medicine to treat the disease.

WHAT IF I HAVE BEEN VACCINATED WITH BCG?

BCG is a vaccine for TB. This vaccine is not widely used in the United States, but it is often given to infants and small children in other countries where TB is common. BCG vaccine does not always protect people from getting TB.
If you were vaccinated with BCG, you may have a positive reaction to a TB skin test. This reaction may be due to infection with the TB bacteria. However, in some people, BCG may cause a positive skin test when they are not infected with TB bacteria.
A positive reaction is more likely to mean you have been infected with TB bacteria if:
• You recently spent time with a person who has TB disease; or
• You are from an area of the world where TB disease is very common (such as most countries in Latin America and the Caribbean, Africa, Asia, Eastern Europe, and Russia); or
• You spend time where TB disease is common (homeless shelters, migrant farm camps, drug-treatment centers, health care clinics, jails, prisons).
Unlike the TB skin test, TB blood tests are not affected by prior BCG vaccination. The TB blood tests are less likely to give a false-positive result in people who have received BCG.

IF I HAVE LATENT TB INFECTION, HOW CAN I KEEP FROM DEVELOPING TB DISEASE?

Many people who have latent TB infection never develop TB disease. But some people who have latent TB infection are more likely to develop TB disease than others. Those at high risk for TB disease 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 TB blood test) and you are in one of these high-risk groups, you need to take medicine to keep from developing TB disease. This is called treatment for latent TB infection. There are several treatment options.
One treatment option for latent TB infection is isoniazid (INH). Taken for 6 to 9 months, INH kills the TB bacteria that are in the body. If you take your medicine as instructed by your doctor or nurse, it can keep you from developing TB disease. Children, adolescents, and people infected with HIV who have latent TB infection need to take INH for 9 months. The preferred regimen for children 2-11 years old is 9 months of daily INH.
Another effective treatment option for people with latent TB infection is the 12-dose regimen. This regimen of INH and rifapentine (RPT) is taken once a week for 3 months under directly observed therapy (DOT). This means the patient will meet with a health worker at a place they both agree on, and the health worker will observe the patient taking the medicine.
You and your health care provider must decide which treatment option is best for you.
Because there are less bacteria, treatment for latent TB infection is much easier than treatment for TB disease. A person with TB disease has a large amount of TB bacteria in the body. Several drugs are needed to treat TB disease.
Sometimes people are given treatment for latent TB infection even if their TB skin test reaction or TB blood test result is negative. This is often done with infants, children, and people infected with HIV who have recently spent time with someone with TB disease. This is because they are at very high risk of developing TB disease soon after they become infected with TB bacteria.
If you start taking treatment for latent TB infection, you will need to see your doctor or nurse on a regular schedule. It is important that you take all the pills as prescribed. The doctor or nurse will check on how you are doing. Some people have serious side effects from these medicines. If you have any of the following side effects, call your doctor or nurse right away:
• No appetite
• Nausea
• Vomiting
• Yellowish skin or eyes
• Fever for 3 or more days
• Abdominal pain
• Tingling in the fingers and toes
• Pain in lower chest or heartburn
• Feeling itchy
• Skin rash
• Easy bruising
• Bleeding from gums
• Nose bleeding
• Urine becomes dark or brown in color
• Aching joints
• Dizziness
Warning: Frequent or heavy drinking of alcoholic beverages (wine, beer, and liquor) while taking treatment for latent TB infection can be dangerous. Check with your doctor or nurse for more information..
People who have latent TB infection need to know the symptoms of TB disease. If they develop symptoms of TB disease, they should see a doctor right away.

WHAT IF I HAVE HIV INFECTION?

Because HIV infection weakens the immune system, people with latent TB infection and HIV infection are at very high risk of developing 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 TB disease. If they have TB disease, they must take medicine to treat the disease.
TB disease can be prevented and treated, even in people with HIV infection.

IF I WAS EXPOSED TO SOMEONE WITH TB DISEASE, CAN I GIVE TB TO OTHERS?

If you were exposed to someone with TB disease, you may become infected with TB bacteria, but you would not be able to spread the bacteria to others right away. Only persons with TB disease can spread TB to others. Before you would be able to spread TB bacteria to others, you would have to breathe in TB bacteria and become infected. Then the bacteria would have to multiply in your body and cause TB disease. At this point, you could possibly spread TB bacteria to others.
Some people develop TB disease soon (within weeks) after becoming infected, before their immune system can fight the TB bacteria. Other people may get sick years later, when their immune system becomes weak for another reason. Many people with TB infection never develop TB 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 cannot spread TB bacteria to others. People who have latent TB infection can be treated to prevent developing TB disease.

HOW IS TB DISEASE TREATED?

There is good news for people with TB disease! It can almost always be treated
 and cured with medicine. But the medicine must be taken as directed by your doctor or nurse.
If you have TB disease, you will need to take several different medicines. This is because there are many bacteria to be killed. Taking several medicines will do a better job of killing all of the bacteria and preventing them from becomingresistant to the medicines.
The most common medicines used to treat TB disease are:
• isoniazid (INH)
• rifampin (RIF)
• ethambutol
• pyrazinamide

If you have TB disease of the lungs or throat, you are probably infectious. You need to stay home from work or school so that you don’t spread TB bacteria to other people. After taking your medicine for a few weeks, you will feel better and you may no longer be infectious to others. Your doctor or nurse will tell you when you can return to work or school or visit with friends.

Having TB disease should not stop you from leading a normal life. When you are no longer infectious or feeling sick, you can do the same things you did before you had TB disease. The medicines that you are taking should not affect your strength, sexual function, or ability to work. If you take your medicines as directed by your doctor or nurse, they should kill all the TB bacteria. This will keep you from becoming sick again.

WHAT ARE THE SIDE EFFECTS OF TB DISEASE MEDICINES?

If you are taking medicines for TB disease, you should take it as directed by your
doctor or nurse. The medicines may cause side effects. Some side effects are minor problems. Others are more serious. If you have a serious side effect, call your doctor or nurse immediately. You may be told to stop taking your medicine or to return to the clinic for tests.
The side effects listed below are serious. If you have any of these symptoms, call your doctor or nurse immediately:

• No appetite
• Nausea
• Vomiting
• Yellowish skin or eyes
• Fever for 3 or more days
• Abdominal pain
• Tingling in the fingers or toes
• Pain in the lower chest or heart burn
• Feeling itchy
• Skin rash
• Easy bruising
• Bleeding from gums
• Nose bleeding
• Urine becomes dark or brown in color
• Aching joints
• Dizziness
• Tingling or numbness around the mouth
• Blurred or changed vision
• Ringing in the ears
• Hearing loss

The side effects listed below are minor problems. If you have any of these side effects, you can continue taking your medicine.

• Rifampin can turn urine, saliva, or tears orange. The doctor or nurse may advise you not to wear soft contact lenses because they may get stained.
• Rifampin can make you more sensitive to the sun. This means you should use a good sunscreen and cover exposed areas so you don’t burn.
• Rifampin makes birth control pills and implants less effective. Women who take rifampin should use another form of birth control.
• If you are taking rifampin as well as methadone (used to treat drug addiction), you may have withdrawal symptoms. Your doctor or nurse may need to adjust your methadone dosage.

WHY DO I NEED TO TAKE TB MEDICINES REGULARLY?

TB bacteria die very slowly. It takes at least 6 months for the medicines to kill all the TB bacteria. You will probably start feeling well after only a few weeks of treatment. But beware! The TB bacteria are still alive in your body. You must continue to take your medicines until all the TB bacteria are dead, even though you may feel better and have no more symptoms of TB disease.
If you don’t continue taking your medicines or you aren’t taking all your medicines regularly, this can be very dangerous. The TB bacteria will grow and you will remain sick for a longer time. The bacteria may also become resistant to the medicines you are taking. You may need new, different medicines to kill the TB bacteria if the old medicines no longer work. These new medicines must be taken for a longer time and usually have more serious side effects.
If you become infectious again, you could give TB bacteria to your family, friends, or anyone else who spends time with you. It is very important to take your medicines as directed by your doctor or nurse.

WHAT IS DIRECTLY OBSERVED THERAPY (DOT)?

The best way to remember to take your medicines 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 medicines 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 medicines and complete your treatment. This means you will get well as soon as possible. With DOT, you may need to take medicines only 2 or 3 times each week instead of every day.
The health care worker will make sure that the medicines are working as they 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 medicines. This will continue until you are cured.

HOW CAN I REMEMBER TO TAKE MY MEDICINES IF I AM NOT ON DOT?

The only way to get well is to take your medicines exactly as directed by your doctor or nurse. This may not be easy! You will be taking your medicines for a long time (6 months or longer), so you should get into a routine. Here are some ways to help you remember to take your medicines:
• Take your pills at the same time every day — for example, you can take them before eating breakfast, during a regular coffee break, or after brushing your teeth.
• Ask a family member or a friend to remind you to take your pills.
• Mark off each day on a calendar as you take your medicine.
• Put your pills in a weekly pill dispenser. Keep it by your bed or in your purse or pocket.
NOTE: Remember to keep all medicine out of reach of children.
If you forget to take your pills one day, skip that dose and take the next scheduled dose. Tell your doctor or nurse that you missed a dose. You may also call your doctor or nurse for instructions.

HOW CAN I KEEP FROM SPREADING TB?

The most important way to keep from spreading TB is to take all your medicines, exactly as directed by your doctor or nurse. You also need to keep all of your clinic appointments! Your doctor or nurse needs to see how you are doing. You may need another chest x-ray or a test of the phlegm you may cough up. These tests will show whether the medicines are working. They will also show whether you can still give TB bacteria to others. Be sure to tell the doctor about anything you think is wrong.
If you are sick enough with TB disease to go to a hospital, you may be put in a special room. These rooms use air vents that keep TB bacteria from spreading to other rooms. People who work in these special rooms must wear a special face mask to protect themselves from TB bacteria. You must stay in the room so that you will not spread TB bacteria to other people. Ask a nurse for anything you need that is not in your room.

If you are infectious while you are at home, there are things you can do to protect others near you.
• Take your medicines as directed. This is very important!
• Always cover your mouth with a tissue when you cough, sneeze, or laugh. Put the tissue in a closed bag and throw it       away.
• Do not go to work or school. Separate yourself from others and avoid close contact with anyone. Sleep in a bedroom       away from other family members.
• Air out your room often to the outside of the building (if it is not too cold outside). TB spreads in small closed spaces     where air doesn’t move. Put a fan in your window to blow out (exhaust) air that may be filled with TB bacteria. If you       open other windows in the room, the fan also will pull in fresh air. This will reduce the chances that TB bacteria will stay     in the room and infect someone who breathes the air.

Remember, TB is spread through the air. People cannot get infected with TB bacteria through handshakes, sitting on toilet seats, or sharing dishes and utensils with someone who has TB.
After you take the medicines for about 2 or 3 weeks, you may no longer be able to spread TB bacteria to others. If your doctor or nurse agrees, you will be able to go back to your daily routine, including returning to work or school. Remember, you will get well only if you take your medicines exactly as directed by your doctor or nurse.
Think about people who may have spent time with you, such as family members, close friends, and coworkers. The local health department may need to test them for TB infection. TB is especially dangerous for children and people infected with HIV. If infected with TB bacteria, these people need medicine right away to keep from developing TB disease.

WHAT ARE MULTIDRUG-RESISTANT TB (MDR TB) AND EXTENSIVELY DRUG-RESISTANT TB (XDR TB)?

Sometimes the TB bacteria are resistant to the medicines used to treat TB disease. This means that the medicine can no longer kill the bacteria. Multidrug-resistant TB, or MDR TB is caused by bacteria that are resistant to two or more of the most important TB medicines: INH and RIF.
A more serious form of MDR TB is called extensively drug-resistant TB (XDR TB). XDR TB is a rare type of TB that is resistant to nearly all medicines used to treat TB disease.
If you do not take your medicines as directed by your doctor or nurse, the TB bacteria may become resistant to a certain medicine. Also, people who have spent time with someone sick with MDR TB or XDR TB disease can become infected with these multidrug-resistant bacteria.
Drug resistance is more common in people who:
• Have spent time with someone with drug-resistant TB disease;
• Do not take all of their medicines as directed by their doctor or nurse;
• Develop TB disease again, after having taken TB medicines in the past; or
• Come from areas where drug-resistant TB is common.
People with MDR TB or XDR TB disease must be treated with special medicines. These medicines are not as good as the usual medicines for TB, and they may cause more side effects. Also, people with MDR TB and XDR TB disease must see a TB expert who can closely observe their treatment to make sure it is working. Treatment takes much longer than regular TB. And, people with both MDR TB and XDR TB are at greater risk of dying from the disease.

References:

http://www.cdc.gov/tb/publications/faqs/default.htm