WHAT IS TB?
Tuberculosis (often called TB) is an infectious disease that usually attacks the
lungs, but can attack almost any part of the body. Tuberculosis is spread from
person to person through the air.
When people with TB in their lungs or throat cough, laugh, sneeze, sing, or even
talk, the germs that cause TB may be spread into the air. If another person
breathes in these germs there is a chance that they will become infected with
tuberculosis. Repeated contact is usually required for infection.
It is important to understand that there is a difference between being infected
with TB and having TB disease. Someone who is infected with TB has the TB germs,
or bacteria, in their body. The body's defenses are protecting them from the
germs and they are not sick.
Someone with TB disease is sick and can spread the disease to other people. A
person with TB disease needs to see a doctor as soon as possible.
It is not easy to become infected with tuberculosis. Usually a person has to be
close to someone with TB disease for a long period of time. TB is usually spread
between family members, close friends, and people who work or live together. TB
is spread most easily in closed spaces over a long period of time. However,
transmission in an airplane, although rare, has been documented.
Even if someone becomes infected with tuberculosis, that does not mean they will
get TB disease. Most people who become infected do not develop TB disease
because their body's defenses protect them.
Experts believe that about 10 million Americans are infected with TB germs. Only
about 10 percent of these people will develop TB disease in their lifetime. The
other 90 percent will never get sick from the TB germs or be able to spread them
to other people.
TB is an increasing and major world wide problem, especially in Africa where the
spread is facilitated by AIDS. It is estimated that nearly 1 billion people will
become newly infected, over 150 million will become sick, and 36 million will
die worldwide between now and 2020 if control is not further strengthened. Each
year there are more than 8.7 million cases and close to 2 million deaths
attributed to TB; 100,000 of those 2 million deaths occur among children.
WHO
GETS IT?
Anyone can get TB. People of all races and nationalities. The rich and poor. And
at any age. But for many reasons, some groups of people are at higher risk to
get active TB disease. The groups that are at high risk include:
- People with HIV infection
(the AIDS virus)
- People in close contact with
those known to be infectious with TB
- People with medical
conditions that make the body less able to protect itself from disease (for
example: diabetes, the dust disease silicosis, or people undergoing treatment
with drugs that can suppress the immune system, such as long-term use of
corticosteroids)
- Foreign-born people from
countries with high TB rates
- Some racial or ethnic
minorities
- People who work in or are
residents of long-term care facilities (nursing homes, prisons, some hospitals)
- Health care workers and
others such as prison guards
- People who are mal-nourished
- Alcoholics and IV drug users
WHAT ARE THE SYMPTOMS OF TB?
A person with TB infection will have no symptoms. A person with TB disease may
have any, all or none of the following symptoms:
- A cough that will not go away
- Feeling tired all the time
- Weight loss
- Loss of appetite
- Fever
- Coughing up blood
- Night sweats
These symptoms can also occur
with other types of lung disease so it is important to see a doctor and to let
the doctor determine if you have TB.
It is also important to remember that a person with TB disease may feel
perfectly healthy or may only have a cough from time to time. If you think you
have been exposed to TB, get a TB skin test.
HOW
DOES TB DISEASE DEVELOP?
- There are two possible ways a
person can become sick with TB disease:
- The first applies to a person
who may have been infected with TB for years and has been perfectly healthy. The
time may come when this person suffers a change in health. The cause of this
change in health may be another disease like AIDS or diabetes. Or it may be drug
or alcohol abuse or a lack of health care because of homelessness.
- Whatever the cause, when the
body's ability to protect itself is damaged, the TB infection can become TB
disease. In this way, a person may become sick with TB disease months or even
years after they first breathed in the TB germs.
- The other way TB disease
develops happens much more quickly. Sometimes when a person first breathes in
the TB germs the body is unable to protect itself against the disease. The germs
then develop into active TB disease within weeks.
WHAT IS THE TB SKIN TEST?
The TB skin test is a way to find out if a person has TB infection. Although
there is more than one TB skin test, the preferred method of testing is to use
the Mantoux test.
For this test, a small amount of testing material is placed just below the top
layers of skin, usually on the arm. Two to three days later a health care worker
checks the arm to see if a bump has developed and measures the size of the bump.
If the bump is of a certain size (varying with group) the test is significant
and the person is presumed to have TB infection.
Once the doctor knows that a person has TB infection he or she will want to
determine if the person has TB disease. This is done by using several other
tests including a chest X-ray and a test of a person's mucus (the material that
is sometimes coughed up from the lungs).
Q: Should you get a skin test each year to check on TB?
A: Only if you are at high risk for getting or transmitting TB.
The advice for most people is to get a tuberculin test if you have symptoms or
if you are living in close contact or have otherwise been in close contact with
someone who recently came down with TB disease. (Some people get skin tests
because of their jobs, in a school or hospital, for example, to make sure they
have not contracted TB and will not infect others if they have TB.)
However, if you fall into one or more of the high-risk categories for TB noted
earlier, for example, if you are HIV-positive, or if you've never had a skin
test before, or if there is no record of the last result, you should be tested.
If you're not sure, ask your doctor. TB can be prevented, even if you are at
risk.
WHAT IS THE TREATMENT FOR TB?
Treatment for TB depends on whether a person has TB disease or only TB
infection.
A person who has become infected with TB, but does not have TB disease, may be
given preventive therapy. Preventive therapy aims to kill germs that are not
doing any damage right now, but could break out later.
If a doctor decides a person should have preventive therapy, the usual
prescription is a daily dose of isoniazid (also called "INH"), an inexpensive TB
medicine. The person takes INH for six to nine months (up to a year for some
patients), with periodic checkups to make sure the medicine is being taken as
prescribed.
What if the person has TB disease? Then treatment is needed.
Years ago a patient with TB disease was placed in a special hospital for months,
maybe even years, and would often have surgery. Today, TB can be treated with
very effective drugs.
Often the patient will only have to stay a short time in the hospital and can
then continue taking medication at home. Sometimes the patient will not have to
stay in the hospital at all. After a few weeks a person can probably even return
to normal activities and not have to worry about infecting others.
The patient usually gets a combination of several drugs (most frequently INH
plus two to three others), usually for nine months. The patient will probably
begin to feel better only a few weeks after starting to take the drugs.
It is very important, however, that the patient continue to take the medicine
correctly for the full length of treatment. If the medicine is taken incorrectly
or stopped the patient may become sick again and will be able to infect others
with TB. As a result many public health authorities recommend Directly Observed
Therapy (DOT), in which a health care worker insures that the patient takes
his/her medicine.
If the medicine is taken incorrectly and the patient becomes sick with TB a
second time, the TB may be harder to treat because it has become drug resistant.
This means that the TB germs in the body are unaffected by some drugs used to
treat TB.
Multi-drug resistant TB is very dangerous, so patients should be sure that they
take all of their medicine correctly.
Regular checkups are needed to see how treatment is progressing. Sometimes the
drugs used to treat TB can cause side effects. It is important both for people
undergoing preventive therapy and people being treated for TB disease to
immediately let a doctor know if they begin having any unusual symptoms.
CAN A TB PATIENT INFECT OTHERS?
Yes, if they have TB disease and it is not being treated. Once treatment begins,
a patient ordinarily quickly becomes non-infectious; that is, they cannot spread
the disease to others.
There is little danger from the TB patient who is being treated, is taking his
or her medication continuously, and is responding well. The drugs usually make
the patient non-infectious within weeks.
TB is spread by germs in the air, germs put there by coughing or sneezing.
Handling a patient's bed sheets, books, furniture or eating utensils does not
spread the infection.
Brief exposure to a source of TB rarely infects a person. It's day-after-day
close contact that usually does it.
WHAT IS MULTI-DRUG RESISTANT TB?
Multi-drug resistant tuberculosis (called MDR TB for short) is a very dangerous
form of tuberculosis. Some TB germs become resistant to the effects of some TB
drugs. This happens when TB disease is not properly treated.
These resistant germs can then cause TB disease. The TB disease they cause is
much harder to treat because the drugs do not kill the germs. MDR TB can be
spread to others, just like regular TB.
It is important that patients with TB disease follow their doctor's instructions
for taking their TB medicine so that they will not develop MDR TB.
TB:
WHAT YOU SHOULD DO
Find out if you're infected.
Certain people such as those infected with HIV of health care workers should be
tested regularly. You should also be tested if there's any chance you have been
infected, recently or many years ago.
If the test is negative:
A negative reaction usually means that you are not infected and no treatment is
needed. However, if you have TB symptoms your doctor must continue to look for
the cause. Sometimes, when a person has only recently been infected, or when his
or her immune system isn't working properly, the test may be falsely negative.
If the test is positive:
A significant reaction usually means that you have been infected with the TB
germ. It does not necessarily mean that you have TB disease. Cooperate with the
doctor when he or she recommends a chest X ray and possibly other tests.
If the doctor recommends treatment to prevent sickness, follow the
recommendations. If medicine is prescribed, be sure to take it as directed.
If you don't need treatment, do what the doctor tells you to do about follow-up.The
doctor may simply say to return for another checkup if you get into a special
risk situation for TB sickness or develop symptoms.
If you are sick with TB disease, follow the doctor's recommendations for
treatment.
If you're a health worker:
Your local American Lung Association can provide you with more comprehensive
information developed for health professionals on the diagnosis, treatment and
control of TB. |
