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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 spread throughout 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. This is referred to
as latent TB.
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. This is
referred to as active TB.
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. Most active cases of TB disease result
from activating old infection in people with
impaired immune systems.
Someone in
the world is newly infected with TB bacilli
every second and one-third of the world’s
population is currently infected with
TB. 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 has been
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 strengthened further. Each
year there are more than 8.8 million cases and
close to 1.6 million deaths attributed to
TB.
WHO
GETS IT?
Anyone can get TB. However,
some groups 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
-
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
malnourished
-
Alcoholics, IV drug
users and people who are
homeless
WHAT ARE THE SYMPTOMS OF
TB?
A person with TB infection will
have no symptoms. A person with active TB
disease may have any, all or none of the
following symptoms:
-
A persistent
cough
-
Constant
fatigue
-
Weight
loss
-
Loss of
appetite
-
Fever
-
Coughing up
blood
-
Night
sweats
These symptoms can also occur with
other diseases 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 may be due to a variety of reasons such
as another disease like AIDS or diabetes, drug
or alcohol abuse, lack of access to health care
and homelessness.
Whatever the
cause may be, when the body's ability to protect
itself is compromised, TB infection can become
active 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. The significance of the size
of the bump is determined in conjunction with
risk factors for TB.
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 or your jobs request
it.
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 active 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).
If you fall into
one or more of the high-risk categories for TB
noted earlier- for example, if you are
HIV-positive, never had a skin test before, or
there is no record of the last result- you
should be tested.
Some doctors and
clinics may now use newly developed blood tests
instead of the PPD skin test. 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 active TB
disease or only TB infection.
A person who
has become infected with TB, but does not have
active TB disease, may be given preventive
therapy. Preventive therapy aims to kill germs
that are not doing any damage right now, but
could so do.
If a doctor
decides a person should receive preventive
therapy, the usual prescription is a daily dose
of isoniazid (also called "INH"); an inexpensive
TB medicine. The person takes INH for 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 active 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
including rifampin, pyrazinamide and
ethambutol). 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, 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.
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.
WHAT IS
ENTENSIVELY-DRUG RESISTANT TB?
Extensively-drug resistant
tuberculosis (XDR TB) is a strain of TB with
extensive resistance to second-line drugs. XDR
TB has emerged worldwide as a threat to public
health and TB control, raising concerns of a
future epidemic of virtually untreatable TB.
Presently, XDR TB is rare in the U.S. and
uncommon in the rest of the world. During
1993-2002, patients with XDR TB were 64% more
likely to die or have treatment
failure.
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 noninfectious; 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 noninfectious 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 infection.
Brief
exposure to a source of TB rarely infects a
person. It's day-after-day close contact that
usually does it.
TB: WHAT YOU SHOULD
DO
Find out if
you're infected.

Certain
people such as those infected with HIV or health
care workers should be tested regularly. You
should 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.
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