Tuberculosis

Fitango Education
Health Topics

Tuberculosis

http://www.fitango.com/categories.php?id=154

Overview
In developed countries, such as the United
States, many people think TB is a disease of the
past. TB, however, is still a
leading killer of young adults worldwide. Some 2
billion people—one-third of

http://www.fitango.com/categories.php?id=154 1

Overview
the world's population—are thought to be infected
with TB bacteria, Mycobacterium
tuberculosis (Mtb).
TB is a chronic bacterial infection. It is
spread through the air and usually infects the
lungs, although other organs and


Overview
parts of the body can be involved as well. Most
people who are infected with Mtbharbor
the bacterium without symptoms (have latent TB),
but some will develop active
TB disease. In 2010, an estimated 8.8 million
people fell ill with TB, including


Overview
1.1 million cases among people with HIV, according
to the World Health
Organization.
One in 10 people who are infected with Mtb may
develop active TB at some time in their lives. The
risk of developing active


Overview
disease is greatest in the first year after infection,
but active disease often
does not occur until many years later.


Causes
**Bacterium**
Tuberculosis is caused by the infectious
agent known as Mycobacterium
tuberculosis (Mtb). This rod-shaped
bacterium, also called Koch's bacillus, was
discovered by Dr. Robert Koch in


Causes
**Bacterium**
1882.
**Characteristics**
-- Mtb is a small, slow-growing bacterium
that can live only in people. It is not found in other
animals, insects, soil,
or other nonliving things.


Causes
**Bacterium**
-- Mtb is an aerobic bacterium, meaning
it needs oxygen to survive. For this reason, during
active TB disease, Mtb complexes
are always found in the upper air sacs of the lungs.


Causes
**TB Infection**
When a person breathes in Mtb-contaminated
air, the inhaled TB bacteria reach the lungs. This
causes an Mtb infection.
However, not everyone infected with TB bacteria
becomes sick. The bacteria can


Causes
**TB Infection**
remain dormant (asleep) for years and not cause
any TB disease. This is called
latent TB infection. People who have latent TB
infection do not get sick and do
not spread the bacteria to others. But, some
people with latent TB infection
eventually do get TB disease.


Causes
**TB Infection**
So it is important to get the appropriate
treatment and get rid of the bacteria even in latent
TB infection.


Causes
**TB Disease**
For someone to develop active TB disease,
the following two events must take place:
-- The bacteria enter the body and cause
an Mtb infection.
-- The immune system cannot stop the TB


Causes
**TB Disease**
bacteria from growing and spreading after the
initial infection.
The active bacteria multiply and destroy
the tissue. A person with TB disease shows
symptoms that vary, depending on
where the TB bacteria are growing. In most cases,
the bacteria attack the


Causes
**TB Disease**
lungs.
http://www.niaid.nih.gov/topics/tuberculosis/Und
erstanding/Pages/cause.aspx


Transmission
TB is primarily an airborne disease. The
bacteria are spread from person to person in tiny
microscopic droplets when a
TB sufferer coughs, sneezes, speaks, sings, or
laughs. Only people with active


Transmission
TB can spread the disease to others.


Symptoms
Early symptoms of active TB can include
weight loss, fever, night sweats, and loss of
appetite. Symptoms may be vague,
however, and go unnoticed by the affected person.
For some, the disease either


Symptoms
goes into remission (halts) or becomes chronic and
more debilitating with
cough, chest pain, and bloody sputum (saliva).
Symptoms of TB involving areas other than
the lungs vary, depending upon the organ or area
affected.


Diagnosis
To identify those who may have been exposed
to Mycobacterium tuberculosis (Mtb), healthcare
providers typically
inject a substance called tuberculin under the skin
of the forearm. If a red


Diagnosis
welt forms around the injection site within 72
hours, the person may have been
infected. This doesn't necessarily mean he or she
has active disease. People
who may test positive on the tuberculin test
include:
-- Most people with previous exposure to Mtb


Diagnosis
-- Some people exposed to bacteria related to Mtb
-- Some people born outside the United States
who were vaccinated with the TB vaccine used in
other countries
If people have an obvious reaction to the


Diagnosis
skin test, other tests can help to show if they have
active TB. In making a
diagnosis, healthcare providers rely on symptoms
and other physical signs, the
person's history of exposure to TB, and X-rays that
may show evidence of Mtb infection.


Diagnosis
The healthcare provider also will take
sputum and other samples to see if the TB bacteria
will grow in the laboratory.
If bacteria are growing, this positive culture
confirms the diagnosis of TB.
BecauseMtb grows very slowly, it can take 4 weeks
to confirm the


Diagnosis
diagnosis. An additional 2 to 3 weeks usually are
needed to determine which
antibiotics to use to treat the disease.


Diagnosis
**What Happens When Someone Gets Infected
with Mtb?**
Between 2 to 8 weeks after being infected
with Mtb a person's immune system responds to
the TB germ by walling


Diagnosis
off infected cells. From then on the body maintains
a standoff with the
infection, sometimes for years. Most people
undergo complete healing of their
initial infection, and the bacteria eventually die off.
A positive TB skin


Diagnosis
test, and old scars on a chest X-ray, may provide
the only evidence of the
infection.
If, however, the body's resistance is low
because of aging, infections such as HIV,
malnutrition, or other reasons, the


Diagnosis
bacteria may break out of hiding and cause active
TB.
http://www.niaid.nih.gov/topics/tuberculosis/und
erstanding/pages/diagnosis.aspx


Treatment
With appropriate antibiotic treatment, TB
can be cured in most people. Successful treatment
of TB depends on close
cooperation between patients and healthcare
providers. Treatment usually


Treatment
involves taking several antibiotic drugs for at least
6 months and sometimes
for as long as 12 months.


Treatment
**Antibiotic Resistance and the Importance of
Finishing the TB Medicine**
People who do not take all the required
medicines can become sick again and spread TB to
others. Additionally, when


Treatment
people do not take all the prescribed medicines or
skip times when they are
supposed to take them, the TB bacteria evolve to
outwit the TB antibiotics.
Soon those medicines no longer work against the
disease. If this happens, the


Treatment
person now has drug-resistant TB. Additionally,
some people with TB do not get
better with treatment because their disease is
caused by a strain of the TB
bacterium that is already resistant to one or more
of the standard TB drugs.
Multidrug-resistant TB (MDR TB) is TB that


Treatment
is resistant to at least two of the best Food and
Drug Administration-approved
anti-TB drugs, isoniazid and rifampicin. These
antibiotics are considered
first-line drugs and are the first medicines used to
treat all persons with TB


Treatment
disease. Extensively drug-resistant TB (XDR TB) is a
relatively rare type of TB
that is resistant to isoniazid and rifampin, plus any
fluoroquinolone and at
least one of three injectable second-line drugs
(such as amikacin, kanamycin,


Treatment
or capreomycin). Worldwide, TB drug resistance is
on the rise. In 2010, the
World Health Organization estimated that more
than 650,000 people have MDR TB.


Treatment
**Treatment for Drug Resistant TB**
Treatment for drug-resistant TB often
requires the use of special TB drugs, all of which
can produce serious side
effects. People with MDR TB may have to take
several antibiotics, at least


Treatment
three to which the bacteria still respond, every day
for up to two years.
Even with this treatment, however, between 4 and
6 out of 10 patients
with MDR TB will die, which is the same rate seen
with TB patients who are not


Treatment
treated. Because XDR TB is resistant to first-line
and second-line drugs,
patients are left with limited treatment options
that are much less effective.
For more information on drug-resistant
tuberculosis, please see the Drug-Resistant


Treatment
TB Visual Tour.
**Infection Control**
Hospitals and clinics take precautions to
prevent the spread of TB, which include identifying
patients with suspected TB


Treatment
and using ultraviolet light to sterilize the air, special
filters, and special
respirators and masks. In hospitals, people with TB
are isolated in special
rooms with controlled ventilation and airflow until
they can no longer spread


Treatment
TB bacteria. By having an infection control plan in
place, healthcare settings
can ensure the prompt detection and treatment of
persons who have suspected or
confirmed TB disease.


Prevention
TB is an airborne disease and transmission
essentially can be prevented through adequate
ventilation and limited contact
with patients.
Many people who are infected
with Mycobacterium


Prevention
tuberculosis (Mtb) do not get sick or spread the
bacteria to others — this
is known as latent TB. In the United States and
many other countries,
healthcare providers try to identify people infected
with Mtb as


Prevention
early as possible, before they advance from latent
to active TB.
Some people at higher risk for developing
active TB are:
-- People with HIV infection
-- People who became infected with TB bacteria


Prevention
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


Prevention
-- Elderly people
-- People who were not treated correctly for
TB in the past
People in high risk groups can be treated
with medicine to prevent active TB disease and
should meet with their


Prevention
healthcare providers to determine the appropriate
treatment.
**TB Vaccine**
In those parts of the world where the
disease is common, the World Health Organization
recommends that infants


Prevention
receive a vaccine called BCG (Bacille Calmette-
Guérin). BCG is fairly effective
in protecting small children from severe TB
complications. It does not protect
adults very well against lung TB, which is the form
of TB that is easiest to


Prevention
spread to others. BCG is not currently
recommended for infants in the United
States.
http://www.niaid.nih.gov/topics/tuberculosis/und
erstanding/Pages/prevention.aspx


Tuberculosis

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Tuberculosis

Similar to Tuberculosis (20)

More from fitango

More from fitango (20)

Tuberculosis