Tuberculosis (TB) describes
an infectious disease that has plagued humans since the Neolithic times.
Tuberculosis — or TB, as it’s commonly called — is a contagious infection
that usually attacks the lungs. It can also spread to other parts of the body,
like the brain and spine. Tuberculosis is an infectious disease that usually
affects the lungs. Compared with other diseases caused by a single infectious
agent, tuberculosis is the second biggest killer, globally.
During the 17th and 18th
centuries, TB caused up to 25% of all deaths in Europe. In the 20th century, TB
was a leading cause of death in the United States.
There are two forms of the
Latent TB: The bacteria remain
in the body in an inactive state. They cause no symptoms and are not
contagious, but they can become active. That means you don’t have any symptoms
and you’re not contagious. But the infection is still alive in your body and
can one day become active. You are at high risk for re-activation — for
instance, you have HIV, your primary infection was in the last 2 years, your
chest X-ray is abnormal, or you are immunocompromised
Active TB disease: The
bacteria do cause symptoms and can be transmitted to others. Ninety percent of
adult cases of active TB are from the reactivation of a latent TB infection.
About one-third of the world’s population is believed to have latent TB. People
infected with TB bacteria have a 5–15% lifetime risk of falling ill with TB. However,
persons with compromised immune systems, such as people living with HIV,
malnutrition or diabetes, or people who use tobacco, have a much higher risk of
Two organisms cause
tuberculosis — Mycobacterium tuberculosis and Mycobacterium bovis.
Common symptoms of active
lung TB are cough with sputum and blood at times, chest pains, weakness, weight
loss, fever and night sweats.
How does it spread?
TB is spread from person to
person through the air. When people with lung TB cough, sneeze or spit, they
propel the TB germs into the air.
TB (MDR-TB), Extensively drug-resistant TB (XDR-TB)
Anti-TB medicines have been
used for decades and strains that are resistant to 1 or more of the medicines
have been documented in every country surveyed. Drug resistance emerges when
anti-TB medicines are used inappropriately, through incorrect prescription by
health care providers, poor quality drugs, and patients stopping treatment
tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to
isoniazid and rifampicin, the 2 most powerful, first-line anti-TB drugs. MDR-TB
is treatable and curable by using second-line drugs. However, second-line
treatment options are limited and require extensive chemotherapy (up to 2 years
of treatment) with medicines that are expensive and toxic.
In some cases, more severe
drug resistance can develop. Extensively drug-resistant TB (XDR-TB) is a more
serious form of MDR-TB caused by bacteria that do not respond to the most
effective second-line anti-TB drugs, often leaving patients without any further
Worldwide, only 54% of
MDR-TB patients and 30% of XDR-TB are currently successfully treated. In 2016,
WHO approved the use of a short, standardised regimen for MDR-TB patients who
do not have strains that are resistant to second-line TB medicines. . Patients
with XDR-TB or resistance to second-line anti-TB drugs cannot use this regimen,
however, and need to be put on longer MDR-TB regimens to which 1 of the new
drugs (bedaquiline and delamanid) may be added.
Tuberculosis is diagnosed by detecting Mycobacterium tuberculosis
bacteria in clinical specimen which is taken from the infectant. There are
different types of diagnosis process for TB.