Tuberculosis etc. (American Lung Association, 2017) as shown

– also known as “TB” –  is a communicable
disease that most commonly affects the lungs of the body (Figure 1). This infectious
disease is also known to damage other organs of the body like the brain, kidneys,
or spine. Many people wonder what causes
Tuberculosis and how it can be contracted. Tuberculosis is caused by the
bacteria ‘Mycobacterium tuberculosis’, which permeates
through the air when someone with tuberculosis in their lungs coughs, spits,
laughs, sneezes,
talks, etc. (American Lung Association, 2017)
shown in figure 2. Since Tuberculosis is a contagious and slow developing
pathogen, it can be contracted from spending copious amounts of time with an individual
who has the infection, like a family member or coworker; however, one can still
contract it from a stranger (American Lung Association, 2017). Tuberculosis is
one of the oldest illnesses in the world known to humans and is still one of
the most common reasons for death today (Smith, 2003).

Now, as previously mentioned, the
bacterium Mycobacterium tuberculosis, the cause of TB, is a pathogenic
bacterium that was first discovered in 1882 by Robert Koch (Microbiology in Pictures, 2016). This organism has an
uncommon, waxy layer on the cell surface which is mainly comprised of mycolic
acid. This coating is what makes the cells resistant to Gram staining, so
instead, acid-fast techniques are utilized (Microbiology In Pictures, 2016). Additionally,
the bacteria requires a high concentration of oxygen to grow, and divides every
15-20 hours, which is extremely slow in comparison to other bacteria, which
usually divide in minutes (Microbiology in Pictures, 2016). It also has cell
walls that are rich in lipids and this aspect is most likely responsible for
the bacteria’s virulence and resistance (Microbiology in
Pictures, 2016). When in the lungs, Mycobacterium tuberculosis is taken up
by alveolar macrophages, but they are unable to digest the bacterium resulting
from the cell wall, preventing the fusion of the phagosome with a lysosome (Smith,
2003). This induces the bacterium to multiply unchecked within the macrophage, thus
allowing the organism to grow. The pathogen can also survive for weeks in dust,
on carpet, or clothes, as well as for months in sputum (Center for Disease
Control and Prevention, 2016).

is commonly found in two forms: Latent and Active TB.  Persons with latent TB are infected with Mycobacterium tuberculosis, but do not have the
tuberculosis disease (Mayo Clinic, 2017). Due to
the disease’s dormancy within patients, they often display no signs or symptoms
of the disease (Mayo Clinic, 2017). Therefore, they are not infectious, and cannot
spread TB to others. However, active TB is when the bacterium successfully
infects the patient, thus succumbing him/her to the disease (Mayo Clinic, 2017).
This person is highly contagious and can transmit the disease to others. Ninety
percent of adult cases of active TB are from the reactivation of a latent TB
infection (AAFP, 2017).

Additionally, those who contract tuberculosis
demonstrate a variety of symptoms. Although latent TB is mostly symptomless, common
indicators of active TB include coughing with mucous or blood, chest pain,
unintentional weight loss, fever, fatigue, night sweats and chills (Mayo
Clinic, 2017). Tuberculosis can also spread via the bloodstream to affect other
vital components of the body if treatment is not provided. For instance, it can
lead to spinal pain and stiffness if it reaches the spine, it can lead destruction
of joints if it reaches bones, and as it infects the brain it can lead to meningitis
which can cause headaches and mental changes (Mayo Clinic, 2017). This can also
negatively affect the liver and kidneys as it damages their waste filtration
functions, and even though it is rare for TB to infect the heart, it can impair
the heart’s capabilities to pump blood effectively which is fatal (Mayo Clinic, 2017).

Furthermore, those who have a weak immune
system have a higher probability to acquire tuberculosis such as, infants and
children whose immune system have not fully matured, people who were infected previously,
persons infected with HIV, and those who have certain conditions like diabetes
or chronic renal failure (American Lung Association, 2017). Nonetheless, other external elements can higher the
chance of also obtaining the disease.  For
instance, tobacco and alcohol use has been found to increase the risk of
developing active tuberculosis (McIntosh, 2017). In the 20th century TB was the
leading cause of death in the U.S., and today is regarded as one of the major
causes of disability and death worldwide (Center for Disease Control and
Prevention, 2016). In 2015, 10.4 million people fell ill with TB, and 1.8
million died from the disease, as shown in Figure 3 (World Health Organization,
2017). According to the World Health Organization, more than 95 percent of
those TB deaths occurred in low and middle-income countries like Mexico, Africa,
or Eastern Europe as shown in Figure 4 (World Health Organization, 2017). In
fact, one third of the global population has latent TB infection, and five to
ten percent of those infected people will eventually develop the active TB
disease (McIntosh, 2017).

            Moreover, a multitude of
tuberculosis cases can be cured with sufficiently administering medication and
treatment. There are many factors that contribute to the alleviation of tuberculosis
within patients, such as, age, health, possible resistance to drugs, whether it
is latent or active TB, and the location of the infection within the body (McIntosh,
2017).  People with latent TB usually require
lesser doses of one or more TB prescriptions, in contrast to those with active
TB who will require higher doses, and an assortment of antibiotics and other
medications (Mayo Clinic, 2017). The standard length of time for a course of TB
antibiotics is about 6 months (Center for Disease Control, 2016). Luckily,
there are tests that can be taken to diagnose for TB. The skin test (purified
protein derivative aka PPD), is when an extract of the TB bacterium is
administered under the skin of the inner forearm via intramuscular injection and
is the most common test administered for diagnosing TB (Punnoose, 2013). In
response to this injection, if a person has been infected with TB, immune cells
will harden the area surrounding the injection site. The area of hardening is monitored
for 48 to 72 hours after injection and used to determine whether a TB infection
is within one’s body. (Punnoose, 2013). Unfortunately, however, the skin test
is not 100 percent accurate and has been known to incorrectly indicate the
presence of the infectious disease (McIntosh, 2017). Nevertheless, other tests are
available like chest x-rays, which may be done to distinguish between active
and latent TB, or blood tests, which may be done to check for cytokines that
are unique to TB infections (McIntosh, 2017). These may be used alongside the
skin test to diagnose tuberculosis.