The focus of this assignment will be both infectious and non-infectious diseases, along with a case
study of two specific diseases. The analysis includes assessing the physiological effects of the
diseases and the abnormalities they cause in one's structure or function. The term infectious disease in
medical terminology refers to a disease that can be transmitted from person to person and is caused by
bacteria, viruses, fungi or parasites. Examples of contagious disease are HIV or measles. These
microorganisms are called pathogens. On the other hand, an infected disease cannot be transmitted
from one individual to another. Genetics, diets, and environmental factors are some examples of
developing disease such as Cancer. Symptoms of infectious diseases do not appear immediately
following infecting an individual, but rather after the pathogen enters the organism (an animal, a
human, or a plant), it then reproduces rapidly under conditions conducive to increasing its number. A
disease's incubation period begins during this time. After the pathogen produces harmful toxins,
symptoms such as fevers and headaches occur.
Bacteria
Main features of bacteria: Bacteria are prokaryotic cells without true nucleus or organelles. They are
monocellular organisms. One of the three domains of life, bacteria are single celled organisms and are
referred to as bacteria with a capital B. They lack organelles like chloroplasts and mitochondria, and
unlike eukaryotic cells, they do not have a genuine nucleus. Instead, the nucleoid, an irregularly
shaped region without a nuclear membrane, contains the DNA of these cells, which is made up of a
double strand that is continuous and circular. Both the cell wall and the cell membrane of bacteria are
comprised of peptidoglycan, an amino acid and sugar compound. A bacteria cell can be recognised by
its regulated centre, which houses genetic data stored in a single DNA loop. The majority of bacteria
have a flagellum, which are tail-like cell structures that enable the bacteria to travel through liquids. In
addition, many bacteria have additional cell structures that aid in their survival. Additionally, they
contain a slime capsule that surrounds the cell wall to preserve the bacteria and prevent it from drying
up.
There are three basic shapes of bacteria. Round bacteria are known as cocci. A single, round bacteria
is referred to as a coccus. Furthermore, some other examples of bacteria are spherical bacteria which
can cause staph infections like boils, as well as cylindrical bacteria, such as bacilli that are physically
cylindrical in shape. A single cylindrical-shaped bacteria is known as a bacillus. Among the bacillus
bacteria is Escherichia coli (also referred to as E coli) can cause cholecystitis, urinary tract infections,
cholangitis, meningitis, and pneumonia. In addition, another type of bacteria is, Spirilla which refers
to spiral-shaped bacteria, while a spirillum is a single spiral-shaped bacterium. Helicobacter pylori, a
type of spirilla, damages stomach tissue and affects the stomach, causing pain and inflammation.
Peptic ulcers in the upper digestive system are brought on by these microorganisms.
, cocci bacilli spirilla
Bacterial disease Tuberculosis:
A bacterial disease called tuberculosis is caused by the bacteria Mycobacterium tuberculosis.
Mycobacterium tuberculosis, a bacillus, is most common in the lungs. As a tuberculosis affecting the
lungs, it is known as pulmonary tuberculosis and is the most infectious type. The mycobacterium
tuberculosis bacterium can also affect the stomach, bones, glands, and nervous system as well.
Infection with tuberculosis is transmitted through the air. Coughing and sneezing release bacteria-
containing droplets into the air. Infection with tuberculosis is more common in developing countries.
Countries like the United States and the United Kingdom rarely experience the disease. In 2019, south
east Asia had the largest number of tuberculosis cases in 2019. While anyone can contract the disease,
adults are most likely to be infected. In addition, HIV-positive people have 18 times higher risk of
contracting it, as do people with chronic illnesses that compromise their immune system. In most
healthy people, the immune system destroys bacteria, so there are no symptoms. Despite its limitation,
the immune system manages to prevent bacteria from spreading throughout the body. In other words,
you won't be affected because the bacteria will live in your body. Therefore, you would be considered
to have latent tuberculosis. Those with latent tuberculosis are not capable of spreading it from person
to person. however, as a result of an ineffective immune system, active tuberculosis can develop when
the bacteria spreads throughout the body.
The most common symptoms developed by having tuberculosis may include a persistent cough that
lasts longer than three weeks, bleeding phlegm, weight loss, night sweats, high temperatures, fatigue,
and swelling that has not subsided.
Life cycle of tuberculosis: There 5 stages of developing tuberculosis
1. Onset (1 – 7 days) the bacteria is being inhaled.
2. Symbiosis (7 - 21 days) if the bacteria is not killed then it reproduces.
3. In the initial caseous necrosis phase (14-21 days), the bacterium slows down its reproduction,
killing the surrounding non-activated macrophages and running out of cells to divide. Anoxic
conditions and a lower pH are created, which prevent the bacteria from reproducing.
4. After 21 days, the interaction between tissue damage and the immune response activated by
macrophages: The tubercle is surrounded by macrophages, some of which may not be active.
Then, when tuberculosis utilises it to replicate, it grows. The tubercule may separate and
disperse. Miliary TB is the term for tuberculosis that develops outside of the lungs if it
travels through the blood.
5. 5. Liquification and Cavity Formation: At some point, the tubercules will liquify, causing the
disease to spread more quickly. However, not everyone will reach this stage. Only a small
percentage of individuals will progress to this point.
, Diagnosis: The Mantoux tuberculin skin test can be used to check for tuberculosis. tuberculosis
infection: further testing is necessary to confirm TB illness. A tiny amount of a fluid called tuberculin
is injected into the skin on the lower section of the arm to perform the Mantoux tuberculin skin check.
Adding on to that, the initial diagnosis for Tb could be performed utilising a fast molecular diagnostic
test. This is justified by the fact that these tests' accuracy is quite high and they can aid in both the
quick identification of TB and drug-resistant TB. The anti-tuberculosis drugs rifampicin and isoniazid
are ineffective against the bacteria that causes multi-drug resistant TB. Also, diagnosis is more
difficult and expensive than conventional TB.
Treatments for Tuberculosis: Both prevention and treatment are options for tuberculosis. Take your
medications as directed and attend all of your doctor's appointments to avoid Tuberculosis. A six-
month antibiotic regimen is used to treat the form that responds to medication. Since some
Mycobacterium tuberculosis strains are resistant to certain types of medicines, a variety of antibiotics
may be prescribed for the treatment of TB. Isoniazid, revamping, ethambutol, and pyrazinamide are
examples of antibiotics. For at least six to nine months, these antibiotics must be taken consistently to
prevent the development of active TB. People who have Tb may go for a long time without receiving
treatment because their symptoms aren't serious enough to worry about and they may not even be
aware they have the condition. Nearly all HIV positive people and about 45% of HIV negative people
can die as a result of this.
Effects of TB on the human body: TB generally has an effect on the lungs as well as other body
organs like the brain, kidneys, and spine. Because the lower and middle lung lobes are often where the
bacteria-carrying inspired air is dispersed, these areas are frequently affected by primary tuberculosis.
The TB bacilli and infected macrophages that were ingested by them in their lungs form a rounded
complex with healthy macrophages surrounding the centre. The lymph nodes nearby are frequently
also infected by TB bacilli, which is known as a Ghon focus. The airways may be obstructed by
enlarged lymph nodes, leading to lung collapse. Therefore, symptoms like coughing and bleeding
phlegm may occur as the patient can’t breathe in air properly causing coughing. The primary complex
is made up of a complex in the lung tissue and an infected local lymph node. However, If the immune
system is strong, the primary complex recovers and just a little cavity and a tissue scar remain after
healing. This scar, which can later be detected on X-rays, indicates that the person has had a
Mycobacterium TB infection. Subsequently, if the immune system is not strong once the TB has let
itself be ingested by the macrophages into a vacuole and being broken down. It stops the cell from
breaking it down and bursts the cell hence the patient feels fatigued and has fever.
