Assignment of
Fundamental principles of infectious disease’s
Submitted by
Waqas Ahmad
Submitted to
Ma’am Zunaira Iqbal
Registration no
70110425
Date: November 9,2022.
What is Bacteria and its types?
Bacteria:
Bacteria are prokaryotic organisms, single-celled organisms. The nuclear membrane is absent in
bacteria, and they divide by binary fusion.
Bacteria can be categorized as gram-positive and gram-negative bacteria. Gram-positive
bacteria are Pedi coccus pentosane’s, Staphylococcus aureus and Streptococcus pyogenes.
Gram negative bacteria are Pseudomonas aeruginosa and Escherichia coli. Gram-negative
bacteria are more resistant to antibiotics than gram-positive bacteria, comparatively.
Types of bacteria:
Bacteria are divided into types depending on their size and shape. They are classified depending
on the three basic shapes.
1. Spherical-Shaped
2. Rod-shaped
3. Spiral-Shaped
Spherical-Shaped:
Bacteria shaped like a ball are called cocci, and a single bacterium is a coccus. Examples include
the streptococcus group, responsible for “strep throat.”
Strep Throat:
Strep throat is a sore throat caused by bacteria known as Streptococcus pyogenes, or group A
streptococcus. Sore throat is the general term for any condition where the throat feels, scratchy,
tender, and possibly painful. Strep throat, however, is a sore throat caused by a specific type of
bacteria.
Rod-shaped:
These are known as bacilli (singular bacillus). Some rod-shaped bacteria are curved. These are
known as vibrio. Examples of rod-shaped bacteria include Bacillus anthracis (B. anthracis),
or anthrax.
Anthrax:
Anthrax is caused by infection with Bacillus anthracis, a hardy, spore-forming bacterium that can
survive in extreme conditions for a long time. The bacterium is highly toxic.
Spiral-shaped:
These are known as spirilla (singular spirillum). If their coil is very tight, they are known as
spirochetes. Leptospirosis, Lyme disease, and syphilis are caused by bacteria of this shape.
Syphilis:
Syphilis is a sexually transmitted bacterial infection. It is treatable in the early stages, but without
treatment, it can lead to disability, neurological disorders, and even death.
Viruses:
Latin for “poison” or “slimy liquid”. A virus is a chain of nucleic acids (DNA or RNA) which
lives in a host cell, uses parts of the cellular machinery to reproduce, and releases the replicated
nucleic acid chains to infect more cells. A virus is often housed in a protein coat or protein
envelope, a protective covering which allows the virus to survive between hosts. Viruses not living
organisms because they do not grow or respond to their environment.
How viruses multiply:
Viruses can’t reproduce by themselves; they must use a host cell to make copies. Five steps to
virus multiplication:
1. Attachment
2. Injection
3. Production
4. Assembly
5. Release
List of viral diseases:
Following is a list of virus diseases that have made a significant socioeconomic impact in the last
few decades.
AIDS (acquired immunodeficiency syndrome)
Ebola
Influenza
SARS (severe acute respiratory syndrome)
Chikungunya
Small Pox (Now eradicated)
What are Infectious Diseases?
Infectious diseases are the diseases caused by various pathogenic microorganisms such as virus,
bacteria, protozoan, fungi, and other parasites. These infectious diseases can be transmitted by
animals, humans, insects or other agents.
List of Infectious Diseases:
1. Polio
2. Rabies
3. Mumps
4. Dengue
5. Plague
6. Malaria
7. Anthrax
8. Cholera
9. Measles
10. HIV/AIDS
11. Smallpox
12. Influenza
Types of Infectious Diseases:
1. Viral infections:
Viruses are a piece of information (DNA or RNA) inside of a protective shell (capsid). Viruses
are much smaller than your cells and have no way to reproduce on their own. They get inside
your cells and use your cells’ machinery to make copies of themselves.
2. Bacterial infections:
Bacteria are single-celled organisms with their instructions written on a small piece of DNA.
Bacteria are all around us, including inside of our body and on our skin. Many bacteria are
harmless or even helpful, but certain bacteria release toxins that can make you sick.
3. Fungal infections:
Like bacteria, there are many different fungi. They live on and in your body. When your fungi
get overgrown or when harmful fungi get into your body through your mouth, your nose or a cut
in your skin, you can get sick.
4. Parasitic infections:
Parasites use the bodies of other organisms to live and reproduce. Parasites include worms
(helminths) and some single-celled organisms (protozoa).
5. Transmissible spongiform encephalopathies (TSEs/prion diseases):
TSEs are caused by prions — faulty proteins that cause other proteins in your body, usually in
your brain, to become faulty as well. Your body is unable to use these proteins or get rid of them,
so they build up and make you sick. Prions are an extremely rare cause of infectious diseases.
How are Infectious Diseases Transmitted?
The infectious diseases are spread in the following ways:
1. When an infected person sneezes or coughs, the droplets containing the pathogen of diseases
such as influenza, common cold, etc. might spread in the air and infect others in the vicinity.
2. Touching an infected person, or their body fluids such as saliva, blood, sweat, urine, etc.
transfer the infections to a healthy person, e.g., chickenpox, measles, etc.
3. Touching the objects or areas touched by an infected person can transfer the infection to a non-
infected person and cause diseases.
Preventing Infectious Diseases:
Here are some of the practical ways which can be practiced for preventing the infection:
1. Vaccination
2. Use of antibiotics.
3. Maintaining proper hygiene.
4. Avoid travelling or going to work when you fall ill.
5. Avoid sharing used personal belongings such as a razor, glass, toothbrush, comb, etc.
6. Keeping your kitchen clean by washing all the used utensils, cooking area before and after
preparing each food.
7. Extra care needs to be taken while going to hospitals such as wearing a mask, using sanitizer,
etc.
