Pages 4 (986 words)
Causes of Infectious Diseases
Differences between bacteria, viruses, fungi and parasites
Bacteria, fungi and parasites are all considered as ‘living’ things,. Bacteria are single celled microorganisms that can only been seen through a microscope, they collect their nutrition from their surrounding and unlike viruses, they do not need a living host to reproduce. Viruses are difficult to destroy because they are enclosed in a protein coating. Viruses are disease-producing agents, far smaller than bacteria. Viruses are not considered as living because they are unable to reproduce.
Fungi are placed into the plant category although they are very different from green plants. The basic part of fungus is a hollow tube, which is known as ‘hypha’. Fungi spread by releasing spores into its surroundings. Parasites are an organism that feeds and is dependent of its host.
Common illnesses and infections caused by bacteria, viruses, fungi and parasites
Common illnesses and infections caused by bacteria include:
- Bacterial meningitis,
- Lyme disease,
- MRSA infection,
- Scarlet fever,
- Typhoid fever, and Urinary tract infections.
Common illnesses and infections caused by viruses include:
- Common cold,
- Hand, foot, and mouth disease,
- Viral hepatitis,
- Influenza (Flu),
- Viral meningitis, and Viral pneumonia.
Common illnesses and infections caused by fungi includes:
- Pneumocystis pneumonia,
- Fungal meningitis,
- Candida infection,
- Ringworm, and Athlete’s foot.
Common illnesses and infections caused by parasites include:
- Stomach and gut worms (Threadworm, hookworm),
- and Hair and body lice (Head and crab lice).
What is meant by ‘Infection’ and ‘colonization’
Infection means that the body is being invaded by bacteria, viruses and parasites that are not usually there, these are known as microorganisms.
Colonization is a bacterial infection manifesting on or in an individual, making the individual the carrier of the infection who may not necessarily have any signs or symptoms of the illness, however they do still have the potential to infect others.
What is meant by ‘systemic infection’ and ‘localized infection’
Systemic infection means the infection is in the blood stream, and is or has spread through the body. Lime Disease, AIDS, Tuberculosis and Septicemia are examples of Systemic infections. Localized infection means the infection is restricted to one area on the body i.e. small cut or ulcer that is infected. However if a localized infection becomes worse, and no medical treatment is given it could spread and become a systemic infection.
Poor practices that may lead to the spread of infection
- Not washing your hands after having contact with service users, food, hazardous substances, using the toilet etc.
- Not wearing the correct PPE when needed
- Not storing food correctly
- Not cooking food thoroughly
- Not covering your mouth or nose when sneezing or coughing
- Poor waste disposal and storage procedures
- Inadequate cleaning/decontamination of environment and equipment
Conditions needed for the growth of micro-organisms
Four key factors are needed to make the perfect environment for microorganisms to grow, these include; moisture, nutrients, warmth and time.
- Moisture — moisture is essential to carry foods in solution into the cell, and carry the waste away from the cell.
- Nutrients — lack of food slows down the bacterial growth, therefore the sufficient nutrients are needed.
- Warmth — temperature plays a big role in the growth rate of the bacteria. Micro-organisms that are exposed to adverse temperatures are either destroyed or not able to multiply.
- Time — time to reproduce.
The ways an infective agent might enter the body
- An infective agent might enter the body through the nose, windpipe or lungs (respiratory tract into the lungs) this is how coughs, colds and other common airborne infections are contracted.
- Infective agent may also enter the body via breaks in the skin, bites, scratches; puncture wounds from needles etc. will increase the risk of infection.
- Infective agent can enter the body down the digestive tract (stomach, mouth and intestines). Swallowing contaminated foods or drinks can infect the stomach and bowels, which shows itself in the form of diarrhea and/or vomiting.
- Infective agent can also enter the body up the urinary and reproductive systems (urethra, bladder and kidneys). The infectious agent will remain localized until/ if it enters the blood stream.
Common sources of infection
Common sources of infection include food, water, sick people (colds and flu), animals and poor housing (invaded with pests such as rats and mice or damp and moldy), contaminated food, drinks, bodily fluids; vomit, tears, breast milk, urine, blood, mouth, nose, sweat and broken skin.
How infective agents can be transmitted to a person
The different ways that infective agents can be transmitted to a person include,
- Droplet contact; meaning when someone is coughing or sneezing near/on another person and not covering there mouth or nose.
- Direct contact; meaning touching a person who is infected, this also includes sexual contact.
- Indirect contact; meaning to touch a contaminated surface or soil contamination without realizing it is contaminated.
- Airborne transmission; means that the microorganisms can remain in the air for long periods of time.
- Fecal-oral transmission; which means the foods or waters you intake is contaminated.
- Lactogenic transmission; means after medical procedures via injection or transplantation of infected materials.
- Vector-borne transmission; this does not cause the disease but instead transmits pathogens from one host to another.
- Vertical transmission; means the mother passes on the infection to her child, either in the uterus or during childbirth.
- Sexual transmission; infection being passed of through sexual contact with another person.
Key factors that will make it more likely that infection will occur
The key factors that will make it more likely for infection to occur include:
- immunity being low due to already being ill or even vrey young or old age,
- not being immunized,
- open wounds,
- poor practices such as poor housekeeping and misuse of PPE,
- poor personal hygiene,
- contaminated areas/surfaces and contaminated equipment or laundry,
- people living in the same environment such as a care home setting where many people share the same facilities, equipment, and washrooms.