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Source of infections - bacteria, viruses and fungi.

Free essay example:

Moshin Fazil

Mr Frimpong

Unit 21.2

Source of infections

Assignment 21.2 (Merit)


Bacteria are a common source of infection which can multiply with an incredible amount within a minute.  Bacteria can live on a living animal as well as a human due to the conditions; warmth, vitamins, minerals and sugars.

There are stages that occur before the bacteria takes full effect on the human body. Headaches and fevers will appear this is because the bacteria cells are damaging the human body cells within a body causing an illness.

Bacteria can cause a source of infection by a direct Contact, contaminating water that is dirty. This can cause a lot of illnesses; Cholera and typhoid. Dust from the air and any sort of bites from a mammal to an insect. Mosquitoes usually have infections that spread due to containing a bad blood type from a previous person which is then passed on to another person causing illnesses.

This can also be cured due to the pathogens within a human body. The pathogens can fight the bacteria cells and remember them so that if the same cells enter the body the pathogens can fight the cells. Pathogens are a defence for the human body without it the human body will not be able to fight the bacteria cells.

Bacteria sources of infections

  • Syphilis
  • Skin infections

Modes of transmissions

  • Contact, by a mammal or insect; will have to have a contact with the person.

Methods of entry in the human Body

  • Bites from mammals to insects
  • Dust from the air
  • Contamination of water which is dirty
  • Cuts on the human body which can let in bacteria.


Viruses are too small to be seen by the eye on its own (naked eye) They can't multiply on their own, so they have to invade a cell and take it over in order to be able to make more virus particles.

Viruses consist of genetic materials usually DNA; surrounded by a protective coat of protein. The cells of the mucous membranes, such as those lining the respiratory passages that we breathe through, are particularly open to virus attacks because they are not covered by protective skin.

Virus sources of infections

  • Cold
  • Measles

Modes of transmission

  • Droplets, can spread by another person coughing, sneezing or a direct talk with the person.

Methods of entry in the human body

  • A person with a cold can spread the infection by coughing or sneezing.
  • Viruses can be passed on by touching or shaking hands with another person.
  • Body fluids such as blood, saliva and semen can contain the infecting organisms for example by injection or sexual contact, is important, particularly for viral infections like hepatitis or AIDS.

Fungi (Fungus)

Can spread through the spores; the spores enter the human body if the body is not in its correct condition. For example cuts can let in spores.

The damper and darker it is the more it spreads within a human body. Its dark and very wet as well as the warmth is just right for the spores to develop.

Animal has flakes within their skin when there is a direct contact fungi can get within the skin and cause an infection

Source of infection

  • Athlete's foot
  • Jock itch

Modes of transmissions

  • Direct contact – with an infected person, animal or soil.

Methods of entry in to the human body

  • Mainly against skin; soil.
  • Contact with an animal that is carrying fungi spores.
  • Contamination of fungi.
  • Cuts can let in spores which creates fungi infections.
  • Walking bare feet in a swimming pool, shower area or a sauna.

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