Causes and spread of infection
The difference between bacteria, viruses, fungi and parasites are: Viruses are coated genetic material that invade cells and use the cell's apparatus for reproduction.
Bacteria are single celled organisms. Some classify them as a separate (fourth) kingdom on the tree of life.
Fungi are multi-celled organisms that form a third Kingdom of life, along with the plant kingdom and the animal kingdom.
Parasites are plants or animals that derive benefit from the metabolism of other plants or animals at the expense of the host and without providing some benefit to the host in return.
Common illness and infection caused by bacteria, viruses, fungi and parasites are:
Bacteria: Food poisoning, Bubonic plague, Bacterial meningitis, Cholera, Diphtheria, Rheumatic fever, Scarlet fever, Tuberculosis
Viruses: Chicken pox, Hepatitis A, B, C and HIV, Influenza, Measles, Mumps, Shingles, Yellow fever
Fungi: Athletes foot, Thrush, Tinea (Ring worm)
Parasites: Malaria, Tape worm, Head louse, Bed bug, Body louse
The meaning of infection and colonisation
Infection is an invasion of the body by a foreign substance such as germs, microbes and parasites these can infect the body in many different ways.
Colonization is the development of a bacterial infection on an individual, as demonstrated by a positive culture. The presence of the bacteria on a body surface (like on the skin, mouth, intestines or airway). The infected person may have no signs or symptoms of infection while still having the potential to infect others. Infection begins when an organism successfully colonizes by entering the body, growing and multiplying.
The meaning of systemic infection and localised infection are Systemic infection means it has infected the whole body, spreading possibly through the blood to all parts of the body causing an all over infection. Localised infection means the infection stays in one place more likely where the infection enters