Causes and Spread of Infection

                          Causes and spread of infection
1.1 Identify the differences between bacteria, viruses, fungi and parasites

Bacteria comes in 3 main shapes; spherical which are known as cocci, rod shaped which are known as bacilli or vibrio, and spiral which is known as spirilla or spirochetes. Bacteria is found in everything for e.g. soil, water, animals, plants, radioactive waste. The only place they aren’t found is where humans have sterilised. They can cause illnesses like tuberculosis, tonsillitis, and laryngitis and food poisoning

Virus is a toxin or poison. It is a microscopic organism consisting of genetic material.   They cannot reproduce without a host cell. When it gets this host cell, it takes over its functions.   The cells then continue to reproduce, and reproduces more viral protein. Several human diseases are caused by viruses which include:- smallpox, measles, the common cold, chickenpox, hepatitis, HIV, cold sores, shingles to name but a few. Viruses can spread from person to person, and by exchange of salvia, coughing, sneezing.

Fungi are skin infections caused by dermatophytes and yeasts, which are groups of fungi that are normally harmless. When these grow excessively, it causes symptoms and usually affects your skin because they live of keratin.   The different fungi infections are: - athletes foot which is itchy flaky red skin, nail infections which can discolour or make the nail crumbly and the thin thicker, ringworm of the groin which can be passed person to person by direct contact and   ringworm of the body which is like a red ring rash shape which is a contagious and caught by direct contact. There are also other fungi’s like thrush, yeast infection. Fungi infections can also be caused by antibiotics, pregnant, poorly controlled diabetes, weak immune system.

A parasite lives in close relationship another organism, its host and it causes harm. Viruses are common parasites. Parasites have to be in its host to live, grow and...