Diseases Caused by Microorganisms

1. There are many types of diseases with many different causes.

2. Many diseases are caused by microorganisms like bacteria and viruses. Some are caused by fungi and protozoa.
     
      Diseases caused by microorganisms

• Bacteria - Cholera, Conjunctivitis, Mumps, Scabies
• Virus - AIDS, Flu, Cough, Measles, Chicken pox
• Fungi - Ringworm, Tinea
• Protozoa - Malaria

3. Diseases caused by micro organisms can spread from one person to another. These are called contagious diseases.

4. A contagious disease can spread through different ways such as air, food or water and direct contact.

5. Air
(a) Microoganisms are very small and light.
(b) Thus, when an infected person sneezes or coughs, these microorganisms are released into the air. Healthy people may inhale these microorganisms and get infected.
(c) An example of a diseases caused by fungi such as ringworm and tinea.

6. Direct contact
(a) Direct contact with a sick person can cause the microoganisms to spread and cause infection.
(b) Measles can spread from one person to another by direct contact such as shaking hands.
(c) The sharing of clothing or personal items such as towels, may lead to the spread of diseases caused by fungi such as ringworm and tinea.

7. Food or water
(a) Some diseases spread when people drink water containing harmful microorganisms. Cholera, caused by a bacterium, can spread this way.
(b) Other diseases spread when people eat food containing harmful microorganisms.
(c) Food which are not covered is exposed to microorganisms in the air. If a person eats the food, he will get infected.
(d) Food can be infected if it is prepared or handled in an unclean way, for example, handling food with dirty hands.