Communicable Disease

• Pathogens are microorganisms that cause disease in humans or animals. They can be easily spread.
• The four types of pathogens are: Bacteria, Viruses, Fungi, Protists
• Bacteria are very small cells which can reproduce in your body very fast. They produce toxins (poison) that damage your cells and tissues which makes you ill.
• Viruses are not cells.
• Viruses can reproduce in the host cell and cause damage to the cell. It replicates itself until the cell bursts and this cell damage makes you feel ill.
• Protists are single-celled eukaryotes.
• Some protists are parasites. Parasites live on or inside other organisms and can cause them damage. They are often transferred by a vector e.g. mosquitoes can carry malaria
• Some fungi are single-celled while others have a body made up of hyphae. Hyphae can grow and penetrate human skin and the surface of plants, causing disease.
• Pathogens can be spread through the air, water, or direct contact with an infected person.