Some microbes can be harmful to humans and can cause disease: the Influenza virus causes the ‘flu’ (short for ‘Influenza’ – other respiratory tract infections (RTIs) that cause similar symptoms are the ‘common cold’ or ‘influenza-like illness’), Campylobacter bacteria can cause food poisoning and the dermatophyte fungi, such as Trichophyton, can cause diseases such as athlete’s foot and ringworm. Microbes like these are known as pathogens. Each microbe can make us ill in different ways.

Someone who is ill because of a harmful disease-causing microbe is said to be infected. Many harmful microbes can pass from one person to another by a number of different routes – air, touch, water, food, aerosols (such as sneezes and water vapour), animals, etc. Diseases caused by such microbes are said to be infectious diseases.

In this lesson, students explore what microbes cause well known diseases, and the symptoms, transmission, preventative measures and potential treatments for each disease.