Contains the full lesson along with a supporting toolkit, including teachers’ notes.
What is Influenza and How are People Infected?
Influenza (Flu) is a viral disease mainly affecting epithelial cells of the upper respiratory tract. It is a major cause of mortality and morbidity amongst the elderly and those with chronic medical conditions that make them more susceptible to infection. The virusdamages mucus-producing and ciliated cells, which are responsible for killing and expelling bacteria from the respiratory tract. Consequently, influenza brings the risk of opportunistic infections requiring antibiotic treatment; however antibiotics have no effect on the influenza virus itself.
Influenza spreads from person to person by airborne droplet infection (coughing/sneezing) or contact with contaminated surfaces. Coughing and sneezing are unavoidable and good hygiene practices reduce the risk of transmission. Detergents applied to surfaces kill the virus. Viruses do not survive for long outside a host.
Epidemic risk is greater in winter. In the Northern Hemisphere, influenza season commences in November and continues through to April whilst in the Southern Hemisphere influenza season runs from May to October. Viruses survive longer in cold conditions when the absolute humidity is low.
How Does Influenza Differ from the Common Cold?
The main difference between influenza and the common cold is that the symptoms of influenza come on rapidly and are typically accompanied by muscle aches, headaches, general tiredness and a fever. The common cold has a more gradual onset and is associated with a runny nose and sneezing. Flu normally runs its course in two to seven days but people may be infectious before symptoms appear and remain so for several days; children are particularly infectious.