The reasons why influenza affects communities in waves of infection have been discovered by researchers from McMaster University.
To collect information, researchers scoured available historical documents and collected data about weekly influenza deaths from the deadliest influenza pandemic in history, known as the Spanish flu, which hit England and Wales in 1918.
Three factors contributing to the spread of the flu include the closing and opening of schools, temperature changes and – most importantly – changes in human behaviour.
Read more at McMaster University