A five-year study of influenza in families. Joint Public Health Laboratory Service/Royal College of General Practitioners working group.

A five year collaborative study of influenza in volunteer families from 1973-78 covered a period in which there were outbreaks every year but no major epidemics of influenza. Volunteers over the age of 15 years were bled before and after each of the five winters, and virus isolation was attempted from as many as possible when they reported episodes of illness. Children under 15 in the volunteer families were also swabbed when they were ill. Although most families experienced one or more attacks by influenza viruses, there was little transmission within families.