Infection with influenza at various points in one's life is inevitable, unless one happens to live in an extremely remote and isolated community.
Flu viruses are highly contagious and spread easily:
- In the general community, pre-school and school children are most likely to get flu. This is because children have little pre-existing immunity and are highly susceptible to the viruses, which they then bring home to their families. The highest infection rate is amongst school aged children younger than 10 to 12 years, and amongst people in old age homes.
- Closed communities, such as homes for the elderly, university campuses and military bases, are prone to outbreaks of influenza, which run their course over a few weeks.
- About 21 percent of people living in the same house as an infected child or adult, will contract flu, according to American studies.
- About 6 percent of people exposed to influenza outside the household, will get flu.
- About 30 to 50 percent of asymptomic people (those who are infected but show no symptoms) transmit the flu virus to others.
Reviewed (2006) by Dr Jane Yeats MBChB, BSc(Med)(Hons)Biochem, FCPathSA(Virology).