People with the flu are contagious starting about 1 day before symptoms appear and remain contagious for about 5 to 7 days after becoming sick. The period of highest contagiousness is generally during the first 3 days of illness. Some individuals, such as young children and people with weakened immune systems, may be contagious for longer periods. To summarize:
- Contagious from 1 day before symptoms start
- Most contagious in the first 3 days of illness
- Contagious up to 5 to 7 days after symptoms begin
- Children and immunocompromised persons may be contagious longer
You should stay home and avoid contact with others while contagious, especially until at least 24 hours after your fever has resolved without the use of fever-reducing medication
