clipped from www.cdc.gov

Avoid Contact With Others

If you are sick, you may be ill for a week or longer. Unless necessary for medical care, you should stay home and minimize contact with others, including avoiding travel and not going to work or school, for 7 days after your symptoms begin or until you have been symptom-free for 24 hours, whichever is longer. If you leave the house to seek medical care, wear a facemask, if available and tolerable, and cover your coughs and sneezes with a tissue. In general, you should avoid contact with other people as much as possible to keep from spreading your illness, especially people at increased risk of severe illness from influenza. With seasonal flu, people may be contagious from one day before they develop symptoms to up to 7 days after they get sick. Children, especially younger children, might potentially be contagious for longer periods.  People infected with the novel H1N1 are likely to have similar patterns of infectiousness as with seasonal flu.