Reply #24: Point her to the CDC website.

[Ms. Toad]

Of course, they haven't really tested it with the H1N1 virus - but the standard period for the flu at which your viral load is high enough to be a risk to anyone (other than immune compromised people) is 24 hours before the first symptoms through 24 hours after your last fever over 100 degrees (without taking meds designed to lower your fever).

To be on the safe side, the CDC added the minimum of 7 days (although on checking, it appears they have now reverted to just 24 hours after the fever breaks which could be considerably less than 7 days. When I had it at the end of October/beginning of November they were using the minimum of 7 days figure).