No matter HOW cautious one is; S happens. You think you're better and realize; Nope! Or you don't even know you're sick and realize it after being around people.
It happens to ALL parents at least a handful of times. ((I call it the "groan and phone")). So those of us who don't have kids on chemo/organ transplant tend to be pretty forgiving ((those parents, however, MEAN it when they say a week or more with no symptoms)).
How long to WE wait? Depends on whom we are to interact with.
- Healthy adults and older children = 2 days after no more symptoms. (You're about 70% safe at that point. Still shedding a bit, but healthy immune systems can deal without 'catching' it the vast majority of the time.)
- Infants, young children, the elderly and other immunocompromised people = 1 week OR longer.
- Summer Flu (we get the seasonal 'winter' flu early, because our friends return home from the middle east, carrying the flu with them and so we get it a few months before the flu shot makes it's way west -the seasonal flu starts in asia a whole year before it makes it here, and the flu shot travels with it about a month ahead... production issues... there's just no way to make half a billion shots all at once, it's a RACE to keep ahead of it... as people saw when it started close to home last year instead of where it usually does in asia. Anyhow, they bring it over, we catch it early and have to quarantine ourselves) = 10 days.
It SUCKS. My son's uncles just brought home their baby girl 2.5 months ago, and we haven't seen neither her nor them in 2 months. We've just been round robining will colds/flus (and then my son was hospitalized for a week with a mystery illness)... so we've REALLY been staying out of circulation. Poor them, however... mutual friends brought their sick son over (the bring him EVERYWHERE with full on fevers, actively vomitting, snot everywhere all the time... it's really near ruined our friendship because they're just willfully IGNORANT, self centered, blah blah blah) because he "just" had a cold... and she rocketed up to 105/ 106... needed IV fluids, and was just deathly ill for 4 days, and has been miserable for 2 weeks because of their son's "just" a cold. ((I want to wring their necks)). BUT they do it ALL the time.