Question for microbiologists/immunologists regarding eating other people's food

I'm no microbiologist, but I went on a trip to Spain and shared pizza with a friend at the airport before coming back. She got really sick (not food poisoning, but a cold) shortly after we got back, but I was fine.

Chilling won't kill anything, it just slows down the metabolism/growth of any bacteria on the food. Heating would likely kill most or all of the bacteria present on the food, but if it's contaminated with E. coli or something, it's probably full of toxins that will make you sick. This shouldn't be a problem unless the food is pretty old though.

The cold and flu are caused by viruses, which aren't alive so they can't be "killed." I'm not sure how much heat is necessary to denature them, but if your kids aren't sick, you're probably okay.

Guppy wrote:

The cold and flu are caused by viruses, which aren't alive so they can't be "killed." I'm not sure how much heat is necessary to denature them, but if your kids aren't sick, you're probably okay.

So if there is a virus on a plate or food, does it sit there indefinitely?

you said it wrote:

So if there is a virus on a plate or food, does it sit there indefinitely?

Viruses are just bits of DNA or RNA encapsulated by protein. By heating them or subjecting them to certain chemicals, you can denature ("kill") them, or you can just scrub them off when you do the dishes and they'll go down the sink. I think you may be worrying too much about this. I've eaten out of the same bowl almost every day for the past 15 months, usually only rinsing it out when I'm done, and I almost never get sick. I can't remember the last time I was sick actually. Again, don't worry about it and use common sense. If your kid is sick, don't eat their food. If your kid isn't sick, go ahead. People aren't usually very contagious during incubation periods (the time when they're infected but haven't yet shown any symptoms).

Anyone with some real knowledge on this, feel free to chime in and correct me if I'm wrong.