What would happen if a person ate food that has fly eggs?

The fly eggs wouldn’t make you sick,nor would you have gotten maggoty. You might have gotten sick because the food had spoiled, food left out that long has had plenty of time for bacteria to grow.

They could cause intestinal myiasis where the eggs hatch in the gut.

I don’t know what would happen if you ate the fly eggs but the sight of those eggs already indicated that the food was spoiled, or at least had been “used” by flies. Now you have the answer.

I suspect that all of us at some point in our lives have eaten fly eggs, and possibly worse.

There are standards for how much of this stuff is allowed in food.

@josie and @Adirondackwannabe FTW.

There is no such thing as “perfectly untainted” food, no matter how fresh or carefully prepared. There are acceptance criteria, however, for “how much is too much”.

A prepared lunch that had been left in the open air, whether covered or not, for over four hours (from lunchtime to quitting time at most offices) would have caused more risk from bacteria, as @zenvelo noted, than any insect infestation.

Finally, to answer the direct question – and maybe with an answer that you don’t like, but which follows from the above – practically everything that you eat has some infestation of some kind, and usually nothing happens. In days before refrigeration, maggoty food was common on ships, where new supplies could not be obtained on long voyages, and most of the sailors were not sickened by that. The acceptance criteria for “how much infestation is allowable” is far, far below what people have dealt with in the past.

As far as fly eggs go, your stomach acid, I presume, would destroy them. They could never hatch inside you. As already stated, I’d be a lot more worried about bacteria from spoiled food.