Myiasis? Avoid flies and mosquitos, and don't eat anything flies have been on. Accidental myiasis is where non-parasitic maggots end up inside you and survive somehow. Very rare, but only possible if you let the eggs in first. Deliberate myiasis is caused by certain flies, such as botflies, which have particular ranges. They catch mosquitos and attach an egg to it. The egg hatches when the mosquito lands on a person and the tiny maggot enters the skin through the bite hole and grows there.

Tapeworm cysts result from tapeworm larvae, which hatch from eggs. Regular worms result from the consumption of cysts, but cysts result from the consumption of eggs. Eggs are produced by adult worms in the guts of animals and humans, and pass in the faeces. So don't eat any grass off of the floor where animals are kept, and don't eat any food that has been touched by someone who didn't wash their hands after using the toilet without it going into the oven first. Cases of brain cysts usually occur from eggs on restaurant salad, inadvertently placed there by infected chefs who don't practice even minimal hygiene.