I prefer my fish cooked

It's been quite a while since I've noticed any article about catching parasitic worms from eating raw fish, but here's one which goes into a lot of interesting detail:  

Parasitic Worms Burrow into Walls of Woman's Stomach After Meal: The worms can burrow into the walls of the stomach or the small intestine, though it is much more common to find them in the stomach, Fuchizaki said. About 95 percent of anisakiasis cases are in the stomach, he told Live Science.

When the worms burrow into the walls of the stomach, the symptoms usually develop within several hours of eating contaminated fish, Fuchizaki said. If the infection occurred in the small intestine, however, the symptoms wouldn't start until one to five days later, he said.

Some people may notice the worms even sooner than a few hours after eating raw fish — in some instances, people actually feel a tingling sensation in their mouth or throat while they are eating, which is caused by the worm moving around there, according to the Centers for Disease Control and Prevention. Some people may be able to remove the worm with their hand or by coughing, the CDC says. Vomiting, which is often a symptom of anisakiasis, can also expel the worms, the CDC says.

In most cases, people experience pain and other stomach problems because the worms are damaging the tissue of the digestive tract, Fuchizaki said. But some people may be allergic to the worms, and experience an allergic reaction if they eat them, he said.

Because the worms do not reproduce in humans, they eventually die and cause an inflamed mass, according to the CDC.