Worm Removed From Woman's Brain

April 13 -- An Arizona woman says she's feeling good, a little more than a week after undergoing six hours of surgery to remove a worm that had lodged in her brain.

Dawn Becerra and her doctors believe the parasite got into her system three years ago, when she ate a pork taco while on a visit to Mexico.

Becerra said she was ill for three weeks after eating the taco. Soon after, she began suffering violent seizures. Later, doctors determined she had a parasitic worm in her brain and it had caused neurocysticercosis — a lesion in her brain.

Poor Sanitation Allows Parasite to Spread

Doctors at Arizona's Mayo Clinic in Scottsdale believe the taco contained Taenia solium, a parasite that is common in Latin America. It can be transmitted by infected food prepared by someone who has not followed proper sanitation procedures after coming into contact with the creature's eggs, which can be present in human feces.

Some experts point out that it is difficult to know for certain that the taco was the source of the worm.

However Becerra ingested the parasite, it attached itself as an egg to her intestinal wall. Eventually, the egg developed into the worm, which moved into her blood stream and to her brain, said Dr. Joseph Sirven, who operated on Becerra.

Once in the brain, the worm causes little harm until it eventually dies and decays, thereby inflaming surrounding tissue.

"It's after the worm dies that the body reacts to something foreign," Sirven explained.

Undergoing Brain Surgery While Awake

Although Becerra seems to have kept a good attitude — she even gave the worm a nickname, Tonya — she said the seizures it caused were devastating. She reached a point where she could no longer tolerate them.

"You have to be conscious that you can have them at any time," Becerra told ABCNEWS' Good Morning America on Thursday, "and I lived with the thought that there was a worm in my brain."

She made the decision to have it removed and just when she thought the situation couldn't get any worse — it did.