Brain worms like the one RFK Jr. had are real and more common ...

Brain worms, like the one Robert F. Kennedy Jr.'s campaign said he contracted more than a decade ago, are real — and the infections are more common in certain parts of the world than you might think.

On "CBS Mornings" Thursday, CBS News medical contributor Dr. Céline Gounder confirmed there are parasitic infections you can get in your brain. Tapeworm infections of the brain, or neurocysticercosis, can be contracted from consuming undercooked, infected pork or drinking contaminated water.

"Usually this happens in countries where you have poor sanitation, unclean water," she said, adding it is "one of the most common causes of seizure around the world where you don't have good water and sanitation."

Kennedy campaign spokesperson Stefanie Spear said in a statement to CBS News that the independent running for president contracted the parasite after traveling "extensively in Africa, South America and Asia as his work as an environmental advocate."

How do you get brain worms?

When people ingest microscopic tapeworm eggs, they hatch and become larvae that can infest various organs including the brain, muscles, liver and other tissues.

"The way this typically would happen is you have the parasite eggs in feces and then you're having food or water — your hands are contaminated with that — and that's how you end up with that," Gounder said. 

Kennedy said in a 2012 deposition that a parasitic worm "ate a portion" of his brain and may have caused cognitive issues, according to a New York Times report. But these parasites don't "eat to your brain," Gounder said.

"The most likely one that he would have is a pork tapeworm-related cyst, and those generally will stay in place. They might grow, cause inflammation or swelling, and that's how you get symptoms — but they're not eating your brain," she said. 

Brain worm symptoms

Symptoms can include nausea, vomiting, headaches and seizures, Gounder said, although many people who suffer from this type of infection may not see symptoms. 

Treatment for tapeworm infection typically involves medications such as anti-parasitic drugs to kill the worms. In some cases, if the worm dies, the body's immune system may clear the dead worm from the brain tissue without requiring surgery, unless complications arise. Kennedy told the Times that no treatment was necessary for his parasitic condition.

Gounder said usually these parasites get "walled off by your immune system and they get calcified."

"So for most people, they probably don't even know they have this," she said. "It's only when they develop symptoms like seizures or headaches. Or maybe incidentally, it's picked up on a scan that you're having for some other reason."

-Allison Novelo contributed reporting.

More from CBS News