May 09, 2024
Brittany Hosea-Small/USA TODAY NETWORK
Presidential candidate Robert F. Kennedy Jr. on stage during a campaign event in Oakland in March. It recently came to light that he said in 2012 that doctors found a worm in his brain.
A local infectious disease specialist explained Thursday that many different types of parasites can enter and live in the brain.
"But the good news is, most of the time this happens ... people are never aware of it, and it never bothers them," said Dr. Lawrence Livornese, who is the chairman of Main Line Health’s Department of Medicine.
The discussion was in response to news that broke Wednesday that Robert F. Kennedy Jr. had said in a 2012 deposition that a spot that had appeared on his brain scans "was caused by a worm that got into my brain and ate a portion of it and then died." He said this parasite was one of several conditions that may have been causing "cognitive problems" around the time of the deposition, which was taken during Kennedy's divorce proceedings from his second wife, according to the New York Times.
"I can't comment about him because I don't know about his health," Livornese said. "I don't know what he means when he says 'a worm.'"
But Livornese did help demystify how parasites enter and live in our bodies, most of the time with little consequence.
People can contract one of the most common type of parasite infections, toxoplasmosis, by eating undercooked meat or coming into contact with cat feces.
The parasite is dangerous during pregnancy because it can pass to the baby. People living with HIV/AIDS, people undergoing treatment for cancer, people with organ transplants and others who are immunocompromised are at risk for disease from infection with the parasite.
But most people with toxoplasmosis remain asymptomatic.
"Probably 60% of us, if we tested our blood, have antibodies against toxoplasmosis," Livornese said.
Antibodies are proteins the body produces when it detects an unfamiliar pathogen, such as a parasite.
"In healthy people, (toxoplasmosis parasites) sit there quietly and don't pose any problem with your immune system that controls them," Livornese said. "Sometimes they just die."
In immunocompromised people, sometimes toxoplasmosis can cause serious diseases in the eye, lungs or brain.
When the infection spreads to the brain, "there's nowhere for the brain to expand," Livornese said. "So if you get swelling, it starts to compress the brain, and that affects your ability to think. You can have seizures or go into a coma or die."
Larval cysts of the pork tapeworm, another type of parasite that can infect parts of the human body, can spread if someone eats undercooked, infected pork and develops an intestinal parasite. They can pass the parasite to another person by failing to wash their hands and then sharing food, for instance.
Larval cysts in the brain can cause a more serious condition called neurocysticercosis, which is the leading cause of adult onset epilepsy worldwide and can also cause death.
Scientists have classified neurocysticercosis as a "neglected tropical disease" that is preventable. Each year, there are approximately 1,000 new hospitalizations for neurocysticercosis in the United States.
Still, in the wake of the RFK Jr. news, people should not be too worried about parasites entering their brains.
"We're often accidental hosts" of parasites, Livornese said. "They're really looking for other animals, and they end up in us."
He did say that he had two worms that he had unearthed from people's bodies, preserved in jars of formaldehyde, sitting on his desk, including a "12-inch-long worm that looks very similar to what you would consider an earthworm." He had removed it from someone's colon.
They are teaching tools, Livornese said.
