These Brain Parasites Are More Common Than You'd Expect

Parasitic brain infections may be the subject of many a horror flick, but presidential candidate Robert F. Kennedy Jr. says this was his reality back in 2010, according to contents of a 2012 deposition (via The New York Times). The 70-year-old politician sought medical care after a friend expressed concern over significant symptoms of brain fog and memory loss. While some experts attributed the abnormalities in his scans to a tumor, another doctor felt it "was caused by a worm that got into my brain and ate a portion of it and then died," Mr. Kennedy was documented as having said at the time. Exactly what kind of brain parasite Mr. Kennedy may have had was never determined, but it certainly has raised questions as to whether these types of infections might be more common than we think.

Depending on the type of parasite, certain brain infections may be more common in the United States than others. While Scientific American reports that parasitic brain infections are not often seen in the U.S., Dr. Peter Hotez, professor of pediatrics and molecular virology and microbiology at Baylor College of Medicine, told U.S. News & World Report that cases of toxocariasis and neurocysticercosis — two kinds of parasitic brain infections — can be found well throughout the country. Here's what you'll want to know about each of these diseases.

While toxocariasis and neurocysticercosis share some similarities, they have their distinct differences. Toxocariasis infections are borne from the Toxocara roundworm, a parasite whose eggs can be found in contaminated dirt and soil (via U.S. News & World Report). If ingested by humans, the eggs can make their way into the intestines where the larvae may hatch. The parasite can then make its way into the lungs or brain, prompting respiratory issues, seizures, or developmental delays.

A few more steps are involved in cases of neurocysticercosis infection. Like toxocariasis, a tapeworm infection can also prompt seizures. If the tapeworm resides in the gut of someone in close proximity to you, and the person sheds the eggs through excrement, and you were to ingest the eggs, this can lead to neurocysticercosis. While living, the larval tapeworm sets up camp in the brain, unbeknownst to the body. Once the parasite dies, it can no longer evade detection by our immune system, which defends itself with an inflammatory response in the brain, subsequently prompting a seizure disorder. Scientific American adds that this infection stems specifically from the pork tapeworm, which humans may first become infected with from consuming contaminated pork that hasn't been properly cooked. Again, requiring a second step, a person would then need to ingest that individual's contaminated fecal matter to be susceptible to the brain infection — yet another reason to be vigilant about proper hand-washing.

The pork tapeworm is responsible for approximately 1,000 hospitalizations in the U.S. annually, with the majority of cases occurring in regions with higher rates of international travel, such as New York or California (via Scientific American). However, there's no need to bypass pork the next time you're perusing the meat aisle at the grocery store. Meat products undergo rigorous inspection in the U.S., and neurocysticercosis infections are more common in areas of the world where sanitation issues increase the risk of pigs contracting the parasite, according to the California Department of Public Health.

In reference to Mr. Kennedy's specific comments about a worm having "eaten" a portion of his brain, experts clarify that these parasites do not actually feed on our brains, but instead cause tissue damage. Doctors have various means of treating and diagnosing a tapeworm infection, and a representative from the Kennedy campaign told U.S. News & World Report that the infection is no longer a risk to the politician's health. "The issue was resolved more than 10 years ago, and he is in robust physical and mental health," press secretary Stefanie Spear told the publication.