A tapeworm capable of causing an epilepsy-inducing brain infection is more common on Long Island than previously thought, a team of Stony Brook University scientists has found.
Two relatively recent parasite-related epilepsy cases diagnosed at Stony Brook inspired two physicians, Drs. Amy Spallone and Luis Marcos, to investigate how many other instances of the infection have occurred on Long Island. Their study uncovered more than three dozens cases — far more than the doctors expected — over a decade.
They attribute the tropical infection to changing demographics in the region.
“Whenever you have a large population of immigrants you will see it. We found 44 cases that occurred over a 10-year period on Long Island,” Marcos, a specialist in infectious diseases, said Monday.
He and Spallone said the parasite is not a public health threat in this country and there are no chances of it spreading. But it is a danger to people who contracted it elsewhere in the world and carry the worm, its eggs or larvae in their bowel, blood or brain.
The doctors are concerned because the organism, a tapeworm known as Taenia solium, is a significant cause of epilepsy that emerges in adulthood, even if the infection occurred when the patient was a child.
“We want doctors to be on the lookout for this as a cause of epilepsy,” Spallone, a resident in internal medicine, said.
Tapeworm infections can be effectively treated with a monthlong course of anti-parasitic medication, Marcos said.
Precisely how people become infected is a study in the life cycle of a parasite that can have a portion of its existence in a pig and the rest in the human intestine and brain, the doctors said.
Spallone said the worm is a parasite of swine, affecting pigs in many parts of the developing world, mainly Central and South America, Asia and Africa. The worm can thrive in undercooked pork from which it can be ingested. T. solium, the physicians said, does not infect swine in this country.
However, it can persist in the intestines of humans, where it uses “hooks” on its head to grasp the inner bowel. There, it produces offspring that can escape into the bloodstream, its conduit to the brain.
The tapeworm essentially evades destruction by the immune system and remains a silent threat until a seizure occurs, Spallone said.
“When the larvae makes it way to the brain, it encysts,” said Spallone, referring to the larvae encasing itself in a protective covering. “A patient can have this larvae in the brain for years,” she said.
Spallone and Marcos recently reported the findings of their research at a scientific meeting in New Orleans. The 44 Long Island cases occurred between 2005 and 2015. Prevalence was slightly higher among males compared with females, the doctors said.
Although infections can occur in anyone from endemic regions of the world, the doctors found T. solium cases primarily among people from Latin America, probably because of immigration patterns on Long Island.
“We have no way of quantifying how many people may be affected because one of the conundrums is that we don’t see these patients until there is a major brain catastrophe,” Spallone said.
In the developing world, the parasites are usually prevalent in households, where the organisms are transmitted through the fecal-oral route, said Marcos, explaining that the worms exist in stools and are passed with unwashed hands.
“One of the cases we saw at Stony Brook last year required major brain surgery, otherwise the patient would have died,” Marcos said. “Primary care physicians should be aware that any seizures in people from endemic countries might be caused by infections in the brain.”
Stony Brook doctors have found dozens of cases of seizures caused by a brain parasite. A majority of local cases have occurred in people from Latin America. The worm, called Taenia solium, can be transmitted in undercooked pork.
- All local cases occurred in people who contracted the worms abroad; swine in this country do not harbor T. solium
- Tape worm infects the human intestine, but worm larvae escape via the blood to the brain
- Larvae in the brain are encased in “cysts” that can persist for years
- Cysts can cause seizures and scar tissue
- Tapeworm infections can be treated with a monthlong course of antiparasitic medication.
- Infection can impede circulation of cerebrospinal fluid in the brain, causing hydrocephalus, too much fluid in the organ. Surgery is required to relieve excess fluid.
SOURCES: Drs. Luis Marcos and Amy Spallone, Stony Brook Medicine