An 18-year-old man in India has died after doctors found parasites in his brain.
The unnamed teen, who lived in Faridabad, had been complaining of pain in the groin for about a week when he began experiencing seizures, according to a recent case study in the New England Journal of Medicine. His parents took him to the emergency department, where he showed signs of confusion as well as swelling over his right eye.
An MRI of his head revealed multiple lesions in his brain and brain stem and cysts in his right eye and testicle. Those lesions were Taenia solium parasites, the cysts were larvae.
Cysticercosis is an infection that occurs after a person swallows tapeworm eggs. The larvae get into tissues such as muscle and brain, and form cysts there. When cysts are found in the brain, the condition is called neurocysticercosis (NCC).
The teen was diagnosed with neurocysticercosis, the most common parasitic disease of the central nervous system. It’s linked to accidental ingestion of pork tapeworm eggs, often from raw or undercooked pork.
Despite treatment with corticosteroid and antiepileptic medication, the teen died two weeks later.
Neurocysticercosis accounts for about 50,000 deaths per year and is the leading cause of epilepsy worldwide, according to the Canadian Medical Association Journal. It’s becoming increasingly prevalent in industrialized countries, with increased travel to disease-endemic areas and the migration of tapeworm carriers or people infected with the disease, the CMAJ reports.
Here’s how you can get it: in some areas of the world, particularly those with insufficient sanitation systems, pigs serve as scavengers, consuming human feces that often contain T. solium eggs. Pigs become the intermediate hosts in the life cycle of the tapeworm, and infection in humans can occur from the consumption of improperly cooked meat.
Once in the brain, the parasite can remain almost undisturbed for many years.
The condition often shows no symptoms, but signs can include headache, vision problems, abdominal pain, dementia, and seizures. It’s not clear why some people experience late-onset epilepsy and others do not.
Dr. Jan Hajek, a clinical assistant professor in the division of infectious disease at the University of British Columbia’s faculty of medicine, says it is important to know that you don’t have to eat raw or undercooked pork to get neurocysticercosis.
People can also become infected by consuming water contaminated with tapeworm eggs or through poor hygiene practices — say, if someone who is infected doesn’t wash their hands then handles your food.
“People who eat infected measly pork, which contains the cysts in the meat, get pork tapeworm in their intestine,” says Hajek, who’s currently working on a volunteer basis at a hospital in Gulu, Uganda. “The pork tapeworm lives asymptomatically in our intestines and doesn’t bother us. But we can spread the eggs from the tapeworm in our stool, contaminate food, and infect others, including people and pigs.
“People and pigs who eat the eggs that may have contaminated their food get cysts, which can occur throughout the body, especially in muscles and brain,” he explains. “These cysts are surprisingly usually asymptomatic, and hide away from the immune system. They usually grow slowly to about one centimetre, the size of a marble, and then they die after a few years, and the person may never know they were infected.”
Because the infection is often asymptomatic and needs a brain scan like a CT or MRI to diagnose it, the true prevalence isn’t known, particularly in developing nations, Hajek says. However, studies suggest that in lower income countries with limited sanitation and inadequate separation of human waste from environments where pigs roam, about 30 percent of people with seizure disorder have NCC. Other research in endemic countries has shown that about two to 10 per cent of otherwise healthy adults have evidence of prior pork tapeworm infection.
Although rare, other cases have been reported in North America.
The CMAJ reported a case of a 51-year-old man who was diagnosed in 2009 with NCC after returning to Canada from a trip to Mexico. A farmer, he was originally from Mexico and had worked with pigs but had lived in Canada for several years. He sought medical attention after having a seizure.
He didn’t have any other symptoms. One of his lesions was surgically removed and he was treated successfully with medication.
In 2015, a California man had a live tapeworm removed from his brain during emergency surgery after he went to hospital for what he called the worst headache of his life.
A scan showed that the parasite in Luis Ortiz’s brain was cutting off circulation and water flow to the rest of his brain, the BBC reported.
Hajek, who’s vegan, says that although the risk is low even among meat-eaters, he’s still cautious about what he eats.
“I can’t say I worry about getting NCC while here in Uganda,” he says. “It could happen, but even with the number of pigs around and the less than perfect sanitation systems, it is very unlikely that I will get infected and sick as a result of NCC.”
“That said, I do generally try to be careful with what I eat, and try to eat foods that have been cleanly prepared by people who had washed their hands,” he continues. “Cooked food is safest.”
Hajek says that improving sanitation worldwide can help break the cycle and eliminate the disease.
“Canadians don’t generally have to worry about getting NCC at home,” Hajek says. “The rates of cysticercosis in pigs in Canada is probably zero or close to zero, and if you cook meat from pigs you kill the cysts and won’t get intestinal tapeworm or spread the infection.
“Although it is possible that someone can immigrate from an endemic country, be completely asymptomatic but have intestinal pork tapeworm, and shed eggs in their stool without knowing, this risk is low,” he adds. “And it’s even lower that their hygiene and food preparation practices are so low that they would contaminate food that you will eat. Perhaps it’s a good reminder of why we are careful with hygiene and sanitation.”