On Monday, a North Korean soldier defected to South Korea, pulling off a daring escape from the reclusive, authoritarian nation, and successfully crossing the demilitarized zone between the two countries. During the escape, he was shot several times by guards from his own country; when rushed to the hospital, surgeons discovered fresh horrors lurking in his intestines: parasitic worms.
South Korean doctors told journalists on Monday that the patient was stable, but that his insides contained “an enormous number” of worms, the longest of which was 11 inches long. “In my over-20-year-long career as a surgeon, I have only seen something like this in a textbook,” Dr. Lee Cook-jong, a doctor who treated the defector, told The Guardian.
Details on the case are still pretty scant, but two parasitologists told The Daily Beast that the worms are most likely roundworms, an extremely common parasite found in impoverished and developing countries that is usually spread when food sources are contaminated by human feces.
“I think it’s probably a roundworm,” Paul Crosbie, a parasitologist at California State University, Fresno, told The Daily Beast in an interview. “But we’re dealing with some really iffy information here.” (Disclaimer: Crosbie is the author’s father.)
Crosbie said that his best guess is the worms are a species of roundworm in the ascaris genus, which are some of the most common intestinal worms. Crosbie said the largest female ascarids usually grow to about 9 inches, which would make Lee’s surprise make sense, although members of the genus have been recorded as long as 14 inches.
There are other kinds of common worms that live inside humans, of course. Crosbie mentioned whipworms, which “sew themselves” into the lining of the large intestine and often cause bleeding. Considering the volume and size of the worms, however, Crosbie said it’s unlikely they were in the large intestine, which measures only a couple feet long. Roundworms and tapeworms aren’t embedded in the inner lining as much, and would be easier to notice during a more intense surgical operation, like treating gunshot wounds in the abdomen.
But tapeworms can often grow to “many, many feet” long, which makes them less likely to be remarkable at only 11 inches. According to Crosbie, that makes a roundworm the most plausible parasite the defector was housing in his intestines.
Roundworms like ascarids spread through direct transmission, usually through food contaminated with human feces. Humans infected with the parasite spread its eggs in their poop, which then infect other hosts who eat food contaminated with the fecal matter. Fecal contamination is widespread in impoverished and developing countries, as farmers there often use human excrement as fertilizer to grow crops in otherwise nutrient-deprived environments.
“Chemical fertiliser was supplied by the state until the 1970s, but from the early 1980s, production started to decrease,” Lee Min-bok, a North Korean agriculture expert, told The Guardian. “By the 1990s, the state could not supply it any more, so farmers started to use a lot of night soil instead.”
And Crosbie said the soldier isn’t alone—the number of people routinely infected with roundworms is astonishing.
“The general estimates for how many people have big roundworms [ascarids and other related species like whipworms] in impoverished countries worldwide... we’re talking up to 1.5 billion people harboring these parasites.”
Dr. Thomas Nutman, the head of the National Institute of Health’s laboratory of parasitic diseases, agreed, putting the number of infected people worldwide at between 1 and 1.5 billion, although exact data is hard to come by. In particularly stricken communities, the infection rate can approach 40 to 50 percent of the population, with individuals in their late teens most likely to be infected.
“Although we do not have solid figures showing health conditions of North Korea, medical experts assume that parasite infection problems and serious health issues have been prevalent in the country,” professor Choi Min-ho of Seoul National University’s College of Medicine told The Guardian, noting that the man’s condition was “not surprising at all considering the North’s hygiene and parasite problems.”
Ascarids flourish in warm or tropical climates, throughout South and Central America, Africa, the Indian subcontinent, and Southeast Asia. While ascarids can cause discomfort, most of the time their host doesn’t even realize they’re there.
“Even with huge numbers of worms, the patients are clinically asymptomatic,” Nutman told The Daily Beast in an interview.
The worms are just a fact of life in countries struggling with poverty and malnourishment. “In reality, most people live with their worms,” Crosbie said.
But Crosbie said there’s a good chance a South Korean doctor would have never seen common roundworms—in the developed world, we’ve almost completely wiped them out. Developed countries with rigorous food safety standards have almost entirely shut down ascarid’s “infection vector”—the fecal contamination they need to continue their parasitic lifestyle, meaning doctors usually wouldn’t come across them in everyday practice.
Tapeworms, on the other hand, need a secondary host—usually an animal like a cow or a pig—before infecting humans.
“The classic human tapeworms we get by eating infected beef and pork, which wouldn’t seem to be the case because these people are impoverished and aren’t getting to eat a bunch of meat,” Crosbie said. (The Guardian also notes that doctors found large amounts of corn in the patient’s stomach.)
Doctors told BBC they were paying close attention to the parasites to prevent them from complicating the man’s serious gunshot wounds.
“You can imagine—these are living things, and they live in the lumen of the GI tract,” Nutman said. “If this patient had surgery on GI tract and these things were flailing about, let’s just say it’s possible that they could have a deleterious effect on the sutures.”
Assuming the young soldier pulls through, treatment is relatively simple—another reason the parasites are almost completely extinct in developed countries.
“Both roundworms and tapeworms are easily treated with longstanding anti-worm drugs,” Crosbie said. “You take the drug, and it either kills the parasite or makes it let go of its grip in the intestine and you shit them out.”
In the defector’s case, this time, they won’t make it back into the food supply.