A man from China with “a history of eating raw beef” became the home of a 6-meter-long (20-foot-long) tapeworm, according to a case report recently published online in The New England Journal of Medicine.

After two years of stomach aches, lack of appetite and chronic anemia, the man's symptoms suddenly worsened with severe abdominal pain, vomiting, weakness and rapid weight loss. The worsening of his health forced him to go to the doctors, where they quickly referred him to the Department of Infectious Diseases at Renmin Hospital in Shiyan, China.

Although a physical examination showed nothing too unexpected, they did find an oncosphere – the larval form of a tapeworm – in his poop sample.

The doctors gave the man praziquantel and mannitol, an antiparasitic drug and cathartic drug, respectively. This combination first paralyzes the worm and then "flushes" it out of the body by speeding up defecation.

The guilty tapeworm. Credit: The New England Journal of Medicine

Based on an examination of the worm and, of course, his penchant for eating raw beef, the doctors diagnosed the man with a beef tapeworm (Taenia saginata) infection. Tapeworms enter the body as eggs or larvae onboard contaminated food, in particular raw or undercooked meat, where they travel down to the small intestine and attach themselves to its wall. They can live there for years, often causing no more than a sense of fullness and nausea.

Jian Li, one of the doctors who diagnosed the man, told Live Science that tapeworms are actually pretty rare in central China where this case was reported. While the northwest and southwest districts of China have a high rate of tapeworm infection, there haven’t been any reports of tapeworms in central China for 30 years. Tapeworms are rare throughout the United States and Europe, with infection rates much higher in developing countries.

Three months later, the man was reportedly back to full health and had regained his appetite for food – hopefully that doesn’t include raw beef anymore.