A Singaporean man had no idea he’d been a victim of a parasitic infection. He’d suffered no symptoms at all, until one day he passed a huge tapeworm.
At over 9 feet, the worm was about one-and-a-half times longer than the man. Doctors had to bend it 18 times to fit it into a picture.
“The patient was somewhat appalled when the worm was passed out via the rectum,” said infectious diseases expert Hsu Li Yang of Singapore General Hospital, The Straits Times reported.
The case dates back to 2016, but was only recently publicized after The Straits Times asked the hospital for local examples of parasitic infections.
Tapeworm infections are typically caused by eating raw or under-cooked meat. This particular worm’s eggs most resembled those of a fish tapeworm, the hospital’s Department of Microbiology concluded.
Most tapeworms have a two-stage lifecycle that is split between two hosts. In many cases, the lifecycle involves the eggs first entering a primary host—a cow, pig, fish, or even human. The eggs hatch into larvae and migrate into the host’s muscles, where they can form cysts. Some tapeworms can also form a cyst in the brain, which can be very dangerous for the host.
The second stage comes when the primary host—cow, pig, or fish—is killed and eaten raw or under-cooked by humans. The larvae then lodges in the intestines and develops into an adult tapeworm. The worm attaches its head to the intestine and consumes nutrients from the host, growing successive segments to its body that can reach lengths of of 50 feet. Each of the segments contains thousands of eggs, which the secondary host excretes. The eggs get into sewage and can eventually end up in water bodies and the environment in general, thus completing the cycle.
Improving sewage treatment has been reducing tapeworm infections in the developing world, as it breaks the tapeworm life cycle. But there’s been an increase of tapeworm infections in the developed word due to increased popularity of eating raw fish, a 2012 Can Fam Physician article stated.
Some infected people may experience abdominal pain, diarrhea, upset stomach, loss of appetite, and weight loss. Others suffer no symptoms. One can avoid infection by eating only properly prepared meat.