Some solitary cousins
Taenia solium and its cousin Taenia saginata are best known as tapeworms. They are segmented flat worms that live in our intestines, feeding off what we eat and can be several meters long. They have an intermediary host1, pork for Taenia solium and beef for Taenia saginata, and a definitive host2, humans.
Taenia solium is found as larval cysts in pigs’ muscles and we ingest it by eating insufficiently cooked meat. To avoid that, always cook pork meat all the way to the center and do not eat raw bacon!
Tapeworms are parasites3 and usually go unnoticed. Sometimes they can cause abdominal pain, nausea and weight loss. Unlike other intestinal worms such as pinworms4 and roundworms5, tapeworms are not eliminated with classical deworming treatments. You need to use specific anti-parasitic drugs to get rid of them.
Pig farming under surveillance
Taenia solium is rare in Europe because hog farming is under tight surveillance by veterinary services. It is more frequent in some developing countries, especially when humans live closely to pigs and have poor hygiene. Contamination occurs through eggs in pig poop. Occasionally, Taenia solium larvae can colonize the brain or eye, causing a serious disease called cysticercosis6.
And in fish ?
In the samples analyzed by the University Hospital of Lausanne, we can frequently find a third flat worm, Diphyllobothrium latum. It is found in fish and is transmitted to humans through the consumption of raw or undercooked products such as sushi or salmon tartars
Intermediate host1 = Host of a parasite within which the parasite goes from a developmental stage to another.
Definitive host2 = Host of a parasite where it matures and reproduces.
Parasite3 = Animal or plant organism which cannot survive without its host.
Pinworms4 = Small white intestinal worms, a few centimeters big. They are quite frequent in children and their surroundings. In the evening and at night, the female lays its eggs around the anus, producing an irritating substance. Scratching of the area will lead to dissemination of the eggs. Pinworms are not dangerous and easily treatable.
Roundworms5 = Intestinal worms that can cause bloating and abdominal pain. They look like earthworms, which explains their name vermicoid ascaris.
Cysticercosis6= Disease caused by larval cysts of the tapeworm Taenia solium found in pigs. The disease is benign when the larvae end up in the muscles or subcutaneous tissues. However, serious complications can occur when the larvae infect the eye or brain (seizures).