A tapeworm is a long, ribbon-like flatworm known to cause parasitic infections in animals and humans. According to MayoClinic.com, the most common tapeworms associated with human infection are the pork tapeworm, beef tapeworm, dwarf tapeworm and fish tapeworm. Both tapeworm eggs and larvae can cause infection in humans. Worm larvae will adhere to the intestinal wall, where they will develop into adult tapeworms. Certain tapeworm eggs, however, can travel outside of the intestines, infecting other areas of the body such as the brain. There are several causes of tapeworm infection, all of which can be prevented.
Raw or Undercooked Meats
Humans can contract tapeworms by eating raw or undercooked meats. Animals such as cows or pigs infected with tapeworms will have larvae in their muscle tissue. If properly cooked, the meat from these animals is safe for human consumption. However, if the meat is raw or undercooked, the larvae will remain alive after being ingested and will continue to grow to adulthood within the intestines. Additionally, pork larvae can migrate out of the intestines to infect other areas of the body such as the liver, lungs and brain.
Undercooked Fish and Sushi
Consuming undercooked or raw fish in the form of sushi can lead to tapeworm infection. According to the Seafood Network Information Center, freshwater fish, like trout, or fish that spend part of their life in freshwater, such as wild salmon, may carry tapeworm larvae. Because of this, freshwater fish should never be used to make sushi and should always be properly cooked before eating.
Contaminated Soil and Water
Tapeworm infection can also be caused by soil and water contaminated with tapeworm eggs. Soil and water become contaminated when an animal passes tapeworm eggs in its stool. Food sources that come in contact with contaminated water or soil can then become contaminated as well. Contamination via soil and water is common in developing countries with poor sanitation and greater human exposure to livestock.
Poor Hygiene
According to The Merck Manuals Online Medical Library, humans who ingest pork tapeworm eggs can become immediate hosts. Tapeworm infection can be caused by contact with contaminated stool from these human hosts. Additionally, immediate hosts may transfer tapeworm eggs to others if the eggs are ingested after contact with the host, through food handling or via contaminated clothing or furniture. Human hosts can avoid infecting others by simply following proper hygiene and hand washing techniques.
Considerations
While most intestinal tapeworm infections usually cause only mild symptoms such as abdominal discomfort, diarrhea and loss of appetite, infections involving other areas of the body can lead to serious complications such as seizures, blindness or paralysis. Because of this, it is important to avoid known causes of tapeworm infection and seek medical attention immediately should you suspect you have become infected. According to Medline Plus, most people realize they are infected when they notice pieces of the worms in their stool.
