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Does eating undercooked meat put you at risk for tapeworms?

Raymond Lepage, PhD, Doctor in Biochemistry
Raymond Lepage, PhD, Doctor in Biochemistry
Science popularizer

Barbecue season is when people are more likely to eat contaminated meat because it is undercooked. Although strict hygiene standards reduce the risk of food contamination in Canada, eating undercooked meat still poses various risks of infection. Among these, it is possible to ingest one tapeworm species, which can develop in the intestine with few or no symptoms and reach up to 10 metres in length.

What is a tapeworm?

As its name suggests, it is a worm from the taenia family (or tapeworms). It usually develops for years in the intestine by taking advantage of the food ingested by the human host and can reach eight to ten metres in length. It causes a parasitosis or parasitic disease with minimal symptoms, thus hindering early detection.

How do you get infected with a tapeworm?

Infection usually occurs from ingesting raw or undercooked meat or fish that was contaminated beforehand. Pigs or cattle are so-called "intermediate" hosts that carry tapeworm eggs in their muscles or organs and transmit them to humans, who become "definitive" hosts.

There are several different tapeworms that vary depending on the meat consumed. Risk levels also vary among tapeworm families. Intestinal tapeworms are generally from the following:

  • Beef (taenia saginata or internal tapeworm)
  • Pork (taenia solium or pork tapeworm)
  • Some raw fish (Diphyllobothrium latum)
  • Some insects, such as beetles and especially in hot countries (Hymenolepis nana) [1]
Cysticercosis – a serious disease caused by the pork tapeworm

Cysticercosis or taeniasis is a tissue infection that is rare in Canada. It affects the brain, muscles or other tissues and can cause seizures. Cysts in the brain can cause a variety of conditions such as headaches or seizures and, in some rare cases, may even be life-threatening.

It is possible to contract cysticercosis by absorbing tapeworm eggs from the feces of an infected person. The likelihood of such an infection is greater in places with poor hygiene and close contact between humans and free-roaming pigs. It can also occur when someone infected with Taenia solium fails to wash their hands and then prepares food for a group of people. [2]

How do you recognize and treat a tapeworm infection?

Symptoms of this type of parasitosis are generally unremarkable. Infected people are often asymptomatic, which means this disease is often underdiagnosed.

There are no accurate Canadian figures for this type of infection, and it would probably be less than 1,000 in the United States, although there are no precise counts of this disease there either. [3]

On the other hand, in France, cases of taenia saginata (linked to beef) amount to about 500,000 per year. Other taenias are quite rare, thanks to the numerous veterinary controls on pig farms.

Know how to spot the symptoms

The two most obvious symptoms to look for are the following:

  • Weight loss not linked to a decrease in appetite or food intake
  • The presence of rings (white filaments) in your feces

However, since the worm takes years to reach its adult size (it can live up to 30 years in its host), these symptoms are not always readily apparent.

In some cases, other symptoms may appear earlier, such as the following:

  • Nausea
  • Loss of appetite
  • Abdominal pain
  • Diarrhea
  • Dizziness
  • Salt craving
  • Weakness [4]

When in doubt, it is strongly recommended to consult your doctor or go to a laboratory to perform microscopic analysis of the stool and obtain a reliable diagnosis. It is the only test to determine whether eggs are in the feces.

Effective treatments to eliminate tapeworms

As with our dogs and cats, simply taking a worm control product is the most effective way to remove this unwanted guest from the intestines permanently. Once killed by the medication, the tapeworm will be evacuated naturally through the stool. A cleansing agent may be prescribed to facilitate this operation. 

If adequately treated, the infection will clear up in most cases. [5]

Prevention is the best cure

The risk of tapeworm infection is relatively low in Quebec but not nonexistent. Keep in mind that carpaccios, tartars and other sushi dishes increase the risk of parasitosis or infections.

It is also advisable to avoid buying any ground meat and opt for whole pieces of meat. Frozen fish is also recommended as the freezing process destroys parasites.

Here are some basic hygiene tips that can also limit the risks:

  • Wash your hands after using the bathroom
  • Wash your hands before and after handling food
  • Wash fruits and vegetables (there may be surface bacteria)
  • De-worm your pets regularly

Finally, remember that cooking meat adequately in the middle (at least 71°C) is the best way to kill any potential parasites. [6] So be sure to leave your meat and fish on the grill for an extra two or three minutes this summer. Healthy tastes better.

For professional support, we’re here for you.

We provide services that can help your doctor diagnose tapeworms and related health problems and determine the appropriate treatment.

Do you have a medical prescription for this test? Book an  appointment online or contact Biron Health Group’s customer service at  1 833 590-2712.

Sources6
  1. Laty, D. (January 7, 2021). “Tapeworms: How do you get infected? What should you do?” (freely translated). Santé Magazine. https://www.santemagazine.fr/sante/fiche-maladie/ver-solitaire-876423#:~:text=Le%20ver%20solitaire%20est%20une,est%20hermaphrodite%2C%20plat%20et%20segment%C3%A9
  2. Centers for Disease Control and Prevention. (September 22, 2020). Parasites – Cysticercosis. CDC. https://www.cdc.gov/parasites/cysticercosis/index.html
  3. Centers for Disease Control and Prevention. (September 22, 2020). Parasites – Taeniasis. CDC. https://www.cdc.gov/parasites/taeniasis/gen_info/faqs.html
  4. Mayo Clinic. (March 16, 2021). Tapeworm infection. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/tapeworm/symptoms-causes/syc-20378174
  5. Rossant-Lumroso, J., and Rossant L. (December 18, 2019). Tapeworms: Symptoms and treatments (freely translated). Doctissimo. https://www.doctissimo.fr/html/sante/encyclopedie/sa_1182_vers_intestin05.htm
  6. Government of Canada. (May 25, 2020). Cooking temperatures chart. https://www.canada.ca/en/health-canada/services/general-food-safety-tips/safe-internal-cooking-temperatures.html
Raymond Lepage, PhD, Doctor in Biochemistry
Raymond Lepage, PhD, Doctor in Biochemistry
Science popularizer