Trichinosis is a type of roundworm infection caused by the Trichinella parasite. The infection begins in the intestinal tract and then spreads to the body’s skeletal muscle tissue. While it is no longer common in the United States, trichinosis still occurs frequently in rural areas around the world. The most recent major outbreak of trichinosis occurred in Poland in 2007, when over 200 people fell ill.
Here are some of the most commonly asked questions about the diagnosis, treatment, and prevention of trichinosis:
1. How is trichinosis spread?
Trichinosis infection occurs when a person or animal ingests Trichinella larvae. The most common source of infection is raw or undercooked meat, particularly pork and non-commercial meat like bear and wild boar.
2. What are the symptoms of trichinosis?
Mild cases of trichinosis will often not present with any symptoms. Moderate or heavy infections can cause abdominal pain, diarrhea, fatigue, and nausea in the early stages; these symptoms then progress to include fever, muscle pain and tenderness, headache, sensitivity to light, swelling of the eyelids or face, and conjunctivitis (pink eye). Some people who experience these more serious symptoms will also develop complications like inflammation of the heart muscle, cough and shortness of breath, confusion and delirium, seizures, or bleeding in the lungs. While these more severe complications are extremely rare, they can linger for years without proper treatment. If you develop any of these symptoms after consuming pork products or any type of non-commercial meat, consult your doctor.
3. How is trichinosis diagnosed?
? Initial diagnosis of trichinosis relies on the classic symptoms, specifically conjunctivitis, swollen eyelids, and fever. If a patient presents with any of these symptoms after ingesting potentially infected meat, a doctor will then take a blood sample and run one of several simple tests to detect either an increase in certain white blood cells (eosinophils) or the presence of anti-Trichinella antibodies. Sometimes a muscle biopsy will also be conducted in order to look for Trichinella larvae.
4. How is trichinosis treated?
Many cases of trichinosis do not require any kind of treatment and will resolve on their own within a few months. For heavier infections, your doctor will prescribe one of a number of medications to address lingering symptoms like fatigue, headaches, and diarrhea. These include anti-parasitic medications, pain relievers, and corticosteroids.
5. How can I prevent trichinosis infection?
The only way to make sure you do not develop trichinosis is to follow proper meat handling and cooking procedures. Never eat undercooked meat. Whole cuts of meat other than poultry and wild game should be cooked to an internal temperature of 145 F; ground pork and beef should be cooked to at least 160 F. Whole cuts of poultry and ground poultry need to be cooked to at least 165 F, and wild game should be cooked to at least 160 F for both whole and ground varieties. If you eat wild meat, it is also a good idea to deep-freeze the meat for at least three weeks before consuming; this will kill the Trichinella parasite in most meats (although freezing does not affect the parasite in bear meat). And always wash your hands thoroughly after handling raw meat and meat products.
To prevent trichinosis infection in animals, don’t allow livestock (specifically pigs) to eat undercooked meat, scraps, or animal carcasses that may be infected with Trichinella larvae.
6. What are the different types of blood tests for trichinosis?
Blood samples are tested for trichinosis using several methods. The first is laboratory testing that looks for the elevated presence of certain white blood cells (eosinophils) and enzymes (creatine kinase, and lactate dehydrogenase). The second method looks for antibodies developed in response to Trichinella infection; these tests include indirect immunofluorescence tests, latex agglutination tests, enzyme-linked immunosorbent assays (ELISA) like the New Life Trichinella Microwell Serum ELISA. Each of these types of test has its own pros and cons, and doctors will often combine testing methods to ensure a definitive diagnosis.
Davis, Charles Patrick. 2016. “Trichinosis (Trichellosis)”. Available at http://www.medicinenet.com/trichinosis/article.htm.
Mayo Clinic. “Diseases and Conditions: Trichinosis.” Available at http://www.mayoclinic.org/diseases-conditions/trichinosis/basics/definition/con-20027095.