Your health care provider can diagnose trichinosis by discussing your symptoms and doing a physical exam. You provider may also ask if you've eaten raw or undercooked meat.
To diagnose your infection, your health care provider might use these tests:
- Blood tests. Your provider may take a blood sample and test it for signs suggesting trichinosis. These signs include an increase in the number of a type of white blood cell (eosinophils) or the formation of antibodies against the parasite after several weeks.
- Muscle biopsy. A blood test typically is enough to make a diagnosis. But your provider might also recommend a muscle biopsy. A small piece of muscle is removed and examined under a microscope to look for roundworm (trichinella) larvae.
Trichinella larvae travel from the small intestine through your bloodstream to bury themselves inside muscle tissue. Because of this, stool sample tests don't often show the parasite.
Trichinosis usually gets better on its own. In cases with a mild or moderate number of larvae, most signs and symptoms typically go away within a few months. However, fatigue, mild pain, weakness and diarrhea may stay for many months or years. Infection with a large number of larvae can cause more-severe symptoms that need treatment right away.
Your health care provider may prescribe medications depending on your symptoms and the severity of infection.
Anti-parasitic medication. Anti-parasitic medication is the first line of treatment for trichinosis. If your provider discovers that you have roundworm (trichinella) parasites early, albendazole (Albenza) or mebendazole (Emverm) can kill the worms and larvae in the small intestine. The drugs may cause nausea, vomiting, diarrhea and stomach pain during the treatment.
If your provider discovers the infection after the larvae bury themselves in muscle tissues, the anti-parasitic drugs may not kill all the parasites. However, your provider might prescribe one if you have brain, heart or lung problems due to larvae causing pain and swelling (inflammation) in these organs.
- Pain relievers. After the larvae have entered the muscles, your provider may prescribe pain relievers to help relieve muscle aches and pain and swelling (inflammation). Over time, the larvae cysts in your muscles tend to harden into calcium (calcify). As a result, the larvae die, and the muscle aches and weakness usually go away.
- Steroid medication. Sometimes trichinosis can cause an allergic reaction. This happens when the parasite enters muscle tissue or when dead or dying larvae release chemicals in your muscle tissue. Your provider might prescribe a steroid medication to control pain and swelling.
Preparing for your appointment
You're likely to start by seeing your family health care provider. In some cases, you may be referred to an infectious disease specialist.
Here's some information to help you get ready for your appointment.
What you can do
- Be aware of pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as limit your diet.
- Make a list of your symptoms, including any that seem unrelated to the reason for which you scheduled the appointment.
- Make a list of key personal information, including major stresses or recent life changes. Also let your provider know if you've eaten any raw or rare pork or wild-animal meat lately.
- List all medications, vitamins, herbs and supplements you take.
- Take a family member or friend along, if possible. Someone who goes with you can help you remember the information you get.
- Make a list of questions to ask your health care provider.
For trichinosis, some questions to ask include:
- What is likely causing my symptoms or condition?
- What are other possible causes?
- What tests do I need?
- Is my condition likely temporary or chronic?
- What's the best course of action?
- What are the alternatives to the primary approach you're suggesting?
- I have other health conditions. How can I manage them together?
- Is there a generic alternative to the medicine you're prescribing?
- Are there brochures or other printed material I can take? What websites do you recommend?
Don't hesitate to ask other questions during your appointment.
What to expect from your doctor
Your health care provider is likely to ask you a number of questions, including:
- When did your symptoms begin?
- Have you eaten raw or rare pork or wild-animal meat lately?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, improves your symptoms?
- What, if anything, worsens your symptoms?
Preparing for your appointment will help you make the most of your time with your health care provider.
May 25, 2022
- AskMayoExpert. Roundworm infection. Mayo Clinic; 2021.
- AskMayoExpert. Myopathy and myositis (adult). Mayo Clinic; 2021.
- Trichinellosis (also known as trichinosis). Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/trichinellosis/index.html. Accessed March 4, 2022.
- Resources for health professionals: Trichinellosis (also known as trichinosis). Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/trichinellosis/health_professionals/index.html. Accessed March 4, 2022.
- Trichinosis. Merck Manual Professional Version. https://www.merckmanuals.com/professional/infectious-diseases/nematodes-roundworms/trichinosis. Accessed March 4, 2022.
- Foreyt WJ, et al. Trichinosis: U.S. Geological Survey Circular 1388. U.S. Department of the Interior. 2013; doi:10.3133/cir1388.
- Weller PF, et al. Trichinellosis. https://www.uptodate.com/contents/search. Accessed March 4, 2022.
- Parasites and foodborne illnesses. U.S. Department of Agriculture. https://www.fsis.usda.gov/food-safety/foodborne-illness-and-disease/pathogens/parasites-and-foodborne-illness#6. Accessed March 4, 2022.
- Mebendazole oral. Facts & Comparisons eAnswers. https://fco.factsandcomparisons.com. Accessed March 8, 2022.
- Abendazole oral. Facts & Comparisons eAnswers. https://fco.factsandcomparisons.com. Accessed March 8, 2022.
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