What is Trichinosis

Trichinosis is a rare infection that is caused by a parasitic worm. People can become infected by eating raw or undercooked meat of an animal that is infected with this worm. The severity of the illness varies depending on the number of worms in the contaminated meat.

Trichinosis can range from mild to severe. In mild to moderate cases, most symptoms will go away in a few months. If the worms heavily invade the heart, the lungs, or the brain and spinal cord (nervous system), the infection can cause serious health problems.

What are the causes?

Trichinosis is caused by a type of parasitic worm called Trichinella spiralis. In infected meat, immature worms (larvae) are contained within small cysts. When a human eats infected meat, the stomach acid dissolves the cysts, releasing the larvae. The larvae then travel into the intestines where they can mature and lay eggs. Once the eggs hatch, the worms can travel through the arteries into muscles. When worms reach the muscles, a cyst forms around the worms.

What increases the risk?

You are more likely to develop this condition if you eat certain undercooked meats, including meats of the following animals: pig, wild boar, bear, wild feline (such as cougar), fox, horse, wolf, walrus, seal, or dog.

What are the signs or symptoms?

Early symptoms occur when the larvae are in the intestine. These symptoms usually occur 1–2 days after eating infected meat, and they may include:

• Diarrhea.
• Abdominal pain.
• Nausea and vomiting.
• Fatigue.
• Fever.

7–10 days after eating infected meat, you may also develop other symptoms, such as:

• Swelling of the face, especially around the eyes.
• Muscle aches and pain.
• Fatigue.
• Weakness.
• Headache.
• Fever.
• Chills.
• Shortness of breath.
• Coughing.
• Itchy skin.
• Diarrhea or constipation.
• Problems with coordination.

How is this diagnosed?

This condition may be diagnosed based on:

• Your medical history.
• Your symptoms.
• A physical exam.
• Blood tests.
• Testing a sample of muscle tissue under a microscope (biopsy).

How is this treated?

This condition is treated with medicines that kill any worms that are in your body (antiparasitics). The type of medicine you take and how long you take it depend on how severe your condition is. Your health care provider may also prescribe medicines to relieve swelling and pain (corticosteroids).

Follow these instructions at home:

• Rest as much as possible until you feel better. Return to your normal activities as told by your health care provider.
• Take over-the-counter and prescription medicines only as told by your health care provider. Do not stop taking your medicine even if you start to feel better.
• Drink enough fluid to keep your urine pale yellow.
• Eat a healthy diet. Eat small, frequent meals throughout the day while you are recovering.
• Keep all follow-up visits as told by your health care provider. This is important.

How is this prevented?

• Wash your hands with soap and warm water after handling raw meat to avoid spreading the infection.
• Do not eat meat that is raw or undercooked. Cooking meat properly will kill any worms in the meat. If possible, use a food thermometer. Different types of meat should be cooked to certain temperatures.
• Clean meat grinders thoroughly after use.
• Make sure to cook all wild game meat thoroughly, even if it was previously frozen. Freezing may not kill bacteria.
• Avoid eating homemade jerky or sausage that was only cured, dried, or smoked. These cooking techniques do not consistently kill bacteria.
• Freeze pork meat less than 6 inches thick for 20 days at 5°F or colder. This can kill any bacteria in the pork meat.
• Do not allow wild animals or pigs to eat undercooked meat or scraps. This will help prevent the bacteria from spreading.

Contact a health care provider if:

• Your symptoms get worse.
• You have pain that gets worse or does not get better with medicine.
• You have a fever.

Get help right away if:

• You develop a severe headache.
• You have a stiff or painful neck.
• You have chest pain.
• You have an irregular heartbeat.
• You have shortness of breath or trouble breathing.
• You have trouble coordinating movements.
• You experience dizziness or confusion.
• You have jerky movements that you cannot control (seizure).
• You have severe nausea and vomiting.

Summary

• Trichinosis is a rare infection that is caused by a parasitic worm.
• People can develop this infection by eating raw or undercooked meat of an animal that is infected with this worm.
• The most common sources of this infection include undercooked pig, bear, and wild boar meat.
• Early symptoms include abdominal pain, vomiting, diarrhea, fatigue, and fever. Later symptoms can also include headache, muscle weakness, itchy skin, shortness of breath, and problems with coordination.
• This condition is treated with medicines that kill any worms that are in your body (antiparasitics). The type of medicine you take and how long you take it depend on how severe your condition is.