Symptoms

Signs and symptoms of trichinosis infection and their severity vary depending on the number of larvae consumed in the infected meat. Abdominal symptoms can occur one to two days after infection. Other symptoms usually start two to eight weeks after infection.

Possibly no signs or symptoms

Mild cases of trichinosis — those with only a small number of parasites in your body — may cause no recognizable signs or symptoms. Symptoms can develop with moderate or heavy infestation, sometimes progressing as the parasite travels through your body.

Initial signs and symptoms

You swallow trichinella larvae encased in a cyst. Your digestive juices dissolve the cyst, releasing the parasite into your body. The larvae then penetrate the wall of the small intestine, where they mature into adult worms and mate. At this stage, you may experience:

• Diarrhea
• Abdominal pain
• Fatigue
• Nausea and vomiting

Later signs and symptoms

About a week after infection, the adult female worms produce larvae that go through the intestinal wall, enter your bloodstream, and eventually burrow into muscle or other tissue. This tissue invasion can cause:

• High fever
• Muscle pain and tenderness
• Swelling of the eyelids or face
• Weakness
• Headache
• Sensitivity to light
• Pink eye (conjunctivitis)

When to see a doctor

If you have a mild case of trichinosis with no symptoms, you might not need medical attention. If you experience gastrointestinal problems or muscle pain and swelling about a week after eating pork or wild-animal meat, talk to your doctor.