Clinical Features:
Light infections may be asymptomatic.  Intestinal invasion can be accompanied by gastrointestinal symptoms (diarrhea, abdominal pain, vomiting).  Larval migration into muscle tissues (one week after infection) can cause periorbital and facial edema, conjunctivitis, fever, myalgias, splinter hemorrhages, rashes, and blood eosinophilia.  Occasional life-threatening manifestations include myocarditis, central nervous system involvement, and pneumonitis.  Larval encystment in the muscles causes myalgia and weakness, followed by subsidence of symptoms.

Laboratory Diagnosis:
The suspicion of trichinellosis (trichinosis), based on clinical symptoms and eosinophilia, can be confirmed by specific diagnostic tests, including antibody detection, muscle biopsy, and microscopy.

Diagnostic findings

• Microscopy
• Antibody detection

Treatment:
Several safe and effective prescription drugs are available to treat trichinellosis.  Treatment should begin as soon as possible and the decision to treat is based upon symptoms, exposure to raw or undercooked meat, and laboratory test results.  Steroids are used for infections with severe symptoms, plus mebendazole*, with albendazole* as an alternative.  For additional information, see the recommendations in The Medical Letter (Drugs for Parasitic Infections).

* This drug is approved by the FDA, but considered investigational for this purpose.