Clinical illness  with laboratory confirmation of infection:
- Positive serologic test for Trichinella sp. OR
- If a muscle biopsy is conducted, such as during autopsy, demonstration of Trichinella sp. encysted larvae or larvae in tissue by microscopy or nucleic acid amplification
Clinical illness in a person who:
- is epidemiologically linked to a confirmed case OR
- has consumed food (meat) which had demonstration of Trichinella sp. encysted larvae or larvae
Clinical illness: Symptoms depend on the stage of the lifecycle. Systemic invasion by larvae result in fatigue, fever, myalgia/myositis, periorbial edema, sub-conjunctival and/or sub-retinal hemorrages and eosinphilia. Adult worms in the intestine may rarely cause diarrhea, abdominal cramps and vomiting.
In an outbreak, at least one case must be laboratory confirmed. Associated cases should be reported as confirmed if the patient shared an epidemiologically implicated meal or ate an epidemiologically implicated meat product and has either a positive serology for trichinosis or a clinically compatible illness.