Confirmed Case

Clinical illness [1] 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

Probable Case

Clinical illness^[1] 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

^[1]Clinical illness: Symptoms depend on the stage of the lifecycle. Systemic invasion by larvae result in fatigue, fever, myalgia/myositis, periorbital edema, sub-conjunctival and/or sub-retinal hemorrhages and eosinphilia. Adult worms in the intestine may rarely cause diarrhea, abdominal cramps and vomiting.

Outbreaks

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.