Trichinella

Don’t confuse Trichinella with Trichuris trichiura - their clinical presentations are very different.

Trichinella spiralis is a nematode that infects humans after you eat raw or undercooked meat (especially pork and wild game). The infectious form in meat is the cyst, which contains encysted larvae.

After you ingest cyst-containing meat:

• Gastric acid and pepsin release the larvae from the cysts.
• The larvae invade the small-intestinal mucosa and mature into adult worms.
• New larvae are produced, then migrate through the body and encyst in striated muscle.

Clinical presentation typically occurs in two phases:

• Early (intestinal) phase: nausea, diarrhea, vomiting, and abdominal pain.
• Later (systemic/muscle) phase (weeks later): fever, muscle pain, classic periorbital edema, headache, itching, cough, diarrhea, or constipation.

In severe infestations, complications may include congestive heart failure due to myocarditis, encephalitis, pneumonitis, hypokalaemia, adrenal gland insufficiency, and death.

Diagnosis is made with ELISA and immunoblot for antibody detection. A muscle biopsy will show encysted larvae.