The larvae invade striated muscle cells of biceps, extraocular muscles and even diaphragm and myocardium.
- Infection from pork with encysted trichinella larvae
- Digestive action liberates the larvae
- T spiralis and T pseudospiralis
- Larvae invade small bowel mucosa
- 1st week: diarrhoea, abdominal pain, nausea, vomiting, constipation
- 2nd week: muscle invasion with fever raised eosinophils, facial and periorbital oedema, conjunctiva haemorrhage, myocarditis, heart failure, arrhythmias and potentially fatal
- 3rd week: muscle pain and swelling and weakness. Extraocular muscles, biceps, masseter, lower back, diaphragm, focal neurology from vascular occlusion
- FBC: Eosinophils ++ at 2-6 weeks
- Muscle biopsy shows larvae and as they calcify can be seen on X-ray but not useful in acute infection
- Positive serology
- Raised CK and LDH and myoglobinuria
- CT scan: small hypodensities in the cortex and white matter
- Abnormal ECG due to myocardial involvement including STEMI
- Albendazole 400 mg BD for 10-14 days
- Steroids to reduce myositis and myocarditis and any Jarisch-Herxheimer like reactions. The use of steroids is controversial.
- Adequate cooking of all meat products will prevent infection with the Trichinella species.