Background
- Acidic stomach medium dissolve infective Trichinella cysts to release larvae
- Larvae mature to adult in small intestine
- Adult females lay eggs that develop into larvae, travel through the vascular tree to muscle
- Within muscles, the larvae encyst
- Transmission of infection with ingestion of cysts
- Proper cooking kills the encysted larvae
Aetiology
- Trichinellosis is a parasitic disease caused by eating raw or undercooked meat of animals infected with the larvae of a type of worm called Trichinella
- Infection occurs commonly in certain wild carnivorous animals but can also occur in domestic pigs
- Trichinellosis is a very rare Ireland 9no cases had been reported prior to 2007)
- In June 2007, an outbreak of trichinellosis in Poland led to the identification of the illness in Ireland in people who had travelled to Poland
- Trichinellosis can vary from unnoticed mild condition to fatal infection
- In animals trichinellosis rarely presents as a clinical disease
- All pigs slaughtered for human consumption have to be tested and shown to be free from this worm
- No cases detected in Irish pigs for decades
- May be found in Irish foxes
Symptoms of trichinellosis?
- Incubation period 1 - 6 weeks after ingestion of infected meat
- The first symptoms can involve swelling of the eyes
- GI upset (diarrhoea, vomiting, and abdominal discomfort)
- Fatigue, fever headaches, shivering, cough, arthralgia & myalgia
- Later in-coordination, arrhythmia
Most symptoms subside within a few months. Mild cases of trichinellosis are never specifically diagnosed and are assumed to be the flu or other common illnesses.
Diagnosis
- Gastroenteritis & Myalgia
- Facial oedema, or sub-conjunctival haemorrhages
- Eosinophilia
- Dx confirmed with serology (occas. muscle Bx)
Differential Dx
- Influenza
- Typhoid
Treatment
- Anti parasitics (e.g. Mebendazole)
Prevention
- Cook meat products until the juices run clear
- Freezing pork less than 15cm thick for 20 days at -15°C will kill any larvae
- Freezing wild game meats is not guaranteed to kill all larvae
- Curing (salting), fermenting, pickling, drying, smoking, or microwaving meat does not consistently kill infective worms