|
TRICHINOSIS FACT SHEET
Date of publication: October 2001
This fact sheet provides information and recommendations on managing the risks associated with trichinosis, the human disease caused by infection with the parasite Trichinella spiralis. In September 2001 two human cases of trichinosis occurred in the Coromandel as a result of eating homekilled pigs. Trichinosis is a preventable disease. This fact sheet describes simple recommendations that if followed will prevent spread amongst feral pigs and from feral to domestic pigs, and prevent human infection from eating infected meat derived from homekilled or recreational catch pigs.
The first symptoms of the disease in humans are high fever, nausea, diarrhoea, vomiting and abdominal discomfort. Headaches, fever, chills, cough, aversion to bright light, swollen or puffy eyes, aching muscles and sometimes an itchy rash or skin irritation may follow. Symptoms may be mild and flu-like or severe, and can occur from 1-2 days and up to 8 weeks after eating poorly cooked, contaminated meat. If you think you may be suffering from trichinosis, see your General Practitioner or health provider. Be sure to mention if you have prepared or eaten homekill or wild pig meat.
Life cycle of Trichinella spiralis
Trichinella spiralis is a nematode worm that is passed between carnivores as a result of eating larvae inside muscle tissues.
The parasite normally cycles in rodents (rats and mice). Infection in cats and pigs will result if they eat infected mice. If humans then eat infected pig meat, the larvae mature into worms in the small intestine and release eggs and larvae into the blood.
The larvae travel from the blood into muscle tissues. This causes the symptoms of trichinosis, fever and muscle pain. Animals can become a source of infection for other animals when larvae inside the muscle is eaten.
Infections in domestic pigs and humans are thought to be rare events in New Zealand.
The level and distribution of infection in wildlife reservoirs (rodents, mice, feral pigs) has been investigated in relation to previous outbreaks, but comprehensive studies have not been undertaken. |  |
For further information contact:
MAF Emergency Disease and Pest Hotline: 0800-809-966
Health Waikato Public Health Unit: 07-838-2569
New Zealand Pork Industry Board: 04-385-4229 | Source of figure: Website of the Centres for Disease Control and Prevention, US Department of Health and Human Services |
Managing the risk of trichinosis for feral pig hunters
There is a risk that feral pigs may be infected with Trichinella. This means pig hunters are particularly important in the management and control of this parasite. Hunters should be aware of the following:
- Capture, transfer and release of feral pigs can spread infection into new areas, and should not occur.
- When feral pigs are captured and killed, discarded offal and off-cuts should be buried to avoid scavenging by wild animals, perpetuating infection in wildlife reservoirs.
- Persons butchering feral pigs and handling meat should take standard hygienic precautions, such as thoroughly washing hands, knives and preparation surfaces following contact with raw meat.
It is illegal to sell or trade meat unless you are a licensed commercial operator.
Managing the risk of trichinosis in domestic pigs
Farmers, both pig farmers and persons who rear pigs for their own use, should be aware of the following measures to reduce the risk of domestic pigs becoming infected with Trichinella:
- Keeping captured feral pigs on a property where domestic pigs are reared may transfer infection to the domestic pigs.
- Domestic pigs should be retained by suitable housing or fencing and receive adequate food from a controlled source to prevent them wandering and scavenging freely.
- If vermin are present, particularly rats and mice, control should be undertaken to minimise opportunities for contact with domestic pigs.
- Meat derived from home-killed or feral animals should either not be fed to pigs or should be thoroughly cooked prior to feeding.
Homekill and recreational (wild or feral) catch meat
Homekill is the slaughtering and butchering of your own animal for your own consumption and use, and includes the use and consumption by the owners family or household. Homekill cannot be traded or sold in any way.
Recreational catch is a wild animal that has been hunted and is for the use of the hunter (including members of the hunter’s party, family or household). An example is feral pork. Recreational catch cannot be traded or sold in any way.
Homekill and recreational catch may be slaughtered or processed by a listed homekill and recreational catch service provider. The service provider must return all homekill or recreational catch to the animal owner or hunter. Waste material should be disposed of by deep burial, incineration or other secure methods approved by waste management providers.
Homekill and recreational catch products are not subject to any hygiene or safety regulations, so neither MAF nor Ministry of Health can give assurances on the fitness of the resulting products. People who use or consume homekill or recreational catch do so at their own risk. People preparing and consuming meat from home kill or recreational catch should observe good food handling practices including:
- Wash hands before and after handling meat.
- Knives, chopping boards and other equipment must be washed thoroughly after butchering or cutting up all meat, homekill or recreational catch.
- Cook homekill or recreational catch meat thoroughly right through before eating.
- Care should be taken when thawing homekill or recreational catch meat to ensure the juices do not contaminate other products in the fridge.
|