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Just released! - the 'official' England and Wales Best Practice Guide for wild boar carcass handling |
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Public health is relevant to the wild boar's re-introduction because new animals may bring new diseases or may increase the incidence of disease already present. Wild boar are vulnerable to parasitic and bacterial disease and several of their parasites and infections are transmissible to man. Shot wild boar in Britain have been butchered and skinned in an unregulated environment but it is not known whether any disease has occurred as a result.
Trichinellosis is one of the most important zoonotic threats to human health from consuming wild boar meat, but the boar in Britain do not constitute a major public health risk. In contrast, about one-fifth of the human cases that have occurred in France, Germany, Italy and Spain, were caused by the consumption of meat from wild boar.
The Food Standards Agency (FSA) has decided that as the UK's wild boar are potential sources of infection, they must be brought into the EU's Trichinella monitoring system. To assist with this, a 'Guidance for Trichinella Testing in Feral Wild Boar' leaflet has been issued for the benfit of people involved in wild boar management, which includes a testing kit with full instructions.
The kit allows hunters to test carcasses forTrichinella. It applies to those hunting wild boar for their own consumtion and those supplying shops or restaurants. The results will contribute to a wildlife monitoring programme and reassure hunters that they are not about to infect anyone with a nasty worm disease.
The trichinella testing kit is available free to anyone involved in wild boar management that wishes to participate.
Kits can be acquired by emailing wildgameguidance@foodstandards.gsi.gov.uk.
Trichinosis is a disease caused by the larvae, 'trichinae', of a small nematode worm (Trichinella spiralis), which may infect many species including humans. People can become infected by eating raw, undercooked or processed meat from pigs, wild boar, horses or game that contain the trichinae.
Symptoms in people are very variable and milder cases of the disease may be difficult to diagnose. There may be fever, muscle and joint pains, diarrhoea, and swelling around the eyes. More severe cases may develop neurological or cardiac complications which occasionally can be fatal
Except in severs cases animals infected with Trichinella generally show no outward sign of infection. Like humans, animals can become infected when they ingest meat containing the trichinae In the case of food species, such as wild boar, the potential sources of infection are the consumption of dead infected animals, either directly or from contaminated commercial animal feeds.
A number of wildlife species can also carry Trichinella including foxes and rodents. Wildlife can become infected through the consumption of other wildlife or by scavenging through refuse that contains infected meat.
In Britain there have been no confirmed human case of trichinosis from meat produced in the UK since 1969. The last reported case in a domestic pig was 1979, however it was found in a fox in 2007. Both of these cases occurred in Northern Ireland. The disease is widespread in Europe and is of great concern to the relevant authorities.
Concerning the wild boar in the Britain, the Food Standards Agency note that although the wild boar population in Britain is small, it is not insignificant. As well as the risk from consumption of infected wild boar meat there is a risk due to the interaction of wild boar with domestic pigs, which can involve interbreeding. Infection can only be contracted in humans by consumption of undercooked meat undercooked infected meat. Trichinae are killed by thorough cooking.
The life cycle of Trichinella.
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Trichinella cyst in muscle layer.
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Trichinellosis is acquired by ingesting meat containing cysts (encysted larvae) (1) of Trichinella. After exposure to gastric acid and pepsin, the larvae are released (2) from the cysts and invade the small bowel mucosa where they develop into adult worms (3) (female 2.2 mm in length, males 1.2 mm; life span in the small bowel: 4 weeks). After 1 week, the females release larvae (4) that migrate to the striated muscles where they encyst (5). Trichinella pseudospiralis, however, does not encyst. Encystment is completed in 4 to 5 weeks and the encysted larvae may remain viable for several years. Ingestion of the encysted larvae perpetuates the cycle. Rats and rodents are primarily responsible for maintaining the endemicity of this infection. Carnivorous/omnivorous animals, such as pigs or bears, feed on infected rodents or meat from other animals. Different animal hosts are implicated in the life cycle of the different species of Trichinella. Humans are accidentally infected when eating improperly processed meat of these carnivorous animals (or eating food contaminated with such meat).
Regarding Game Meat Production interests,the Food Standards Agency has 'no long term proposals for feral wild boar other than to encourage hunters to take a sample of wild boar and send it to a laboratory for testing for trichinella with all the costs being met by the Agency' (Ref: http://www.food.gov.uk/multimedia/pdfs/consultationresponse/hygamendeng08resp.pdf).
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