African Swine Fever

NPA advice

• Only absolutely essential visitors should be allowed on pig farms and they must have entered Britain at least three days before the visit. Only unit clothing and footwear should be worn on the unit.
   
• If you return from overseas yourself, allow three days before considering yourself pig-free.
   
• Ensure all staff and colleagues are aware of the risks posed by African swine fever and that they comply with all biosecurity measures when visiting any pig unit.
   
• As a matter of principle no pork products should ever be allowed on pig units, because of their potential to introduce serious diseases.
   
• If in eastern Europe, avoid all pigs and wooded areas where wild boar might be present.
   
• If in eastern Europe, ideally do not bring back clothes and footwear worn in wild boar areas or on farms. Under no circumstance return to work wearing the same clothes.
   
• Do not bring back food products, especially pork.

Keep African swine fever out of Britain

African swine fever is a highly contagious notifiable disease of pigs. It can occur in acute, sub-acute or chronic forms. The acute form causes severe disease from which the majority of affected pigs die. ASF has not—yet—occurred in Great Britain.

The disease has spread from Russia to the Ukraine and Belarus and has now been carried by wild boar into Lithuania, Latvia, Poland and Estonia in the European Union.

Because many British pig unit workers are from eastern Europe there is a heightened risk of the disease entering a British unit.

All pig-keepers should be aware of these risks and make sure their employees and companies that deliver to the unit are similarly well informed.

The most likely route of the disease into Britain is via infected meat products getting onto a pig unit. African swine fever will survive for many weeks, even months, in raw, cured and cooked meats, and on objects such as vehicles, equipment and clothes.

Symptoms to watch for

The key to control is early detection—so all pig-keepers must report any clinical signs of the disease, which are very similar to classical swine fever.

The chronic form is not usually seen in outbreaks—it is more likely to be found in areas where the disease is endemic.

In severe outbreaks the incubation period is 5-7 days and pigs rapidly become feverish. Many die after 7-10 days of illness with a variety of non-specific clinical signs including haemorrhage. In acute infections, the pigs die so rapidly that the only sign of disease is sudden death.

Milder strains of the virus can cause less severe illness with a longer incubation period (5-19 days).
Other symptoms seen are variable but will include some or all of the following:

• Vomiting
• Diarrhoea (sometimes bloody)
• Reddening or darkening of the skin, particularly ears and snout
• Gummed-up eyes
• Laboured breathing and coughing
• Abortion, still births and weak litters
• Weakness and unwillingness to stand.

How it spreads

ASF can be spread by:

• Direct contact with infected pigs, faeces or body fluids.
• Indirect contact via equipment, vehicles etc or people who work with pigs moving between pig farms with ineffective biosecurity.
• Pigs eating infected pigmeat or meat products.

African swine fever will survive for 15 weeks in putrefied blood, three hours at 50C, 70 days in blood on wooden boards, 11 days in faeces held at room temperature, 18 months in pig blood held at 4C, 150 days in boned meat held at 4C and 140 days in salted dried hams.

Treatment

Notification, movement restrictions, slaughter, incineration.