African swine fever: An update

Posted on December 20, 2018 by Duncan Berkshire

African swine fever (ASF) is a devastating and often fatal disease which has been spreading in parts of eastern and central Europe since 2007. It has now been reported in the Baltic States, Poland, Romania, Moldova, the Czech Republic, Hungary, Ukraine, Bulgaria, Russia and China. Most recently, and indeed concerning, has been the latest recent jump of the virus to the south eastern area of Belgium – very close geographically to the UK and with a higher chance of spread through trade routes.

Defra announced that the risk of an incursion of African Swine Fever in the UK had risen from ‘Low’ to ‘Medium’ in September 2018 following the geographical spread of the disease spread into Bulgaria and the Belgium outbreak.

If the disease were to reach the UK it would have a devastating effect on the domestic pig population and would potentially necessitate the humane culling of pigs to prevent further spread.

Risks from infected meat

Many cases in Europe have been linked to wild boar spread, potentially following a jump from a previously affected area in contaminated meat products. Similarly, the biggest risk of infection for the UK pig population is from pigs getting access to infected meat products brought into the UK. The ASF virus can survive for many months in smoked, dried and cured meats, and in frozen meat. These products would most likely be personal imports, since commercial trade of pork or pork products is not permitted from affected countries.

If you keep pigs, you should already be aware that it is illegal to feed them kitchen scraps, catering waste or domestic food waste, including vegetarian or vegan products (due to potential cross contamination). This ban helps to protect the UK from diseases such as ASF. It is also strongly advised that anyone with direct contact with pigs washes their hands after eating and before further contact with pigs.

The importance of good biosecurity

The second possible route of infection is through lapses in biosecurity. ASF survives in pig faeces and in the blood of infected pigs or wild boar meaning the virus can be spread on vehicles, equipment, clothing and boots contaminated by infected pigs or wild boar. This makes it especially important that anyone who has visited an ASF-affected area, particularly those who keep pigs or work on pig farms, avoid unknowingly bringing back infection.

Defra advises pig farmers to protect their animals by:

  • Using dedicated clothing and boots for you and anyone coming onto your premises.
  • Preventing vehicles or equipment from coming on to your premises unless cleaned and disinfected first.
  • Ensuring that people who look after or visit your pigs understand the disease risk of bringing back meat products, particularly wild boar meat or pork products from affected countries.
  • Not allowing any pork products to be brought onto the farm to avoid accidental access to pigs.

Feral wild boar in the UK

Although infected wild boar in Europe pose little risk to pigs in the UK directly, there is a very real risk that feral pigs, in areas such as the Forest of Dean, Sussex, Kent, Dorset, Central Perthshire, Dumfriesshire and Lochaber, could become infected and thereby spread the disease to domestic pigs. The total risk from these populations is currently unknown since we do not know their sizes, although they are thought to be expanding in numbers and widening their territories with very little control being employed to halt this.

If you are suspicious of the presence of this disease you are legally obligated to report it to your local animal health and welfare services, and members of the public should be advised that they must not feed these animals, particularly with food waste and that they should ensure that wild or feral pigs cannot gain access to domestic or catering waste in rubbish.

Signs and symptoms of African Swine Fever

The signs of African Swine Fever can be found on Defra's website: “African swine fever: how to spot and report the disease”.

Pigs with clinical African Swine Fever most commonly show signs of fever, inappetance, lack of energy and sudden death. There may also be signs of vomiting, diarrhoea, red or dark skin, laboured breathing or coughing, abortion, stillbirths and weak piglets at birth.

This is a rapidly spreading disease with no vaccine to help control its effects or movement. There is no risk to human health from this infection, but it could have an enormous impact on pigs in this country and would devastate our pig sector. We can all play a role in keeping ASF out of the UK by following good biosecurity and keeping food waste away from both pigs and feral wild boar.

Duncan Berkshire

Written by Duncan Berkshire

Duncan joined the pig department at Bishopton in 2009 having previously worked extensively with pigs in Yorkshire since graduation. He qualified from Cambridge Vet School in 2004 and obtained his Masters in Livestock Health and Production with the Royal Veterinary College while in practice. Duncan also holds the RCVS Certificate in Pig Medicine. Improving herd health and reproductive physiology are particular areas of interest, along with farm based investigations to introduce preventative medicine programmes on unit. He is currently President of the Pig Veterinary Society.