African Swine Fever - Fact Sheet

What is African swine fever?

African swine fever (ASF) is a contagious viral disease of swine.

In Africa, the virus is found in wild pigs (warthogs and bush pigs) but they do not show clinical signs; therefore, they act as a reservoir of the virus.

Some species of pigs are more likely to get the disease. ASF can cause high death rates in infected:

  • domestic pigs
  • European wild boars, and
  • American wild pigs.

The virus can survive for several months in fresh pork and processed pork products.

Is ASF a risk to human health?

No. There is no human health risk associated with ASF.

What are the clinical signs of ASF?

The clinical signs of ASF range from mild to severe and may be very similar to those of classical swine fever.

ASF can cause high death rates in affected herds and can cause the animal to bleed internally. The most damaging strains of ASF virus cause the following symptoms:

  • bleeding in the skin and internal organs
  • bloody diarrhea
  • high fever
  • loss of appetite
  • vomiting

With these strains of ASF, almost 100 percent of infected pigs will die. Less harmful strains produce milder clinical signs such as slight fever, reduced appetite and depression.

Clinical signs of chronic ASF include extreme weight loss, pneumonia, and enlarged lymph nodes. African wild swine (warthogs and bush pigs) do not show clinical signs when they are infected.

Where is ASF found?

The disease is present in most countries of sub-Saharan Africa.

ASF has never been found in Canada.

How is ASF transmitted and spread?

ASF can be spread directly between sick and healthy pigs. This happens through contact with blood, tissues, secretions, and excretions from infected pigs.

The blood of a recently-infected pig contains a very high level of ASF virus.

Animals that recover may become persistent carriers. The virus also persists in the body tissues after death. The main way it is transmitted from country-to-country is through people feeding pigs uncooked food scraps that are infected with the virus.

It can also be spread by indirect means. Soft ticks have been shown to carry the virus. In Africa, they are considered to be the primary mode of transmission, particularly between the native wild hogs and domesticated animals.

Because the ASF virus can survive for long periods of time outside of the host, it can be spread by contamination of objects, such as farm equipment, clothes and livestock feed.

How is ASF diagnosed?

An owner or veterinarian may suspect ASF based on clinical signs and disease lesions in affected pigs, and a high death rate in affected herds.

Laboratory tests are essential to detect the virus and confirm the diagnosis.

How is ASF treated?

There is no treatment or vaccine for ASF.

What is done to protect Canadian livestock from an outbreak of ASF?

The Canadian Food Inspection Agency (CFIA) imposes strict regulations on the import of animals and animal products from countries where ASF is known to occur. These regulations are enforced through point-of-entry inspections done either by the Canada Border Services Agency or the CFIA.

ASF is a is a reportable disease under the Reportable Diseases Regulations, and all cases must be reported to the Canadian Food Inspection Agency (CFIA).

How would the CFIA respond to an outbreak of ASF in Canada?

Canada's emergency response strategy to an outbreak of ASF would be to

  • eradicate the disease, and
  • re-establish Canada's disease-free status as quickly as possible.

In an effort to eradicate ASF, the CFIA would use its "stamping out" policy, which includes

  • the humane destruction of all infected and exposed animals,
  • surveillance and tracing of potentially infected or exposed animals,
  • strict quarantine and animal movement controls to prevent spread,
  • strict decontamination of infected premises, and
  • zoning to define infected and disease-free areas.

Owners whose animals are ordered destroyed may be eligible for compensation.

Additional information

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