26/07/2019
African swine fever (ASF) is a highly contagious haemorrhagic viral disease of domestic and wild pigs, which is responsible for serious economic and production losses.
It is caused by a large DNA virus which also infects ticks of the genus Ornithodoros.
The tick will ingest the virus when taking a blood meal and then pass it on when
feeding on susceptible animals.
The virus is found in all body fluids and tissues of infected domestic pigs.
It is a transboundary animal disease and can be spread by live or dead pigs, domestic or wild, and pork products.
Direct contact with infected pig or wild pig.
Indirect transmission through infected vector tick.
Transmission can also occur via contaminated feed and objects such as shoes, clothes, vehicles, knives, equipment etc., due to the high environmental resistance of ASF virus.
Acute forms of ASF are characterised by high fever, depression, anorexia and loss of appetite, redness of skin on ears, abdomen and legs.
Pregnant sows will abort, cyanosis, vomiting, bleeding from the nose and re**um, diarrhoea and death within 6- 10 days.
In severe cases, a farmer might lose his entire stock.
Chronic forms are caused by less virulent viruses, and produce less serious clinical signs that can last longer.
Mortality rate in the chronic form may still reach 70%
Chronic disease symptoms include loss of weight, intermittent fever, respiratory problems, skin ulcers and joint problems.
Different types of pig may have varying susceptibility to ASF virus infection. African wild pigs may be infected without showing clinical signs allowing them to act as reservoirs.
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Currently there is no approved vaccine for ASF and no treatment.
Prevention in countries free of the disease depends on implementation of appropriate import policies and biosecurity measures.
Ensuring that neither infected live pigs nor pork products are introduced into areas free of ASF.
During outbreaks , early detection and humane killing of animals (with proper disposal of carcases and waste); thorough cleansing and disinfection strict biosecurity measures on farms can help reduce the spread of the disease.
Public health risk
ASF is not a risk to human health.
ASF is a disease listed in the World Organisation for Animal Health (OIE) Terrestrial Animal Health Code and must be reported to the OIE.
