African swine fever
African swine fever is a viral disease of pigs and wild boar that is usually deadly. There are neither vaccines nor cures. For this reason, it has serious socio-economic consequences in affected countries. Humans are not susceptible to the disease.
The typical signs of African swine fever are similar to classical swine fever, and the two diseases normally have to be distinguished by laboratory diagnosis. Symptoms include fever, loss of appetite, lack of energy, abortions, internal bleeding, with haemorrhages visible on the ears and flanks. Sudden death may occur. Severe strains of the virus are generally fatal (death occurs within 10 days). Animals infected with mild strains of African swine fever virus may not show typical clinical signs.
Transmission and spread
Healthy pigs and boar usually become infected by:
- Contact with infected animals, including contact between free-ranging pigs and wild boar.
- Ingestion of meat or meat products from infected animals – kitchen waste, swill feed, infected wild boar (including offal).
- Contact with anything contaminated by the virus such as clothing, vehicles and other equipment.
- Bites by infectious ticks.
Movement of infected animals, contaminated pork products and the illegal disposal of carcasses are the most significant means of spread of the disease.
Where is it found?
African swine fever is endemic in sub-Saharan Africa. In Europe, it has been endemic in Sardinia for several decades. In 2007 outbreaks occurred in Georgia, Armenia, Azerbaijan and the European part of Russia, Ukraine, and Belarus.
Recent outbreaks in the European Union
From Russia and Belarus, the disease spread to the European Union. Lithuania reported cases of African swine fever in wild boar for the first time in January 2014. Poland followed in February 2014 and Latvia and Estonia in June and September of the same year.
Most outbreaks occurred in small farms and were contained relatively quickly. The disease is still spreading locally among wild boar, where containment is more difficult.
Acquiring knowledge on wild boar populations is a key issue for risk assessment on ASF and planning control measures. Still the understanding of distribution of this wild animal species is not clear. To fill these gaps, EFSA is funding a project – ENETWILD – aimed at collecting and harmonising data on the geographical distribution and abundance of wild boar across Europe.
EFSA has tracked the situation of African swine fever closely over the years, including after the 2014 outbreaks in Baltic countries and Poland.
2017 – EFSA experts assisted Baltic countries and Poland in the analysis of epidemiological data collected up until September 2017.
March 2017 – An epidemiological analysis by EFSA and Member States concluded that African swine fever is spreading slowly in the Baltic countries and Poland.
2015 – Experts recommended a combination of different management measures to reduce the spread of the disease among wild boar. These included targeted hunting, removal of carcasses in the wild and a strict feeding ban.
March 2014 – In their urgent scientific advice following the outbreaks in Poland and Lithuania, experts concluded that hunting is not an effective tool to drastically reduce the size of the wild boar population in Europe. Also, artificial feeding of wild boar might increase it.
April 2014 – Experts said that the risk of African swine fever becoming endemic in Georgia, Armenia and Russia had increased from moderate to high since 2010, when EFSA carried out its last risk assessment. In addition, the risk of the virus spreading further into unaffected areas from these countries through contaminated meat, animals or vehicles remained high.
March 2010 – EFSA assessed the risk of the disease remaining endemic in the countries neighbouring the EU (Caucasian countries and Russia) – qualifying it as “moderate” – and the risk of introduction of the disease into the European Union.
July 2010 – EFSA experts concluded that ticks are important in maintaining the virus locally, but do not play an active role in its geographical spread.
EFSA’s Panel on animal health and welfare provides independent scientific advice on animal health and related food safety issues to risk managers, namely the European Commission, European Parliament and Member States.
Experts have provided scientific advice on African swine fever several times over the past years. This included:
- Assessing the risk of introduction of African swine fever into the European Union
- Looking at the role of vectors, namely ticks, in the spread of the disease
- Supporting Member States in standardising the way they collect data
- Providing epidemiology updates – information on the incidence, distribution, and possible control measures