African swine fever is a particularly dangerous contagious virus disease of domestic and feral pigs as well as wild boars. This virus is transmitted by direct contact through excreta, blood or semen. It can be also transmitted by ticks of Ornithodoros species. Animals can be also infected with African swine fever by indirect contact: through infected items, clothes, transport, feed, raw materials, etc.
This disease is transmitted through placenta to foetus. Birds, flies or humans can physically transmit the virus from infected pigs to healthy ones. The owner of pigs can introduce the infection by feeding pigs with untreated food waste containing animal origin products. Spread of the virus of African swine fever is lightning-fast irrespective of the season, age of pigs and their breed. It is resistant to environmental factors, heat and cold.
Only domestic and feral pigs and wild boars can be infected by African swine fever. The virus causing this disease does not pose any threat to other animals or humans. The consumption of meat of infected animals is prohibited not because of the threat for humans to get infected but because of the threat that the dangerous virus might be spread beyond the infection area through meat, blood or internal organs. African swine fever is a disease without any danger to humans as they will not get infected even if they eat some infected meat. The State Food and Veterinary Service assures that the pig meat sold in Lithuania is safe for consumption.
The symptoms of African swine fever:
- fever (40.5 – 42 °C);
- early-onset leukopenia and thrombocytopenia (48–72 hours);
- skin redness (in white pigs) around ears, tail, distal limbs, abdomen and chest;
- anorexia, cyanosis and incoordination (manifests within 24–48 hours before death);
- increased pulse rate and breathing rate;
- vomiting an diarrhea (sometimes containing blood);
- Death usually occurs within 6 –13 days after infection, however, it can also occur after 20 days;
- can cause abortions for sows;
- the mortality rate for domestic pigs is 100 per cent.
Pig owners, in case of a suspicion that their animals are sick, must immediately approach the local private veterinarian or specialists of the territorial State Food and Veterinary Service. They can also call the free telephone line +370 800 40 403, 24 hours a day.
The sick pigs must be isolated from the healthy ones until the cause of the sickness is diagnosed.
There have not been any treatment methods or an effective vaccine developed against African swine fever so far. Therefore, infected pigs are not treated, they are destroyed instead. In order to prevent the spread of the virus not only the carrions of pigs are destroyed (incinerated or buried in pits of at least 2 m deep) but also low-value assets and feedingstuffs kept at the farm.
Pig houses and their environment shall be disinfected three times. Having established that the disinfection of the houses is not effective, a decision can be taken that they have to be destroyed as well.
Losses incurred as a result of eradication of an outbreak of the disease are covered only for registered pigs.
Zones of African swine fever
The buffer zone is a protective area subject to most stringent biosaferty requirements. Areas in Lithuania falling under the buffer zone
The territory of Lithuania was divided by the European Commission into three zones.
Zone I is a territory at risk. No restrictions are applied for trade in live pigs and their export in this zone. Farms must comply with biosafety requirements. Regular control and surveillance of pig keeping places is carried out. Areas in Lithuania falling under the zone I
Zone II is an infected area where ASF was detected in wild fauna (wild boars). Restrictions on the movement of pigs from their keeping places are applied (the keeping places must comply with biosafety requirements, regular official veterinary control is carried out), trade in live pigs is allowed only within the territory of the Republic of Lithuania. The export of live pigs for trading purposes to the EU or third countries is prohibited. Only pig meat and pig meat products coming from officially recognised farms, which apply strict biosafety requirements, are allowed to be marketed. The consignment of wild boars and their products from the territory of the Republic of Lithuania to the EU and third countries is prohibited. Areas in Lithuania falling under the zone II
Zone III is an infected area where ASF was detected in wild boars and domestic pigs. The movement of live pigs is allowed only within the territory of Lithuania and only from the farms, which have fully implemented biosafety requirements. The trading in pig meat and pig meat products is allowed only on the domestic market. The products must be marked with the special health mark. The export of live pigs, pig meat and products therefrom to the EU and third countries is prohibited. Areas in Lithuania falling under the zone III
The same area may be assigned both to the buffer zone, zone I, II or III.
The outbreak zone refers to a farm holding where infected pigs were detected as well as contact farm holdings where infected pigs were brought. All the pigs in the outbreak zone must be slaughtered.
As soon as African swine fever is officially confirmed for pigs kept in a farm holding, the competent authority shall within the radius of 3 km around the place of the outbreak of the disease establish a protection zone and within the radius of 10 km – a surveillance zone.
Within the 3 km protection zone, all pig keepers and pigs kept by them must be recorded as soon as possible and samples shall be taken for the analysis of African swine fever from each pig. Upon instruction of the SFVS, a decision can be taken to slaughter all the pigs kept within the 3 km protection zone. However, after an ante-mortem clinical examination has been conducted, blood and organ samples have been collected and a negative result of the analysis for African swine fever have been obtained, meat of such pigs can be used for own consumption.
Within the 10 km surveillance zone, all pig keepers and the numbers of pigs kept by them must be recorded as soon as possible and samples shall be taken for the analysis of African swine fever from each pig.