Pathfinder
Editor, Senior Moderator
African swine fever: significant increase in EU pigs in 2023
Published:
16 May 2024
In 2023, 14 Member States were affected by African swine fever (ASF) and it caused a five-fold increase in outbreaks in domestic pigs compared to the previous year. These are the main findings of the latest annual epidemiological report published by EFSA today.
For domestic pigs, 2023 saw the largest number of African Swine Fever (ASF) outbreaks since 2014. Croatia and Romania notified 96% of the total number of outbreaks (1,929).
The number of outbreaks in 2023 in wild boar increased by 10% compared to the previous year. The virus was introduced for the first time in Sweden and Croatia and spread to new areas of Italy. It also re-appeared in Greece after a two-year break.
Germany, Hungary and Slovakia saw the epidemiological situation improve in their countries with the number of outbreaks in wild boar decreasing.
EFSA’s experts recommend prioritizing passive surveillance , including the searching and testing of wild boar carcasses, rather than active surveillance, including the testing of hunted wild boar for the detection of ASF outbreaks.
Passive surveillance, in particular noticing clinical signs of the disease remains the main mode of detection for ASF also in domestic pig establishments. Therefore, farmers and vets have a particularly important role to play in reporting suspicious cases.
In October 2024, EFSA will deliver a scientific opinion revising the risk factors for the emergence, spread and persistence of the ASF virus in wild boar populations as well as in domestic pigs. Our advice will support risk managers in their ongoing efforts to prevent, control and eradicate the spread of the ASF virus.
...
https://www.efsa.europa.eu/en/news/african-swine-fever-significant-increase-eu-pigs-2023
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SCIENTIFIC REPORT
Open Access
Epidemiological analysis of African swine fever in the European Union during 2023
European Food Safety Authority (EFSA), Karl Ståhl, Anette Ella Boklund, Tomasz Podgórski, Timothée Vergne, José Cortiñas Abrahantes, Eleonora Cattaneo, Alexandra Papanikolaou, Lina Mur
First published: 16 May 2024
https://doi.org/10.2903/j.efsa.2024.8809
Approved: 24 April 2024 SECTIONS
PDF
Abstract
In 2023, 14 Member States were affected by African swine fever (ASF), including Croatia and Sweden where ASF emerged (wild boar outbreaks only) and Greece where ASF re-emerged after being free since 2021. The number of ASF outbreaks among domestic pigs in the EU was five times higher than in 2022, reaching a similar magnitude to that in 2019. This was predominantly driven by the introduction and subsequent spread of ASF in Croatia and its resurgence in Romania, representing 96% of the EU outbreaks. ASF outbreaks in domestic pigs were clearly seasonal in all countries, with 88% of outbreaks reported between July and October. Most of the ASF outbreaks among domestic pigs were detected through clinical suspicion (94%), followed by tracing from affected establishments (3%), and the weekly testing of at least two dead pigs in establishments (3%). In wild boar, a 10% increase in the number of notified outbreaks was observed in the EU in comparison with 2022, with considerable variations between countries. A winter peak was observed only in Poland, Slovakia and Hungary. The epidemiological situation in wild boar improved in Germany and Hungary, as suggested by the decrease in the number of outbreaks and in the proportions of PCR-positive samples from dead wild boar. Overall, 31% of wild boar carcasses found during passive surveillance tested positive by PCR, representing 69% of the ASF outbreaks in wild boar in the EU. In contrast, 0.4% of hunted wild boar tested positive, representing 31% of the outbreaks. Despite the introduction of ASF into new countries and the increase in the number of outbreaks, the size of restricted zones in the EU remained stable, due to the highly clustered outbreaks in Croatia, and the reduction of restricted zones in Poland, Slovakia and Bulgaria (in domestic pigs), and Hungary (in wild boar).
SUMMARY
The European Food Safety Authority (EFSA) has a mandate from the European Commission (EC) to generate annual epidemiological analyses of the spread and impact of African swine fever (ASF) genotype II in the European Union (EU) and neighbouring countries affected by ASF. In this context, affected Member States and non-EU countries and territories that notified ASF during 2023 to the Animal Disease Information System (ADIS) and, where relevant, benefit from the Instrument for Pre-accession Assistance programme, were invited to submit laboratory test results from ASF surveillance activities and pig population information to EFSA. These data were used in combination with other data sources to produce this report. These additional sources include official ASF outbreaks and outbreak information among wild boar and domestic pigs (ADIS), the wild boar hunting bags and abundance estimates (ENETWILD et al., 2022) and restricted zone data (as provided by European Commission).
The number of notified outbreaks of ASF among domestic pigs in the Member States was five times higher than in 2022, reaching a similar magnitude to that in 2019. This increase was largely driven by the ASF emergence in Croatia (1124 outbreaks) and the resurgence in Romania (736 outbreaks), as these two countries accounted for 96% of the EU outbreaks in 2023. While all the outbreaks in Croatia were notified only in three regions bordering Bosnia and Herzegovina and Serbia, the outbreaks in Romania were reported across the country, similar to the situation in 2022. In the rest of the EU, the outbreaks among domestic pigs were sporadic (30 in Poland, 16 in Italy and fewer than 10 in the remaining 6 affected Member States). Across the EU, ASF in domestic pigs was notified in 11 NUTS 3 regions that had never been affected before (compared with 5 in 2022), located in Croatia, Greece, Germany, Italy and Poland, indicating a wider spread to new areas. Most of the outbreaks (96%) occurred on small establishments with fewer than 100 pigs, and the six outbreaks that occurred on establishments with more than 10,000 pigs were all in Romania.
In the non-EU countries and territories, ASF was detected for the first time in Bosnia and Herzegovina and Kosovo.[SUP]1[/SUP]* A very important increase was observed in the number of notified outbreaks (18 times more), driven by the emergence and spread in Bosnia and Herzegovina and the sharp increase in incidence in Serbia (nine times more outbreaks than in 2022). These two countries accounted for 99% of the notified outbreaks in domestic pigs among the non-EU countries and territories included in the report.
In the Member States, 94% of the outbreaks among domestic pigs were detected through passive surveillance based on clinical suspicion, 3% were identified through contact tracing from affected establishments, and 3% (54 outbreaks) were found as the result of enhanced passive surveillance based on the weekly testing of at least two dead pigs per establishment. In the EU, all 6 outbreaks that occurred in establishments with more than 10,000 pigs and 5 out of the 12 outbreaks that occurred in establishments with between 1000 and 10,000 pigs were detected through the enhanced passive surveillance. No outbreaks were detected through active surveillance targeting healthy pigs at slaughter, before movement, or randomly selected at establishments. A clear summer seasonality of ASF in domestic pigs was observed, with 88% of the outbreaks reported between July and October. This seasonality was particularly clear for the small-scale establishments of fewer than 100 pigs, which accounted for most of the outbreaks notified in the EU (96%).
In wild boar, despite the introduction into new countries (Croatia, Greece and Sweden) and the spread in new areas of Italy, only a small increase (10%) in the number of notified outbreaks was observed in the EU in comparison with 2022, with considerable variations between countries. In 2023, ASF was notified in wild boar in 17 NUTS 3 regions that had never been affected before (compared with 14 regions in 2022), located in Croatia, Sweden, Italy, Germany, Greece, Poland and Slovakia. In the non-EU countries and territories, ASF was notified in wild boar in Bosnia and Herzegovina and in some new areas of north-west Serbia, with an increase in the number of notified outbreaks. Among Member States, Poland notified the largest number of ASF outbreaks in wild boar with 2686 outbreaks, representing 34% of the outbreaks in the EU. In the non-EU countries and territories, Serbia notified 213 outbreaks among wild boar, representing 70% of the outbreaks outside the EU.
Around 92% of the wild boar samples analysed were taken from hunted wild boar. Around 0.4% of them tested positive by PCR leading to the detection of 31% of the wild boar outbreaks. In contrast, samples taken from found-dead and road-killed wild boar accounted for 7.9% of the wild boar samples analysed. Around 31% of them tested positive by PCR leading to the detection of 69% of the wild boar outbreaks in the EU. A clear seasonality with winter/early spring peaks in the proportion of PCR-positive samples was observed in Poland, Slovakia and Hungary. However, no clear seasonal patterns could be observed in the other affected Member States. Seasonal patterns probably reflect a combination of ecological factors (e.g. seasonality in transmission rates or in carcass detection probability due to vegetation) and human factors (e.g. seasonality in carcass search effort and hunting intensity). In Germany and Hungary, a decreasing trend in both the proportion of PCR-positive samples from dead wild boar and the total number of notified outbreaks was observed. In Slovakia, a similar improvement was observed in the proportion of PCR-positive samples, but only since 2022.
Despite the introduction of ASF into previously unaffected countries and the increase in the number of outbreaks, particularly in domestic pigs, the restricted zones in the EU remained relatively stable. The total size of the restricted zones III, reflecting ASF in domestic pigs, was slightly reduced (−4%). This was influenced by the highly clustered outbreaks in Croatia, and the reduction of the restricted zone III in Poland, Slovakia and Bulgaria. The size of restricted zone II, reflecting ASF presence in wild boar, slightly increased in 2023 due to the new countries affected (Sweden, Croatia and Greece) and spread in previously affected ones (Italy, Slovakia and Lithuania), while it decreased in Hungary.
A decrease in the number of pig establishments, especially small establishments (< 100 pigs), was observed in Lithuania (−20%), Latvia (−17%) and Italy (−19%). In contrast, the number of small establishments increased in Romania (+27%), simultaneously with an increase in the incidence of ASF (from 0.1% to 0.2%) in comparison with 2022. The direct losses were highly concentrated in areas where the larger outbreaks were notified (e.g. the biggest outbreaks with more than 10,000 pigs were located in four regions of Romania).
In the Member States, the overall number of dead or killed wild boar positive to ASF notified to ADIS increased by 9% compared to 2022. However, there is considerable variation between countries. In Germany, this metric decreased by 44% between 2022 and 2023. In contrast, in Bulgaria, Poland and Italy, it increased by 73%, 60% and 290%, respectively. The analysis of the annual hunting bags at country level identified an increase in the wild boar population in the Baltic States, a decrease in Germany, Hungary, Romania, Poland and Slovakia, and a stable trend in Bulgaria. The decreasing trends in Romania, Hungary and Slovakia since the introduction of ASF follow a similar pattern observed in the Baltics in the first few years post-introduction.
...
https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2024.8809
Published:
16 May 2024
In 2023, 14 Member States were affected by African swine fever (ASF) and it caused a five-fold increase in outbreaks in domestic pigs compared to the previous year. These are the main findings of the latest annual epidemiological report published by EFSA today.
For domestic pigs, 2023 saw the largest number of African Swine Fever (ASF) outbreaks since 2014. Croatia and Romania notified 96% of the total number of outbreaks (1,929).
The number of outbreaks in 2023 in wild boar increased by 10% compared to the previous year. The virus was introduced for the first time in Sweden and Croatia and spread to new areas of Italy. It also re-appeared in Greece after a two-year break.
Germany, Hungary and Slovakia saw the epidemiological situation improve in their countries with the number of outbreaks in wild boar decreasing.
EFSA’s experts recommend prioritizing passive surveillance , including the searching and testing of wild boar carcasses, rather than active surveillance, including the testing of hunted wild boar for the detection of ASF outbreaks.
Passive surveillance, in particular noticing clinical signs of the disease remains the main mode of detection for ASF also in domestic pig establishments. Therefore, farmers and vets have a particularly important role to play in reporting suspicious cases.
In October 2024, EFSA will deliver a scientific opinion revising the risk factors for the emergence, spread and persistence of the ASF virus in wild boar populations as well as in domestic pigs. Our advice will support risk managers in their ongoing efforts to prevent, control and eradicate the spread of the ASF virus.
...
https://www.efsa.europa.eu/en/news/african-swine-fever-significant-increase-eu-pigs-2023
------------------------------------------------------------------------------
SCIENTIFIC REPORT
Open Access
Epidemiological analysis of African swine fever in the European Union during 2023
European Food Safety Authority (EFSA), Karl Ståhl, Anette Ella Boklund, Tomasz Podgórski, Timothée Vergne, José Cortiñas Abrahantes, Eleonora Cattaneo, Alexandra Papanikolaou, Lina Mur
First published: 16 May 2024
https://doi.org/10.2903/j.efsa.2024.8809
Approved: 24 April 2024 SECTIONS
PDFAbstract
In 2023, 14 Member States were affected by African swine fever (ASF), including Croatia and Sweden where ASF emerged (wild boar outbreaks only) and Greece where ASF re-emerged after being free since 2021. The number of ASF outbreaks among domestic pigs in the EU was five times higher than in 2022, reaching a similar magnitude to that in 2019. This was predominantly driven by the introduction and subsequent spread of ASF in Croatia and its resurgence in Romania, representing 96% of the EU outbreaks. ASF outbreaks in domestic pigs were clearly seasonal in all countries, with 88% of outbreaks reported between July and October. Most of the ASF outbreaks among domestic pigs were detected through clinical suspicion (94%), followed by tracing from affected establishments (3%), and the weekly testing of at least two dead pigs in establishments (3%). In wild boar, a 10% increase in the number of notified outbreaks was observed in the EU in comparison with 2022, with considerable variations between countries. A winter peak was observed only in Poland, Slovakia and Hungary. The epidemiological situation in wild boar improved in Germany and Hungary, as suggested by the decrease in the number of outbreaks and in the proportions of PCR-positive samples from dead wild boar. Overall, 31% of wild boar carcasses found during passive surveillance tested positive by PCR, representing 69% of the ASF outbreaks in wild boar in the EU. In contrast, 0.4% of hunted wild boar tested positive, representing 31% of the outbreaks. Despite the introduction of ASF into new countries and the increase in the number of outbreaks, the size of restricted zones in the EU remained stable, due to the highly clustered outbreaks in Croatia, and the reduction of restricted zones in Poland, Slovakia and Bulgaria (in domestic pigs), and Hungary (in wild boar).
SUMMARY
The European Food Safety Authority (EFSA) has a mandate from the European Commission (EC) to generate annual epidemiological analyses of the spread and impact of African swine fever (ASF) genotype II in the European Union (EU) and neighbouring countries affected by ASF. In this context, affected Member States and non-EU countries and territories that notified ASF during 2023 to the Animal Disease Information System (ADIS) and, where relevant, benefit from the Instrument for Pre-accession Assistance programme, were invited to submit laboratory test results from ASF surveillance activities and pig population information to EFSA. These data were used in combination with other data sources to produce this report. These additional sources include official ASF outbreaks and outbreak information among wild boar and domestic pigs (ADIS), the wild boar hunting bags and abundance estimates (ENETWILD et al., 2022) and restricted zone data (as provided by European Commission).
The number of notified outbreaks of ASF among domestic pigs in the Member States was five times higher than in 2022, reaching a similar magnitude to that in 2019. This increase was largely driven by the ASF emergence in Croatia (1124 outbreaks) and the resurgence in Romania (736 outbreaks), as these two countries accounted for 96% of the EU outbreaks in 2023. While all the outbreaks in Croatia were notified only in three regions bordering Bosnia and Herzegovina and Serbia, the outbreaks in Romania were reported across the country, similar to the situation in 2022. In the rest of the EU, the outbreaks among domestic pigs were sporadic (30 in Poland, 16 in Italy and fewer than 10 in the remaining 6 affected Member States). Across the EU, ASF in domestic pigs was notified in 11 NUTS 3 regions that had never been affected before (compared with 5 in 2022), located in Croatia, Greece, Germany, Italy and Poland, indicating a wider spread to new areas. Most of the outbreaks (96%) occurred on small establishments with fewer than 100 pigs, and the six outbreaks that occurred on establishments with more than 10,000 pigs were all in Romania.
In the non-EU countries and territories, ASF was detected for the first time in Bosnia and Herzegovina and Kosovo.[SUP]1[/SUP]* A very important increase was observed in the number of notified outbreaks (18 times more), driven by the emergence and spread in Bosnia and Herzegovina and the sharp increase in incidence in Serbia (nine times more outbreaks than in 2022). These two countries accounted for 99% of the notified outbreaks in domestic pigs among the non-EU countries and territories included in the report.
In the Member States, 94% of the outbreaks among domestic pigs were detected through passive surveillance based on clinical suspicion, 3% were identified through contact tracing from affected establishments, and 3% (54 outbreaks) were found as the result of enhanced passive surveillance based on the weekly testing of at least two dead pigs per establishment. In the EU, all 6 outbreaks that occurred in establishments with more than 10,000 pigs and 5 out of the 12 outbreaks that occurred in establishments with between 1000 and 10,000 pigs were detected through the enhanced passive surveillance. No outbreaks were detected through active surveillance targeting healthy pigs at slaughter, before movement, or randomly selected at establishments. A clear summer seasonality of ASF in domestic pigs was observed, with 88% of the outbreaks reported between July and October. This seasonality was particularly clear for the small-scale establishments of fewer than 100 pigs, which accounted for most of the outbreaks notified in the EU (96%).
In wild boar, despite the introduction into new countries (Croatia, Greece and Sweden) and the spread in new areas of Italy, only a small increase (10%) in the number of notified outbreaks was observed in the EU in comparison with 2022, with considerable variations between countries. In 2023, ASF was notified in wild boar in 17 NUTS 3 regions that had never been affected before (compared with 14 regions in 2022), located in Croatia, Sweden, Italy, Germany, Greece, Poland and Slovakia. In the non-EU countries and territories, ASF was notified in wild boar in Bosnia and Herzegovina and in some new areas of north-west Serbia, with an increase in the number of notified outbreaks. Among Member States, Poland notified the largest number of ASF outbreaks in wild boar with 2686 outbreaks, representing 34% of the outbreaks in the EU. In the non-EU countries and territories, Serbia notified 213 outbreaks among wild boar, representing 70% of the outbreaks outside the EU.
Around 92% of the wild boar samples analysed were taken from hunted wild boar. Around 0.4% of them tested positive by PCR leading to the detection of 31% of the wild boar outbreaks. In contrast, samples taken from found-dead and road-killed wild boar accounted for 7.9% of the wild boar samples analysed. Around 31% of them tested positive by PCR leading to the detection of 69% of the wild boar outbreaks in the EU. A clear seasonality with winter/early spring peaks in the proportion of PCR-positive samples was observed in Poland, Slovakia and Hungary. However, no clear seasonal patterns could be observed in the other affected Member States. Seasonal patterns probably reflect a combination of ecological factors (e.g. seasonality in transmission rates or in carcass detection probability due to vegetation) and human factors (e.g. seasonality in carcass search effort and hunting intensity). In Germany and Hungary, a decreasing trend in both the proportion of PCR-positive samples from dead wild boar and the total number of notified outbreaks was observed. In Slovakia, a similar improvement was observed in the proportion of PCR-positive samples, but only since 2022.
Despite the introduction of ASF into previously unaffected countries and the increase in the number of outbreaks, particularly in domestic pigs, the restricted zones in the EU remained relatively stable. The total size of the restricted zones III, reflecting ASF in domestic pigs, was slightly reduced (−4%). This was influenced by the highly clustered outbreaks in Croatia, and the reduction of the restricted zone III in Poland, Slovakia and Bulgaria. The size of restricted zone II, reflecting ASF presence in wild boar, slightly increased in 2023 due to the new countries affected (Sweden, Croatia and Greece) and spread in previously affected ones (Italy, Slovakia and Lithuania), while it decreased in Hungary.
A decrease in the number of pig establishments, especially small establishments (< 100 pigs), was observed in Lithuania (−20%), Latvia (−17%) and Italy (−19%). In contrast, the number of small establishments increased in Romania (+27%), simultaneously with an increase in the incidence of ASF (from 0.1% to 0.2%) in comparison with 2022. The direct losses were highly concentrated in areas where the larger outbreaks were notified (e.g. the biggest outbreaks with more than 10,000 pigs were located in four regions of Romania).
In the Member States, the overall number of dead or killed wild boar positive to ASF notified to ADIS increased by 9% compared to 2022. However, there is considerable variation between countries. In Germany, this metric decreased by 44% between 2022 and 2023. In contrast, in Bulgaria, Poland and Italy, it increased by 73%, 60% and 290%, respectively. The analysis of the annual hunting bags at country level identified an increase in the wild boar population in the Baltic States, a decrease in Germany, Hungary, Romania, Poland and Slovakia, and a stable trend in Bulgaria. The decreasing trends in Romania, Hungary and Slovakia since the introduction of ASF follow a similar pattern observed in the Baltics in the first few years post-introduction.
...
https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2024.8809