PigProgress reports that the number of African Swine Fever (ASF) outbreaks among domestic pigs in the EU last year was five times higher than in 2022, reaching a magnitude similar to that of 2019.

Croatia and Romania are the major "performers"

This was mainly driven by the introduction and subsequent spread of ASF in Croatia, where 1,124 cases were reported, and its reappearance in Romania with 736 cases. These two countries together account for 96% of the outbreaks in the EU.

In the rest of the EU, outbreaks among domestic pigs were sporadic, with 30 in Poland, 16 in Italy, and less than 10 in the other 6 affected member states.

Furthermore, almost 7,800 known cases were reported in wild boars, with Poland leading the list with 2,686 cases, while Italy reported 1,051 infected wild boars.

ASF in 14 EU member states

This emerges from the annual ASF report of the European Food Safety Authority EFSA. In 2023, ASF affected 14 member states, including Croatia and Sweden. ASF reappeared in Greece after the country had been disease-free since 2021.

Most ASF outbreaks among domestic pigs were detected through clinical suspicion (94%), followed by tracing from affected units (3%), and weekly testing of at least 2 dead pigs in units (3%).

No outbreaks were detected through active surveillance targeting healthy pigs at slaughter, before movement, or randomly selected in units.

Seasonal outbreaks

At the EU level, ASF in domestic pigs was notified in 11 regions that had never been affected before, compared to 5 in 2022, located in Croatia, Greece, Germany, Italy, and Poland, indicating a broader spread into new areas.

The majority of outbreaks (96%) occurred on small units with fewer than 100 pigs, and the 6 outbreaks that occurred on units with over 10,000 pigs were all in Romania. Additionally, ASF outbreaks in domestic pigs were clearly seasonal in all countries, with 88% of outbreaks reported between July and October.

ASF in wild boars

In wild boars, despite the introduction into new countries (Croatia, Greece, and Sweden) and spread into new areas of Italy, only a small increase (10%) in the number of reported outbreaks was observed in the EU compared to 2022, with considerable variations between countries.

A winter peak was observed only in Poland, Slovakia, and Hungary. The epidemiological situation in wild boars improved in Germany and Hungary, as suggested by the decrease in the number of outbreaks and the proportions of PCR-positive samples from dead wild boars.

Overall, 31% of wild boar carcasses found during passive surveillance tested positive by PCR, representing 69% of ASF outbreaks in wild boars in the EU. In contrast, 0.4% of hunted wild boars tested positive, representing 31% of outbreaks.

Despite the introduction of ASF into new countries and the increase in the number of outbreaks, the size of restriction zones in the EU remained stable, due to heavily clustered outbreaks in Croatia and reductions in restriction zones in Poland, Slovakia, and Bulgaria (in domestic pigs) and Hungary (in wild boars). (Photo: Dreamstime)