WARSAW – Animal health officials in Poland confirmed African swine fever (ASF) outbreaks in three new provinces so far in 2021, according to a report from the Foreign Agricultural Service (FAS) of the US Department of Agriculture. Previous confirmed cases were mostly on farms in areas already listed as implementing special control measures for ASF.

In 2021 to date, three new provinces, Małopolskie, Łódzkie, and Świętokrzyskie, implemented ASF restrictions due to virus detections on hog farms. Veterinary authorities implemented all recommended protocols to contain and control the disease by establishing protection and surveillance zones around the farms and in the immediate area.

FAS said that from Jan. 1 to Oct. 29, Poland’s Chief Veterinary Officer (CVO) officially confirmed 119 ASF outbreaks on hog farms and 2,278 cases among wild boars — 69% of them in the western provinces bordering Germany.

Smallholder farms were affected the most, according to the report. The Veterinary Service noted that the factors increasing the risk of an outbreak included “keeping pigs in compact housing, ongoing intensive field work, and the increased movement of people,” according to the report.

The COV counted 55 outbreaks in the Podkarpackie and 18 in the Warmia-Mazury provinces in eastern Poland. Podkarpackie province in the south-east of Poland is characterized by small-scale farms. By the end of September, almost 7,000 animals were culled out of 44,000 animals kept in the Podkarpackie region to prevent the spread of ASF, according to the Regional Veterinary Officer in Krosno, Poland.

“As noted by the CVO, in 2021 the disease has affected mostly smallholder farms, which generally practice minimal biosecurity measures,” FAS said in its report. “As per official data, 57.1% of outbreaks in 2021 were noted on farms keeping up to 50 pigs, while big farms, with over 1,000 pigs, constitute only 5.9 percent of all outbreaks.

“In 2020, in comparison, 7.8 percent of ASF outbreaks were on farms keeping over 1,000 pigs,” the report said. “Additionally, in 2020, a total of almost 57,000 hogs were culled in 103 ASF outbreaks, while in 2021, to date, a total of over 41,500 hogs were culled in 119 ASF outbreaks.”

ASF cases in hogs usually increase during the summer months, but the CVO found that the virus has persisted longer on farms as significantly more cases have been confirmed in September and October, FAS said.

“The monthly ASF rate among wild boars also indicates a seasonal detection of the virus, with a peak in winter months, as opposed to ASF outbreaks on farms,” FAS noted. “In the first nine months of 2021, there were 31% less ASF cases in wild boars than in the same period of 2020.”

According to the CVO, intensive hunting and searches for corpses of wild boars in Poland were hampered last year due to COVID-19 restrictions, but the 2021 campaign was more successful. However, the wild boar population remains high and “intensive sanitary shootings” need to continue to gain control over the virus.