Eight years of African swine fever in Poland

Abstract

African swine fever (ASF) was detected in Poland on February 17, 2014. Epidemiological studies from other European countries and the results of epidemiological investigations in different regions of Poland in which the disease was detected indicate that the African swine fever virus (ASFV) must have been present in Poland for at least a few months before the first ASF outbreak was detected. The ASFV virus was introduced into the territory of the Republic of Poland from the Republic of Belarus. During the 8 years of the ASF epizootic in Poland, multidisciplinary measures were taken to eradicate the disease from the wild boar population and limit the possibility of virus transmission from the wild boar habitat to pig farms. Despite the various attempts to stop the expansion of ASF, we have not been successful in eradicating the disease in Poland. By the end of March, 2022, a total of 14016 ASF outbreaks were found in the wild boar population and 488 in the pig population. Throughout the 8-year ASF epidemic in Poland and other countries of Central and Eastern Europe, the course of the disease in the wild boar population, and consequently in pigs, differed significantly from that observed in the 1960s, 70s, 80s, and 90s in Portugal and Spain. First of all, according to predictions by experts from countries previously affected by ASF, the emergence of the disease in the wild boar population in Eastern Europe was supposed to result in the disease becoming spontaneously extinct in the wild boar population because of its mortality rate amounting to almost 100% and the high virulence of ASFV. However, these predictions have not materialized. The possible development of the epizootic situation in Eastern Europe was similarly underestimated. Experts expected a course of ASF similar to that of classical swine fever (CSF) in the wild boar population in Europe in the 1990s and at the beginning of the 21st century. Unfortunately, observations made so far in Poland, the Baltic countries, and southern Europe show that most assumptions regarding the dynamics of ASF spread were inaccurate. Actions aimed at limiting the circulation and spread of ASFV in the wild boar population in Poland proved to be insufficient. The regulations, and above all their implementation and enforcement, were ineffective. Consequently, during the period analyzed (February 2014 – end of March 2022), the disease spread to 11 out of 16 voivodeships in the case of pigs and to 11 voivodeships, though not exactly the same, in the case of wild boar. In principle, the number of ASF outbreaks in the pig and wild boar populations increased year by year. It can be concluded that since the appearance of the first case of ASF the chances of eradicating the disease in Poland have been continuously diminishing. It seems that the situation may improve only if there is a fundamental change in the approach to controlling ASF. This should include radical measures against producers who do not comply with the established principles of biosecurity and a significant change in the strategy of controlling ASF in the wild boar population with a more active involvement on the part of hunters, foresters, veterinary inspectors, police, and farmers themselves.