Eradication of PRRS from Hungarian pig herds 2014–2022

Abstract

Background: Porcine reproductive and respiratory syndrome (PRRS) is an infectious disease with widespread distribution and is currently a major cause of economic loss in pig production. In Hungary, a National PRRS Eradication Program was introduced in order to reach a more efficient, economic and competitive international market position. The EU also approved the program, but the resultant legal obligations placed a burden on Hungarian producers in order to comply with EU competition rules. The veterinary authorities carried out the implementation of the program with the consent, continuous support and monitoring by the organizations of the pig industry as well as a scientific committee. The PRRS eradication program in Hungary was based on a regional territorial principle and was obligatory for every swine farm within those regions. In Hungary large fattening farms operate as all-in/all-out or continuous flow system. The large-scale breeding herds are predominantly farrow-to-finish types. Although its significance has decreased in recent decades, 20% of the Hungarian pig population is still kept in small-scale (backyard) farms (< 100 animals). Each PRRS-infected large-scale farm had to develop a unit-adapted eradication plan, including external and internal biosecurity measures, vaccinations, etc. It was crucial to render each fattening unit free of the disease since fattening units play a significant role in spreading the virus across the country. Eradication efforts mainly implemented depopulation-repopulation methods, with some farms using the test and removal method instead. Results: As the eradication progressed over the years, the introduction of infected fattening pigs was restricted. Because of these measures, by the end of 2018, Hungarian large-scale fattening farms became free of PRRS. The PRRS-free status of the small-scale herds was achieved by the end of 2015, and this status was maintained from 2016–2021. By the 31st of December in 2021, all breeding pigs at large scale-farms in Hungary had become free of wild type PRRS virus. By the 31st of March in 2022, the total pig population of the country, including all backyard farms and fattening units, had achieved PRRS-free status. Conclusions: The future goal is to secure and maintain the PRRS free status of Hungary by strict import regulations of live animals combined with continuous and thorough screening of incoming and resident herds for the presence of the virus.