African Swine Fever Outbreak Investigation on Large Commercial Pig Farm in Serbia

Abstract

The fi rst confi rmed case of African Swine Fever (ASF) in Serbia occurred in 2019. Since then, numerous outbreaks in domestic pigs and wild boars have been reported. Until April 2021, all the detected ASF cases were in backyard pigs. Beside backyard and smallholders farming systems as a dominant pig production system in Serbia, large commercial pig farms can also be found, located mostly in villages. In the beginning of April 2021, a large commercial farrow-to-fi nish pig farm in Serbia with almost 19,000 animals was affected with the ASF virus. The pig farm analysed in this paper is located in an area where ASF was confi rmed earlier in both backyard and wild boars. In this study, we describe the overall epidemiological course of the ASF outbreak. Epidemiological investigation using a hypothesis-based approach was conducted in order to reconstruct the disease course until the offi cial notifi cation. All the available data from the farm were analysed with the aim to determine the high-risk period (HRP). Some of the key points to consider when it comes to the sources of infection and entry route of ASF are the following: contamination of the area in the immediate vicinity of the farm, risky human activities, irregularities and some omissions in the external farm biosecurity and immediate proximity of the city waste-yard where the communal waste is disposed of. It was concluded that when commercial pig farms are surrounded by villages with a large number of backyards, hence the anthropogenic factor is the key risk factor for ASF spreading

Prvi slučaj afričke kuge svinja (AKS) u Srbiji je dijagnostikovan 2019. godine. Od tada, beleži se pojava bolesti u populaciji domać ih i divljih svinja. Sve do aprila 2021. godine žarišta AKS su bila lokalizovana u populaciji domaćih svinja u seoskim dvorištima. Pored seoskih gazdinstava i porodičnih farmi kao dominantnog načina proizvodnje, u Srbiji se nalaze i velike komercijalne farme svinja, uglavnom oko seoskih naselja. Početkom aprila 2021. godine, u komercijalnoj farma svinja, proizvodnog kapaciteta oko 19000 jedinki, potvrdjena je infekcija virusom AKS. U radu je sa epizootiološkog aspekta, hronološki opisan tok infekcije AKS. Epizootiološko istraživanje je zasnovano na hipotezama u cilju utvrdjivanja potencijalnih puteva unošenja AKS. Analizirani su dostupni farmski podaci kako bi se utvrdio vremenski period visokog rizika (HRP). Farma svinja se nalazi u području gde je u prethodnom periodu potvrđena AKS u seoskim gazdinstvima, kao i u populaciji divljih svinja. Kontaminacija ambijenta u neposrednoj blizini farme, visoko rizične aktivnosti humane populacije u okruženju (brojna seoska gazdinstva), postojanje pojedinih aktivnosti visokog rizika u realizaciji eksterne biosigurnosti i neposredna blizina gradske deponije gde se odlaže komunalni otpad, su svakako ključni momenti kada se razmatraju izvori infekcije i put unošenja AKS. Zaključeno je da u uslovima kada su komercijalne farme okružene selima, u kojima su dominira uzgoj domaćih svinja u seoskim dvorištima, ljudske aktivnosti predstavljaju ključni faktor rizika za širenje AKS.