Détection d'Ascaris suum à l'abattoir par coprologie, sérologie et scoring des foies de porcs charcutiers plein air, bio ou élevés en bâtiment, engraissés en Wallonie | Detection of Ascaris suum in slaughtered pigs from Walloon indoor, outdoor or organic pig farms using coprology, serology and liver scoring

anglais. peer reviewed

anglais. From October to December 2019, Ascaris suum infections were detected in 55 indoor (32), organic (indoor with outdoor access) (18) or outdoor (5) pig herds in Wallonia, Belgium. Faeces and sera from up to 10 fattening pigs per farm were collected, and liver scoring was performed. Coprological examinations with the McMaster method were used to estimate the number of eggs per g of faeces (EPG) individually (n=450) and for up to 5 pooled samples (n=81). Serological analysis (n=518) using ELISA was performed. A total of 1583 livers were scored according to 4 scores: 0 (no milkspots), 1 (< 10 milkspots), 2 (≥ 10 milkspots) and 3 (most of the liver’s surface covered with milkspots). A telephone survey was performed with farmers concerned by the study. On 48% of the pig farms tested, Ascaris eggs were identified in faeces: 12 of 30 indoor pig farms tested (40%), 11 of 17 organic pig farms (65%) and 2 of 5 outdoor pig farms (40%). Serological analysis showed that 80% of the herds had been exposed to the parasite regardless of the type of herd. Indoors, 25% of herds had little or no infection, 25% had a moderate infection level and 50% had a high infection level. In organic herds, the percentages of these three levels were 17%, 28% and 55%, respectively. On outdoor pig farms, the 5 herds tested had a high infection level. According to liver scoring, 96% of pig herds tested had liver lesions, but the score was 1 for 40% of the herds tested. These results and the response to the survey will allow for more specific strategies to counter A. suum infestations.