Preventive Veterinary Medicine 116 (2014) 193–196 Contents lists available at ScienceDirect Preventive Veterinary Medicine j ourna l h om epa ge: www.elsevier.com/locate/prevetmed Short Communication Seroprevalence of enteropathogenic Yersinia spp. in pig batches at slaughter Gerty Vanantwerpen ∗ , Inge Van Damme, Lieven De Zutter, Kurt Houf Department of Veterinary Public Health and Food Safety, Faculty Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium a r t i c l e i n f o Article history: Received 13 December 2013 Received in revised form 10 May 2014 Accepted 26 May 2014 Keywords: Yersinia spp. Seroprevalence Pig Batch Slaughter a b s t r a c t Enteropathogenic Yersinia spp. are one of the main causes of foodborne bacterial infections in Europe. Slaughter pigs are the main reservoir and carcasses are contaminated during a sub-optimal hygienically slaughtering-process. Serology is potentially an easy option to test for the Yersinia-status of the pig (batches) before slaughter. A study of the variation in activity values (OD%) of Yersinia spp. in pigs and pig batches when applying a serological test were therefore conducted. In this study, pieces of the diaphragm of 7047 pigs, originating from 100 farms, were col- lected and meat juice was gathered, where after an enzyme-linked immunosorbent assay (ELISA) Pigtype Yopscreen (Labor Diagnostik Leipzig, Qiagen, Leipzig, Germany) was per- formed. The results were defined positive if the activity values exceeded the proposed cut-off value of 30 OD%. Results at pig level displayed a bimodal-shaped distribution with modes at 0–10% (n = 879) and 50–60% (n = 667). The average OD% was 51% and 66% of the animals tested positive. The within-batch seroprevalence ranged from 0 to 100% and also showed a bimodal distribution with modes at 0% (n = 7) and 85–90% (n = 16). On 7 farms, no single seropositive animal was present and in 22 farms, the mean OD% was below 30%. Based on the results obtained at slaughter, 66% of the pigs had contact with enteropathogenic Yersinia spp. at farm level. The latter occurred in at least 93% of the farms indicating that most farms are harboring enteropathogenic Yersinia spp. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Enteropathogenic Yersinia spp. are an important cause of foodborne bacterial infections in Europe. Two species, human pathogenic Yersinia enterocolitica and Y. pseudotuberculosis, caused 7017 infections or 1.63 infec- tions/100,000 inhabitants in 2011 in Europe, with human pathogenic Y. enterocolitica responsible for more than 98% ∗ Corresponding author. Tel.: +32 9 264 73 42. E-mail addresses: Gerty.Vanantwerpen@ugent.be (G. Vanantwerpen), Inge.Vandamme@ugent.be (I. Van Damme), Lieven.Dezutter@ugent.be (L. De Zutter), Kurt.Houf@ugent.be (K. Houf). of these infections (European Food Safety Authority (EFSA), 2013). Symptoms range from mild, self-limiting diarrhea to mesenteric lymphadenitis. However, other chronic disor- ders like reactive arthritis or erythema nodosum can also emerge (Bottone, 1997; EFSA, 2013). Many animal species may be carrier of these pathogens, but pigs are regarded as the main reservoir. Handling and consumption of raw or undercooked pork are the primary risk factors for human infection (Tauxe et al., 1987; Nikolova et al., 2001; Boqvist et al., 2009; EFSA, 2013). Yersinia strains harboring the virulence plasmid (pYV) are pathogenic for humans. Strains lacking the pYV like Y. enterocolitica biotype 1A are considered apathogenic (Revell and Miller, 2001). Pathogenic strains trigger an http://dx.doi.org/10.1016/j.prevetmed.2014.05.011 0167-5877/© 2014 Elsevier B.V. All rights reserved.