Analysis of the baseline survey on the prevalence of Salmonella in holdings with breeding pigs, in the EU, 2008 - Part B: factors associated with Salmonella pen positivity


European Food Safety Authority
EFSA Journal
EFSA Journal 2011;9(7):2329 [159 pp.].

EFSA wishes to thank the members of the Task Force on Zoonoses Data Collection: Marta Bedriova, Susan Chircop, Georgi Chobanov, Veronica Cibin, Jürg Danuser, Kris De Smet, Kostantins Golubevs, Matthias Hartung, Birgitte Helwigh, Merete Hofshagen, Simona Iannetti, Sarolta Idei, Patrícia Inácio, Elina Lahti, Lesley Larkin, Emma Martín Denia, Peter Much, Edith Nagy, Ioana Neghirla, Lisa O’Connor, Jacek Osek, Manca Pavšič, Christodoulos Pipis, Saara Raulo, Jose Luis Saez Llorente, Julien Santolini, Petr Šatrán, Snieguole Sceponaviciene, Joseph Schon, Richard Smith, Jelena Sõgel, Johanna Takkinen, Chris Teale, Kilian Unger, Rob Van Oosterom, Luc Vanholme, Dimitris Vourvidis for the endorsement of the report; the members of the working group: Vojislava Bole-Hribovšek, Mariann Chriél, Rob Davies, June Fanning, Arjen W. van de Giessen, Laura Pérez Palancar, Antonia Ricci, Nicolas Rose, Lucy Snow for the preparation of this EFSA scientific output; Arjan Stegeman for the peer review; the EFSA’s contractors: Hendriek Boshuizen and Gerda Doornbos from National Institute for Public Health and Environment (RIVM), Tine Hald from Danish Technical University, National Food Institute, Elinor Jones, Mark Arnold and Alasdair Cook from the Veterinary Laboratories Agency (VLA), and the EFSA’s staff members: Giusi Amore, Francesca Riolo, José Cortinas Abrahantes and Frank Boelaert for the support provided to this EFSA scientific output.

Scientific Report of EFSA
On request from
European Commission
Question Number
25 May 2011
Published in the EFSA Journal
26 July 2011
European Food Safety Authority (EFSA) Parma Italy

A European Union-wide Salmonella baseline survey was conducted in 2008 in holdings with breeding pigs. A total of 1,609 randomly selected holdings housing and selling mainly breeding pigs (breeding holdings) and 3,508 holdings housing commercial breeding pigs and mainly selling pigs for fattening or slaughter (production holdings) were sampled. In each selected holding, pooled fresh faecal samples were collected from 10 randomly chosen pens of breeding pigs over six months of age, representing the different stages of the breeding herd, and examined for the presence of Salmonella. Analyses at country-level demonstrated a strong positive association between the prevalence of Salmonella-positive breeding holdings and the prevalence of Salmonella-positive production holdings, suggesting a vertical dissemination of Salmonella between the holdings. Based on the combined results from breeding and production holdings, multivariable regression analysis showed that the odds of Salmonella-positive pens with pigs increased with the number of breeding pigs in the holding and with the following pen-level factors: flooring systems other than slatted floors or solid floors with straw, presence of maiden gilts, number of pigs per pen, feed of commercial compound origin or pelleted feed. A tendency towards some Member State group-specific Salmonella serovars was identified, but spatial distribution of other serovars was heterogeneous. S. Typhimurium and S. Derby were widespread and dominant in the EU, in both breeding and production holdings. However, many other serovars were relatively prevalent in Western EU Member States. A complementary within-holding prevalence study indicated that, due to a non-perfect diagnostic test sensitivity, the observed EU-level prevalence of Salmonella-positive holdings with breeding pigs was roughly 80% of the estimated true EU-level prevalence. But this proportion varied between Member States.

Salmonella, pigs, breeding pigs, baseline survey, risk factors, EU
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