title: Changes in the risk management of Salmonella enterica subspecies diarizonae serovar 61:(k):1, 5, (7) in Swedish sheep herds and sheep meat due to the results of a prevalence study 2012.
abstract: BACKGROUND
  The prevalence of Salmonella in food producing animals is very low in Sweden due to rigorous control programmes. However, no active surveillance is in place in sheep. The authorities decided to perform a prevalence study in sheep herds because findings at slaughter indicated that sheep associated S. diarizonae (S. enterica subspecies diarizonae serovar 61:(k):1, 5, (7)) might be common in sheep. Sampling was stratified by herd size in two groups, small herds with ≤ 30 animals and large herds with > 30 animals. In each stratum, 237 herds were selected at random. Faecal samples received from 244 out of the 474 randomly selected herds were analysed.
  
  
  RESULTS
  A total of 40 of 100 (40%) of large herds and 17 of 144 (12%) of small herds were positive. The overall adjusted prevalence was 17.6% (95% CI, 12.9-22.2). Sheep associated S. diarizonae was detected in all counties (n = 21). Scientific opinions and an evaluation of on-farm control measures performed concluded that the impact of sheep associated S. diarizonae on human health is very low, and that risk management measures applied in response to findings of sheep associated S. diarizonae in sheep or sheep meat can be expected to have very little impact on reducing risks to human health. As a result, Swedish authorities decided to make an exemption for sheep associated Salmonella diarizonae in sheep and sheep meat in the current Salmonella control measures.
  
  
  CONCLUSIONS
  Sheep associated S. diarizonae is endemic in Swedish sheep herds. It is more common in large herds and not limited to certain parts of the country. The responsible authorities concluded that current risk management actions regarding sheep associated S. diarizonae in sheep and sheep meat are not proportional to the risk. This is the first time in the history of the Swedish Salmonella control programme that an exemption from the legislation has been made for a specific serovar. If there is any future indication of an increasing risk, due to e.g. change in the pathogenicity or development of antimicrobial resistance, the risk assessment will be re-evaluated and control measures reinforced if needed.
authors: National Veterinary Institute, SE-751 89, Uppsala, Sweden. kaisa.soren@sva.se.
authors: Kaisa
authors: K
authors: Sörén
authors: National Food Agency, P.O. Box 622, SE-751 26, Uppsala, Sweden. mats.lindblad@slv.se.
authors: Mats
authors: M
authors: Lindblad
authors: The Public Health Agency of Sweden (previously the Swedish Institute for Communicable Disease Control), SE-171 82, Solna, Sweden. cecilia.jernberg@folkhalsomyndigheten.se.
authors: Cecilia
authors: C
authors: Jernberg
authors: National Veterinary Institute, SE-751 89, Uppsala, Sweden. erik.eriksson@sva.se.
authors: Erik
authors: E
authors: Eriksson
authors: National Veterinary Institute, SE-751 89, Uppsala, Sweden. lennart.melin@sva.se.
authors: Lennart
authors: L
authors: Melin
authors: National Veterinary Institute, SE-751 89, Uppsala, Sweden. helene.wahlstrom@sva.se.
authors: Helene
authors: H
authors: Wahlström
authors: The Swedish Board of Agriculture, SE-551 82, Jönköping, Sweden. maria.lundh@jordbruksverket.se.
authors: Maria
authors: M
authors: Lundh
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D015995:Prevalence; D012308:Risk Management; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D019779:Salmonella enterica / Q000502:physiology*; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D013548:Sweden / Q000453:epidemiology
references: Int J Food Microbiol. 2004 Apr 1;92(1):45-53
references: 15033267
references: J Vet Diagn Invest. 2007 Mar;19(2):194-7
references: 17402617
references: Int J Food Microbiol. 2000 Jun 30;58(1-2):49-58
references: 10898461
references: J Hyg (Lond). 1966 Sep;64(3):271-4
references: 5223430
references: J Comp Pathol. 2012 Nov;147(4):406-9
references: 22572396
references: Can Vet J. 1990 Jan;31(1):42
references: 17423497
references: Prev Vet Med. 2002 Jan 22;52(3-4):267-75
references: 11849721
references: Vet Rec. 2001 Nov 3;149(18):555-7
references: 11720209
references: Epidemiol Infect. 2004 Apr;132(2):253-61
references: 15061500
references: J Clin Microbiol. 1986 Jun;23(6):1056-64
references: 3711296
references: Prev Vet Med. 2002 Jan 22;52(3-4):277-85
references: 11849722
references: Epidemiol Infect. 1992 Feb;108(1):59-65
references: 1547841