A long-lasting outbreak of Salmonella Typhimurium U323 associated with several pork products, Denmark, 2010.
This paper shows that control of foodborne disease outbreaks may be challenging even after establishing the source of infection. An outbreak of Salmonella Typhimurium U323 infections occurred in Denmark from March to September 2010, involving 172 cases. Before the detection of human cases, several positive isolates of the outbreak strain had been found in a particular pig slaughterhouse and thus early traceback, investigation and control measures were possible. Several batches of pork and pork products were recalled and the slaughterhouse was closed twice for disinfection. No single common food item was identified as the outbreak source, but repeated isolation of the outbreak strain from the slaughterhouse environment and in pork and products as well as patient interviews strongly suggested different pork products as the source of infection. Furthermore, a matched case-control study identified a specific ready-to-eat spreadable pork sausage (teewurst) as the source of a sub-outbreak (matched odds ratio 17, 95% confidence interval 2·1-130).
Department of Epidemiology, Statens Serum Institut, Copenhagen, Denmark.
K G
KG
Kuhn
Department of Microbiology and Risk Assessment, National Food Institute, Technical University of Denmark, Copenhagen, Denmark.
G
G
Sørensen
Department of Microbiology Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark.
M
M
Torpdahl
Department of Microbiology Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark.
M K
MK
Kjeldsen
Danish Veterinary and Food Administration, Copenhagen, Denmark.
T
T
Jensen
Department of Epidemiology, Statens Serum Institut, Copenhagen, Denmark.
S
S
Gubbels
Danish Veterinary and Food Administration, Copenhagen, Denmark.
G O
GO
Bjerager
Department of Microbiology and Risk Assessment, National Food Institute, Technical University of Denmark, Copenhagen, Denmark.
A
A
Wingstrand
Department of Microbiology and Risk Assessment, National Food Institute, Technical University of Denmark, Copenhagen, Denmark.
L J
LJ
Porsbo
Department of Epidemiology, Statens Serum Institut, Copenhagen, Denmark.
S
S
Ethelberg
D000003:Abattoirs / Q000592:standards; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001434:Bacteriophage Typing; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005506:Food Contamination / Q000032:analysis* / Q000517:prevention & control; D005517:Foodborne Diseases; D006801:Humans; D007223:Infant; D008297:Male; D008461:Meat Products / Q000506:poisoning*; D008875:Middle Aged; D018598:Minisatellite Repeats; D012044:Regression Analysis; D012478:Salmonella Food Poisoning / Q000453:epidemiology*; D012486:Salmonella typhimurium / Q000302:isolation & purification*; D013552:Swine