title: Hospital-acquired listeriosis associated with sandwiches in the UK: a cause for concern.
abstract: BACKGROUND
  Hospital-acquired outbreaks of listeriosis are not commonly reported but remain a significant public health problem.
  
  
  OBJECTIVE
  To raise awareness of listeriosis outbreaks that have occurred in hospitals and describe actions that can be taken to minimize the risk of foodborne listeriosis to vulnerable patients.
  
  
  METHODS
  Foodborne outbreaks and incidents of Listeria monocytogenes reported to the Health Protection Agency national surveillance systems were investigated and those linked to hospitals were extracted. The data were analysed to identify the outbreak/incident setting, the food vehicle, outbreak contributory factors and origin of problem.
  
  
  RESULTS
  Most (8/11, 73%) foodborne outbreaks of listeriosis that occurred in the UK between 1999 and 2011 were associated with sandwiches purchased from or provided in hospitals. Recurrently in the outbreaks the infecting subtype of L. monocytogenes was detected in supplied prepacked sandwiches and sandwich manufacturing environments. In five of the outbreaks breaches in cold chain controls of food also occurred at hospital level.
  
  
  CONCLUSIONS
  The outbreaks highlight the potential for sandwiches contaminated with L. monocytogenes to cause severe infection in vulnerable people. Control of L. monocytogenes in sandwich manufacturing and within hospitals is essential to minimize the potential for consumption of this bacterium at levels hazardous to health. Manufacturers supplying sandwiches to hospitals should aim to ensure absence of L. monocytogenes in sandwiches at the point of production and hospital-documented food safety management systems should ensure the integrity of the food cold chain.
authors.affiliation: Department of Gastrointestinal, Emerging and Zoonotic Infections, Health Protection Agency, Health Protection Services, London, UK. clittle200@gmail.com
authors.forename: C L
authors.initials: CL
authors.lastname: Little
authors.forename: C F L
authors.initials: CF
authors.lastname: Amar
authors.forename: A
authors.initials: A
authors.lastname: Awofisayo
authors.forename: K A
authors.initials: KA
authors.lastname: Grant
mesh_terms: D000368:Aged; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D005516:Food Microbiology; D005525:Food-Processing Industry / Q000379:methods; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D017053:Infection Control / Q000379:methods; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D008088:Listeriosis / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D011247:Pregnancy; D012034:Refrigeration / Q000379:methods / Q000592:standards; D006113:United Kingdom / Q000453:epidemiology