Epidemiology and Infection

Original Papers

Salmonella

International outbreak investigation of Salmonella Heidelberg associated with in-flight catering

J. REBOLLEDOa1a2 c1, P. GARVEYa2, A. RYANa3, J. O'DONNELLa2, M. CORMICANa4, S. JACKSONa2, F. CLOAKa2, L. CULLENa3, C. M. SWAANa5, B. SCHIMMERa5, R. W. APPELSa6, K. NYGARDa7, R. FINLEYa8, N. SREENIVASANa9, A. LENGLETa10, C. GOSSNERa10 and P. McKEOWNa2

a1 European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden

a2 Health Protection Surveillance Centre, Dublin, Ireland

a3 Department of Public Health Medicine, HSE-West (Northwest), Ireland

a4 National Salmonella Shigella and Listeria Reference Laboratory, Galway, Ireland

a5 Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands

a6 Infectious Disease Control, Public Health Service Kennemerland, Schippol, The Netherlands

a7 Norwegian Institute of Public Health, Oslo, Norway

a8 Centre for Food-borne, Environmental and Zoonotic Infectious Diseases, Public Health Agency of Canada, Guelph, Canada

a9 Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA

a10 Surveillance and Response Support Unit, European Centre for Disease Prevention and Control, Stockholm, Sweden

SUMMARY

Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10·2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations.

(Received August 22 2012)

(Revised April 13 2013)

(Accepted July 03 2013)

(Online publication July 26 2013)

Key words

  • Aircraft;
  • food poisoning;
  • in-flight catering;
  • international travel;
  • Salmonella

Correspondence

c1 Author for correspondence: Miss J. Rebolledo, Health Protection Surveillance Centre – VPD, 25–27 Middle Gardiner Street, Dublin 1, Ireland. (Email: javierarebolledo@gmail.com)

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