Review article Campylobacters as zoonotic pathogens: A food production perspective Tom Humphrey a, ⁎ , Sarah O'Brien b , Mogens Madsen c a University of Bristol, Division of Veterinary Pathology, Infection & Immunity, School of Clinical Veterinary Sciences, The Churchill Building, Langford, Bristol BS40 5DU, United Kingdom b University of Manchester, Hope Clinical Academic Group, Clinical Sciences Building, Hope Hospital, Stott Lane, Salford M6 8HD, United Kingdom c Dianova, Brendstrupgaardsvej 102, Aarhus N, Denmark Received 7 December 2006 Abstract Campylobacters remain highly important zoonotic pathogens worldwide which infect an estimated 1% of the population of Western Europe each year. Certain campylobacters are also important in infections of animals, particularly of the reproductive tract, and some are involved in periodontal disease. This paper focuses, however, on the two species which are most important in food-borne infections of humans, Campylo- bacter (C.) jejuni and C. coli. Infection with these campylobacters is serious in its own right but can also have long-term sequelae such as reactive arthritis and Guillain–Barré syndrome. The pathogens are ubiquitous in nature and in domestic animals and, as a consequence, are found frequently in the environment and on many raw foods, of both plant and animal origin and bacterial numbers can be very high on certain key foods like raw poultry meat. Although all commercial poultry species can carry campylobacters, the risk is greater from chicken because of the high levels of consumption. Campylobacters are relatively ‘new’ zoonotic pathogens as routine culture from clinical specimens only became possible in the late 1970s. As a consequence there is much that still needs to be understood about the behaviour and pathogenicity of these highly important bacteria. In particular, and from a food industry/food safety perspective, it is important to better understand the behaviour of C. jejuni and C. coli in the food production environment, and how this affects their ability to survive certain food production processes. There is a belief that campylobacters are much more sensitive to hostile conditions than either salmonellas or Escherichia coli. Much of data to support this view have been derived from laboratory experiments and may not fully represent the natural situation. Studies are showing that campylobacters may be more robust than previously thought and thus may represent a greater challenge to food safety. We recommend that research is undertaken to better understand how campylobacters behave in the food chain and how responses to relevant conditions affect their ability to survive processing and their virulence. There is also a need to better understand the reasons why campylobacters are capable of frequent change, particularly in the expression of surface antigens. © 2007 ILSI Europe. Published by Elsevier B.V. All rights reserved. Keywords: Campylobacters; Zoonotic pathogens; Food production Contents 1. Introduction .............................................................. 238 1.1. Campylobacters ........................................................ 238 1.2. Disease incidence and clinical symptoms in humans ..................................... 239 2. Epidemiology of campylobacter infections in humans ........................................ 240 2.1. Disease burden ........................................................ 240 2.2. Range and severity of symptoms and chronic effects ..................................... 240 2.3. Disease trends ......................................................... 241 International Journal of Food Microbiology 117 (2007) 237 – 257 www.elsevier.com/locate/ijfoodmicro ⁎ Corresponding author. ILSI Europe, 83 Avenue E. Mounier, Box 6, BE-1200 Brussels, Belgium. Tel.: +32 2 771 00 14; fax: +32 2 762 00 44. E-mail address: publications@ilsieurope.be (T. Humphrey). 0168-1605/$ - see front matter. © 2007 ILSI Europe. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.ijfoodmicro.2007.01.006