Frieda Jorgensen and Caroline Willis, writing for the UK Society for Applied Microbiology, say that poultry and poultry products are recognized as the most significant source of human Campylobacter and Salmonella infections in the developed world, including the UK. Outbreak investigations and case-control studies investigating risk-factors and transmission routes have identified poultry meat and eggs as major sources of infection. However, non-foodborne routes such as animal contact, and occupational or recreational exposure, are also important.

Poultry meat, and chicken liver or duck liver products were implicated as the source in 62 of 103 Campylobacter outbreaks reported to the Health Protection Agency (HPA) between 2000 and 2012. Eggs and poultry meat were implicated in 52 and 43 Salmonella outbreaks (of 382 in total reported to the HPA), respectively, over the same time period. In the EU, eggs and egg products were one of the main food vehicles associated with foodborne outbreaks, while broiler meat was the fifth most frequent cause of foodborne Salmonella outbreaks in 2008 (EFSA, 2010a). Moreover, data from the European Commission’s Rapid Alert System for Food and Feed (2008) indicated that reports of microbiological contamination in poultry meat were more common than for any other food type. In an EU survey from 2008, raw chicken meat was frequently contaminated with campylobacters (approximately 80% of samples) but less so with salmonellas (approximately 16%) (EFSA, 2010b).

The extent to which different infection risk factors are associated with different sources can be inferred by combining case-control studies with source attribution studies (i.e., studies that determine the predisposition of specific genotypes to infect particular animals). Such studies have provided further evidence that poultry is the major source of campylobacteriosis.