The outbreak of Salmonella Heidelberg infection linked to Foster Farms brand chicken in the USA has claimed at least 317 victims across 20 states at the last count. Most of those victims live in California, where the chicken was processed, but the state Department of Health has said that a recall is not necessary because proper handling and preparation of raw chicken – in other words cooking it thoroughly and washing your hands – makes it safe for consumption. Meanwhile the Food Safety and Inspection Service (FSIS) has given the go-ahead for Foster Farms to continue production at three processing plants that have been linked to the outbreak after receiving assurances that new and improved food safety measures are being introduced to reduce Salmonella contamination rates.
It is an unfortunate fact that many unprocessed foods have the potential to be contaminated with foodborne pathogens like Salmonella, E. coli, or Listeria. These bacteria are widespread in the environment and often come into contact with the plants and animals that we farm for food. Salmonella has evolved in the guts of animals, including humans, and some strains are well adapted to thrive in poultry. If cross contamination during slaughtering and processing occurs as well, the eventual contamination rate of chicken on sale to the consumer can be very high. This seems to be what has happened at Foster farms. The FSIS sets an acceptable number of carcases positive for Salmonella at 7.5%, but reports indicate that the three Foster farms plants concerned had rates nearer 25% – hence the request to improve processing hygiene.
A lot can be done to reduce Salmonella prevalence in poultry, both on the farm and during processing. Vaccination and good biosecurity can help prevent flocks becoming infected in the first place, while effective cleaning and hygienic operation of slaughtering and processing equipment can cut cross-contamination rates dramatically. But is it reasonable for consumers to expect Salmonella-free chicken? The Danish poultry industry has shown that is feasible, but it isn’t cheap and it is only really possible for flocks kept in closed sheds. Shouldn’t consumers also be aware of how to handle potentially contaminated food safely? Ordinarily I would say that we should all take some responsibility for our own food safety, but a feature of the Foster Farms outbreak calls for a different view. The outbreak Salmonella strains found are all resistant to more than one antibiotic. That may explain why an unusually high proportion (42%) of the people made ill needed to go to hospital. Antibiotic resistance is becoming more and more common and makes foodborne pathogens more dangerous. That additional risk adds weight to the argument that poultry producers and processors should indeed be aiming for Salmonella-free chicken. After all, the USA already adopts a zero-tolerance approach for hazardous foodborne pathogens like E. coli O157:H7.