Watch What You Eat: A Groundbreaking Report on Food-Pathogen Combinations


Four months after President Obama signed the Food Safety Modernization Act (FSMA), a groundbreaking report from the Emerging Pathogens Institute (EPI) has highlighted the ten food-pathogen combinations that are the greatest burden on public health.

The FSMA, signed into law on Jan. 4, is a significant step toward implementing a proactive, public health-oriented food safety agenda, which the Obama administration laid out in July 2009. The FSMA expands the Food and Drug Administration's (FDA) regulatory authority by allowing it to order recalls of contaminated foods and requiring it to increase the number of inspections it conducts at high-risk food facilities.

The FSMA was drafted in response to concern about the prevalence of foodborne illness in the United States. According to figures from the Centers for Disease Control and Prevention (CDC), one in six Americans is sickened by foodborne illnesses each year. While most of these illnesses are mild, more than 100,000 Americans are hospitalized and 3,000 die as a result. Although this is an obvious area of concern for FDA and the Food Safety and Inspection Service (FSIS), the two regulatory agencies with the primary responsibility for guaranteeing our foods are safe, they are left with relatively little actionable information: the CDC tracks foodborne illness by pathogen but does not link the data to specific foods.

Researchers at EPI found that more than 95 percent of the annual illnesses and nearly 98 percent of the deaths can be attributed to only fourteen pathogens (disease-causing agents, such as bacteria, viruses, or other microorganisms). Because the impact of the different pathogens can be difficult to compare (e.g., the public health burden of a very rare but often deadly pathogen versus one that is more common but milder), the researchers set out two standard indexes of the burden posed by these top fourteen pathogens: monetary cost of the illness and the loss of Quality Adjusted Life Years (QALYs), a public health measurement of the discomfort and temporary or permanent disabilities caused by an illness. (One year of perfect health equals one QALY.)

By comparing this impact data to expert studies and records of foodborne illness outbreaks over the past eleven years, they produced the first-ever list of the ten food-pathogen combinations with the greatest cost to public health:

  • Campylobacter in poultry, which costs $1.3 billion and causes a loss of 9,500 QALYs
  • Toxoplasma in pork, which costs $1.2 billion and causes a loss of 4,500 QALYs
  • Listeria in deli meats, which costs $1.1 billion and causes a loss of 4,000 QALYs
  • Salmonella in poultry, which costs $700 million and causes a loss of 3,600 QALYs
  • Listeria in dairy products, which costs $700 million and causes a loss of 2,600 QALYs
  • Salmonella in complex (multi-ingredient) foods, which costs $600 million and causes a loss of 3,200 QALYs
  • Norovirus in complex foods, which costs $900 million and causes a loss of 2,300 QALYs
  • Salmonella in produce, which costs $500 million and causes a loss of 2,800 QALYs
  • Toxoplasma in beef, which costs $700 million and causes a loss of 2,500 QALYs
  • Salmonella in eggs, which costs $400 million and causes a loss of 1,900 QALYs

This ranking suggests obvious targets for reducing the incidence and impact of foodborne illness. While several of these pathogens are familiar, some of the conclusions suggested by the report are surprising:

  • Foodborne pathogens are equally likely to be found in foods regulated by the FDA or FSIS. The EPI report suggests that diseases caused by contaminated poultry, pork, and beef – primarily regulated by FSIS – costs about $5.7 billion and 30,000 QALYs annually. Those in produce, dairy products, seafood, breads, beverages, and complex foods – within FDA's jurisdiction – cost about $6 billion and 24,000 QALYs.

    Deli meats and eggs, which are jointly regulated, cost an additional $1.8 billion and 7,000 QALYs. Salmonella, which causes more disease than any other foodborne pathogen, is found in foods regulated both by the FDA and FSIS.

    The FSMA focuses on increasing the FDA's food safety tools but does not include a parallel effort for FSIS. Some advocates have begun to call for legislation focused on strengthening regulations on meat and poultry production. In the meantime, however, there are opportunities for the agencies to work together on the most important food-pathogen combinations: the EPI report's authors suggest that the recently-formed Interagency Food Safety Analytics Collaboration, which includes CDC, FDA, and FSIS, could be used to explore interagency initiatives.

  • Poultry is the single riskiest food, primarily due to contamination with Campylobacter or Salmonella. New FSIS regulations for these two pathogens are set to go into effect in July 2011.

    Department of Agriculture (USDA) data suggest that the public health impact of these rules will be quite small: a two percent reduction in incidence of salmonellosis and a less than one percent change in campylobacteriosis, according to experts. Nevertheless, these regulations are an important step forward: it has been more than 15 years since USDA tightened performance standards for Salmonella, and this is the first time USDA has acted to regulate Campylobacter. The agency's research suggests that a number of slaughter establishments will fail to meet the new standard.

  • Four of the top ten pathogen-food combinations carry special risks for pregnant women: both listeriosis and toxoplasmosis can cause miscarriage, stillbirth, and neonatal death. The EPI report does not break out illnesses associated with pregnancy; however, it does cite previous studies that suggest that public education could make a difference. Pregnant women are often educated about the link between toxoplasmosis and pet cats but are less likely to know about the risk of contracting the disease from undercooked meat. Fewer than one in five pregnant women knew about the pregnancy-specific risks of Listeria, and less than one-third of the women who were aware of the risk understood which foods to avoid.

It has long been clear that America's food is not safe enough. Taken together, the top ten food-pathogen combinations cost about $8 billion and 37,000 QALYs each year. The EPI report offers both policymakers and regulators a roadmap to the most important risks on Americans' plates.

Image in teaser by flickr user yum9me, used under a Creative Commons license.