Protecting Against Foodborne Threats to Health:  The Practice and Policies of Surveillance, Proactive Prevention; Outbreak Investigations;
and International Coordination

The Summary Report of this Workshop was released in September 2006.

Workshop Objectives

Context

On December 2, 2004, then Secretary of Health and Human Services Tommy Thompson warned of the possibility of agricultural terrorism and pandemic flu as he joined the queue of cabinet officers heading for the doors. At a press conference called to announce his departure, Thompson said he was surprised that terrorists hadn't tried to poison the food supply yet, given how easy it would be to do and the fact that the United States imports a lot of food products from the Middle East. Despite dramatic increases in inspections of food imports, only "a very minute amount" of food is tested at ports and airports, Thompson said."  The following day, President Bush downplayed this stark warning from his resigning health chief that the nation's food supply is largely unprotected from terror attack. Bush said that the government is doing what it can to safeguard the public from threats, but much work remains. "We're a large country, with all kinds of avenues where somebody could inflict harm."

The Food and Drug Administration on Monday, December 6, 2004, announced the final portion of its post-9/11 rules to protect the USA's food supply. The action comes just four days after outgoing Health and Human Services Secretary Tommy Thompson said he couldn't understand why terrorists haven't attacked the U.S. food supply, because "it's so easy to do." The rules are the final piece of new authorities given to the FDA by Congress in the wake of the anthrax contamination that followed the attacks of Sept. 11, 2001. That contamination further highlighted the nation's vulnerability to less well-known forms of terrorism and harassment.

The malicious contamination of food for terrorist purposes is a real and current threat, and deliberate contamination of food at one location could have global public health implications. Outbreaks of both unintentional and deliberate foodborne diseases can be managed by the same mechanisms. Sensible precautions, coupled with strong surveillance and response capacity, constitute the most efficient and effective way of countering all such emergencies, including food terrorism. At a minimum, strengthening existing communicable disease control systems to ensure that surveillance, preparedness and response systems are sufficiently sensitive to meet the threat of any food safety emergency is an essential component of a food safety system. Establishment and strengthening of such systems and programs will both increase the capacity to reduce the increasing burden of foodborne illness and help address the threat of food terrorism.

Background

According to the CDC (2003) more than 250 foodborne diseases have been described. Symptoms vary widely depending on etiologic agent. Diarrhea and vomiting are the most common symptoms of food-borne illness. Many different bacteria (e.g., Campylobacter, Salmonella, E. coli O157:H7), viruses (e.g., caliciviruses), and parasites (e.g., Giardia, Cyclospora), and natural and manmade chemicals (e.g., mushroom toxins and heavy metals) have been associated with foodborne illness in the United States and elsewhere. Foodborne contaminants are estimated by the Centers for Disease Control and Prevention to cause 76 million illnesses, 325,000 hospitalizations, and 5,200 deaths in the United States each year. Known pathogens account for an estimated 14 million illnesses, 60,000 hospitalizations, and 1,800 deaths annually. Sequelae associated with foodborne pathogens include:  septicemia, abortion, localized infections, arthritis, hemolytic uremic syndrome, Guillain-Barre syndrome, and death. The true incidence of food contamination is unknown, although the proportion of outbreaks caused by fruits and vegetables consumed without cooking has increased over recent decades.

Medical costs and lost wages due to foodborne salmonellosis, only 1 of many foodborne infections, have been estimated to be more than $1 billion/year.  All persons, including infants, the elderly, and the immunocompromised are at increased risk of serious illness and death associated with foodborne pathogens. Preventing foodborne illness and death remains a major public health challenge. 

New Challenges: Food as a vehicle for terrorist acts

Deliberate contamination of food by chemical or biological agents can occur at any vulnerable point along the food chain - from farm to table - depending upon both the food and the agent.  For example, members of a religious cult in The Dalles, Oregon, contaminated salad bars in 1984 with Salmonella typhimurium, causing 751 cases of salmonellosis.  The attack appeared to be a "trial run" for a more extensive attack intended to disrupt local elections.  The cult was also in possession of strains of the causative organism of typhoid fever, a severe invasive illness.  In 1996, a disgruntled laboratory worker deliberately infected food to be consumed by colleagues with Shigella dysenteria Type 2, causing illness in 12 people.  Although few incidents or threats of deliberate contamination of food with chemical or biological agents on a massive scale have been documented, it is prudent to consider basic countermeasures.

The potential impact on human health of deliberate adulteration of food can be estimated by extrapolation from the many documented examples of unintentional outbreaks of foodborne disease.  The largest, best documented, incidents include an outbreak of S. typhimurium infection in 1985, affecting 170,000 people that was caused by contamination of pasteurized milk from a dairy plant in the US.  An outbreak of hepatitis A associated with consumption of clams in Shanghai, China, in 1991, affected nearly 300,000 people and may be the largest foodborne disease incident in history.  In 1994, an outbreak of S. enteriditis infection from contaminated pasteurized liquid ice cream that was transported as a pre-mix in tanker trucks caused illness in 224,000 people in 41 states.  In 1996, about 8,000 children in Japan became ill, including some deaths, from consumption of raw radish sprouts contaminated with E. coli O157:H7, in their school lunches.

Episodes of foodborne illness caused by chemicals have also been reported in the published literature.  The chemicals that can contaminate food include pesticides, mycotoxins, heavy metals and other acutely toxic chemicals such as cyanide and dioxin.  In perhaps one of the most deadly incidents, over 800 people dies and about 20,000 were injured, many permanently by a chemical agent - most likely dioxin - in contaminated cooking oil sold in Spain in 1981. In 1985, 1,373 people in the Midwest reported becoming ill after eating watermelon grown in soil treated with aldicarb.  More recently, reports that Ukraine's opposition leader and presidential candidate, Viktor Yuschenko, had been poisoned by dioxin has led to accusations that Kiev authorities were behind the poisoning.

Contamination of food in one country can also have a significant effect on health in other parts of the world.  In 1989, staphylococcal food poisoning the the US was associated with consumption of mushrooms that had been canned in China.  Outbreaks of cyclosporaisis in the US in 1996 and again in 1997 were linked to consumption of raspberries imported from Guatemala.  Many similar outbreaks have been reported in the literature.

Workshop Objectives

As transborder mobility of humans, animals, food, and feed products increases, so does the threat of the spread of dangerous pathogens, contaminants and infectious disease through raw and finished food stuffs. While new global markets have created unprecedented economic opportunities and growth, the benefits have not been equally distributed, and the risks - especially the health risks - of our increasingly interconnected and fast-paced world continue to grow. Although the burden is greatest for the developing world, infectious diseases are a growing threat to all nations. However, the same globalizing forces that create such rampant opportunity for pathogens also can provide mechanisms for innovative, global efforts to control infectious diseases.

In an attempt for the forum to understand the nature and extent of foodborne threats to health and what policies and practices are in place to identify and mitigate these risks, the presentations and discussions of the workshop will be structured to explore the existing knowledge and unanswered questions indicated by (but not limited to) the following topics:

• Globalization of the food supply
• The Burden of Illness associated with foodborne threats to health
• The Food Supply "Threat" Spectrum - Case Studies
• Regulatory Responsibility - Domestic and International
• Threat Reduction Research and Policy Opportunities