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Food Safety News

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Surveillance Key To Tackling Outbreaks

Time was that when consumers and merchants bought food from farmers in the surrounding area, it was relatively easy to figure out where food that got people sick came from.

Clusters of ill people were generally neighbors and family members who could compare what they had eaten or drunk and come up with ideas about the likely source of the problem.

what did you eat today.jpgFrom there, they could tell the farmer or store owner about the problem, warn their friends and neighbors about it, and make sure they got rid of any of the contaminated food before anyone ate or drank any more of it.

Food safety officials refer to that coordinated effort to trace a foodborne illness outbreak back to its source as “surveillance.”

Fast-forward to modern times, and the way we get our food has changed dramatically. Not only does the food we eat often cross state lines and international boundaries before getting to us, in the case of some food products, the ingredients can come from several states and countries.

That was the case in the 2007 E. coli outbreak involving hamburger patties produced by food giant Cargill.  Consumers were surprised indeed to learn that the meat that went into the patties, which were labeled “American Chef’s Selection Angus Beef Patties,” came from slaughterhouses in Nebraska, Texas and Uruguay, as well as from a processing plant in South Dakota that processes fatty trimmings and treats them with ammonia to remove bacteria.

In the recent Italian-style salami and sausage Salmonella outbreak, the U.S. Food and Drug Administration is investigating the supply chain of black pepper believed to have been imported from Vietnam as a possible source of the contamination.

Sometimes the actual source and location of a foodborne illness outbreak is almost impossible to detect.

That was true in the 2008 Salmonella outbreak, which was first associated with tomatoes but which months later was linked to raw peppers from Mexico based on a sample of a Serrano pepper and a sample of irrigation water from a farm in Tamaulipas, Mexico, both of which were contaminated with the same strain of Salmonella that triggered the illnesses in the United States.

In that case, it was four months before the Centers of Disease Control and Prevention could confirm the food source and location of the contamination.

Because time is of the essence when it comes to locating the source of a problem, local, state, federal, and even international agencies need to be able to quickly form surveillance teams to get to the root of the problem so that as few people as possible become ill, or die.

Unfortunately, a lack of coordination among agencies can be a weak link in surveillance efforts. With that in mind, the Council to Improve Foodborne Outbreak Response spent 3 years crafting peer-reviewed guidelines that provide a model for the kind of collaboration across professional, agency, and geographic boundaries that are essential in tackling foodborne illnesses.

“By harmonizing data collection, improving data sharing, and fostering new levels and modes of collaboration, we have the opportunity not only to contain outbreaks more promptly but also to learn more robustly the lessons they can teach for future prevention,” say food safety experts Michael Osterholm and Michael R. Taylor in the report’s foreword.

Timely surveillance is often a problem because the nation’s food distribution has become so complex.

That complexity was evident in the 2008-09 peanut-related Salmonella outbreaks. Although the source of the multi-state outbreaks was eventually linked to the Peanut Corporation of America, a processor that handled less than two percent of the U.S. peanut supply, the processed peanut products were used as ingredients in more than 3,900 products, among them cereals, cakes, cookies, and ice cream.

According to a recently released USDA report about the peanut-related Salmonella outbreaks, local and state health departments typically investigate between 400 and 500 foodborne illness outbreaks each year. Yet many of these investigations fail to find the source because it’s so difficult to identify and group cases of an outbreak within a short time period.

In a press release last summer, Assistant Senate Majority Leader Richard Durbin, D-IL, said that recent string of outbreaks and recalls were “not isolated incidents, but the result of an outdated, under-funded and overwhelmed food safety system.”

Durbin’s bill, the FDA Food Safety Modernization Act, includes provisions to strengthen and expand surveillance systems by making improvements aimed at ensuring speedy and efficient responses to outbreaks.

A similar bill passed by the House last summer, the Food Safety Enhancement Act of 2009, also takes aim at improving surveillance.

Supporters of the two bills are expecting Congress to send a final food-safety reform bill to President Obama for his signature in the coming months.

Dr. Timothy Jones, M.D., state epidemiologist for the Tennessee Department of Health and co-chair of the Council to Improve Foodborne Outbreak Response, told Food Safety News that changes in the American diet, which include the likelihood that the dinner on your plate has food from several different countries, makes surveillance ever more challenging and therefore ever more important.

That’s why he’s pleased to see that the food safety reform bills recognize the importance of surveillance.

“Without good surveillance, you won’t be able to recognize some of the outbreaks and trace them back to their source,” he said. “Good public health surveillance is key to identifying the problems. It really allows regulatory agencies to move fast. It’s a very important part of the process.”

lab-biologist-featured.jpgWhen looking at some of the weak links in current surveillance strategies, Jones said that in many cases, there are just not enough good people to conduct food safety surveillance. In some states, for example, epidemiologists working on food safety issues are also working on health problems such as swine flu and West Nile virus.

Yet Jones said that revving up food safety surveillance doesn’t call for a huge investment–that $5 million could put additional epidemiologists in every state, plus a handful at CDC.

“We need dedicated people with a specialty in food safety,” he said. “The bang for the buck would be really high. One big outbreak has a huge trickle-down effect. An investment in surveillance would be a small fraction of the costs and losses involved in an outbreak.”

When asked about successful surveillance models, Jones said Minnesota and Oregon are two of the states in the forefront.

Dr. Kirk Smith, DVM, foodborne diseases specialist with the Minnesota Department of Health, attributed his state’s success to a centralized state system of surveillance, as opposed to strategies in many other states where initial surveillance is done at the county level.

“There’s a lag time there,” he said, referring to the time it can take before there’s a recognition that cases in other counties match up with one another.

“We know as soon as we have only one or two cases, and we get an idea of the questions we should ask,” he said. ” If we had to wait for clusters of people to be reported, it might be 4 to 6 weeks after the fact.”

Standard procedure in Minnesota is that when a person exhibit
ing foodborne illness sy
mptoms goes to the doctor, the doctor will order a stool sample. If the sample shows signs of foodborne pathogens such Salmonella or E. coli, a report is sent to the state Health Department. By law, the lab has to send the sample to the state for DNA fingerprinting.

The case is also reported to state epidemiologists, who then start interviewing the ill person, or persons, to find the source of the infection.

“We’re doing interviewing at the state level instead of spreading it out in different counties,” Smith said. “It’s a more efficient use of resource money.”

The initial interviews are detailed and generally take about 27 minutes to complete. If subsequent interviews reveal new information, health officials go back and re-interview people who have already supplied information.

Bottom-line, said Smith, Minnesota’s centralized surveillance system allows for speedy response time, while also providing the experience and resources needed to conduct effective surveillance.

Pointing out that success breeds success, Smith said the state’s surveillance program has proven its worth.

“We solve outbreaks all of the time,” he said.

He referred to the 2008-09 Salmonella peanut butter outbreak as an example of that good track record.

According to a USDA report about the outbreak, the Minnesota Department of Health identified the likely source of the multi-state Salmonella outbreaks as King Nut peanut butter.

The upshot was that the FDA identified two peanut-processing plants owned by the Peanut Corporation of America as the source of the contamination.

“How much longer would it have gone on and how many more people would have gotten sick if we hadn’t figured out the source as quickly as we did,” Smith said.

Funding is key to improving surveillance.  Dr. David Acheson, former associate commissioner of Foods at FDA, told Food Safety News that the food-safety reform bills in Congress call for a $3 billion system and provide $100 million in new money through fees.

Under President Obama’s recently released budget proposal, FDA’s food safety programs would receive a 30 percent increase in funding for 2011. According to the agency, the president’s spending plan calls for an investment of approximately $1.37 billion to strengthen food safety efforts, up $318.3 million from 2010. 

But about 75 percent of FDA’s hefty increase in resources for food regulation will depend on the passage of an FDA food safety reform bill, which includes food facility registration fees.

The agency does not currently have the authority to collect the fees needed to fund its proposed budget increase.

According to the USDA, the FDA regulates about 80 percent of the U.S. food supply, with approximately 2,700 food-inspection staff members throughout the United States who are responsible for the oversight of roughly 44,000 U.S. food manufacturers and 100,000 registered food facilities.

FDA does not regulate domestic and imported meats, poultry, and processed egg products that are otherwise inspected by USDA’s Food Safety and Inspection Service.

Photo courtesy CDC/ Hsi Liu, Ph.D., MBA, James Gathany

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