The Centers for Disease Control and Prevention is an arm of the Department of Health and Human Services. The CDC is one of the foremost investigative bodies in the world when it comes to tracking foodborne illness and foodpoisoning. The agency’s role in the investigation of foodborne illness outbreaks–e.g. the Salmonella outbreak linked to pepper covered salami products manufactured by Daniele, Inc.–is critical to the safety of our food supply and the lives of every person in the country.
The CDC’s role in national foodborne illness outbreaks:
Interestingly, though, the CDC is often not the agency that "discovers" otubreaks of foodborne disease like the salami Salmonella outbreak. On its website, the CDC details its typical role in the investigation of many foodborne illness outbreaks:
Most foodborne outbreaks are identified and investigated by local and state health departments. CDC provides consultation on some of those, as well as assistance on request for outbreaks that are particularly large, unusual, or severe.
In recent years, large multi-state foodborne outbreaks have become more common, because better surveillance identifies outbreaks that would previously have been missed and because an increasingly centralized food supply means that a food contaminated in production can be rapidly shipped to many states causing a widespread outbreak.
The Department of Health and Human Services’ Centers for Disease Control and Prevention (CDC) works with a number of public health partners, including state, county, and city health departments, and the federal regulatory agencies, such as the United States Food and Drug Administration (FDA), the United States Department of Agriculture – Food Safety and Inspection Service (USDA/FSIS) , and the Environmental Protection Agency. During a multi-state foodborne disease outbreak, CDC serves as lead coordinator between public health partners to detect the outbreak, define its size and extent, and to identify the source.
CDC maintains and monitors several disease surveillance and outbreak detection systems in collaboration with public health partners. PulseNet, a sophisticated outbreak detection system, is a national surveillance network of CDC, state, and local public health laboratories and federal food regulatory agency laboratories. PulseNet performs pulsed-field gel electrophoresis (“DNA fingerprinting”) on disease-causing bacteria that may be foodborne to find clusters of cases that might be related.
Once a potential multi-state outbreak has been detected, CDC’s OutbreakNet Team engages to investigate it. By collaborating with public health partners, OutbreakNet leads the epidemiologic investigation of multistate outbreaks. OutbreakNet coordinates communications among states and may lead epidemiologic studies. These are studies to develop a short list of suspect foods or other exposures (“hypothesis generation”), to identify food exposure associated with illness (“case control studies”), and to determine how the food became contaminated. CDC also provides assistance in the field to any state requesting it. CDC’s laboratories maintain PulseNet surveillance to identify new cases, conduct advanced laboratory tests of disease-causing microbes, test suspect foods, and provide technical support to OutbreakNet and public health partners as part of the investigation.
The Salmonella outbreak linked to salami
The salmonella outbreak and recall linked to Daniele, Inc’s salami product is a perfect example of how the CDC works with states around the country in the investigation of these outbreaks. This outbreak involved some admittedly tough circumstances, including a product with a long shelf life, national distribution, and the fact that many people eat salami fairly casually and without specific recall. These are all circumstances that can frustrate the efforts of public health officials trying to investigate a known cluster of salmonella illnesses.
Despite the fact that people were falling ill as early as July 2009, it was not until this month (january 2010) that the puzzle pieces finally fell into place. Bill Keene, PhD, the senior epidemiologist with the State of Oregon, first called the link between Daniele, Inc’s salami product and the Salmonella montevideo illnesses nationally. The following excerpts from a discussion with Dr. Keene appeared in articles in both the Oregonian and the Washington Post via the AP on January 23:
“This is a weird outbreak in a lot of ways because it’s been such a long investigation,” Keene said. "We’ve gone down a lot of dead ends until the puzzle pieces started to fit together."
Many of those questioned did not point to salami, Keene said. “They were questioned left and right and they were asked about salami and very few of them said yes,” he said.
Keene said, investigators re-interviewed people who were thought to be part of the outbreak, such as members of a hunting party from the South who had been to the Great Plains and responded to new questions with answers such as, "Now that you mention it, we did stop at a Wal-Mart in South Dakota and buy some salami."
Keene said Saturday that the cause of the sickness was difficult to track and some questions remain, such as whether it was the meat or the pepper that was contaminated. Some scientists suspect that the pepper on the salami, which is known to pose a risk for salmonella, is at the heart of the outbreak.
“The company doesn’t test or process the pepper that they buy,” Keene said. “That doesn’t mean that they’re bad people, but it may have slipped through their quality assurance program.”