Food Protection Connection: FAQs: Salmonella & Produce

(reprinted from Dietary Manager, September 2008)

The Summer ’08 outbreak of Salmonella illness has left many questions in the minds of dietary managers. At the time of this writing, more than 1,200 people in 43 states have developed foodborne illness since April 2008, all with a particular strain of Salmonella Saintpaul bacteria. The outbreak also affected Canada. Officials are calling this one of the largest foodborne illness outbreaks yet. The illness causes fever, diarrhea (which may be bloody), nausea, vomiting, and abdominal pain. Less commonly, the bacteria can cause endocarditis and arthritis, according to the CDC. Here are some questions and answers about this outbreak.

Q: Do we know the source of the illness?

A: Not definitively. As of press time, the FDA confirmed that Salmonella Saintpaul had been found in jalapeno peppers in a produce distribution center in Texas. We can consider this a very important clue, but not yet a complete answer. Explains the FDA, “The jalapenos were grown in Mexico; however, that does not mean that they were contaminated in Mexico. Fresh produce often changes hands many times in the supply chain from farm to table, and the contamination might have occurred at any point in the chain.” (FDA Salmonellosis Outbreak, July 21, 2008). The FDA states that this finding does not explain all cases of illness to date. The next step is to follow the trail through the supply chain to look for common links.

Q: How can Salmonella bacteria get into peppers, tomatoes, or other fresh produce?

A: Salmonella bacteria and E. coli, both potential agents for foodborne illness, are associated with animal and human feces. One concern is that these bacteria can contaminate water and soil in areas where crops are grown. This is called “environmental contamination.” Produce can become contaminated in the field, or through irrigation or crop sprays that rely on unsafe water supplies. Harvest and postharvest processing are concerns, too. Consider the potential for unsanitary human hands (poor hygiene); unsanitary tools, storage bins, or facilities; or unclean water used for washing produce and making ice for storage and transport. Any of these steps in the flow of food can transfer pathogens to produce. Officials point out that the land use environment, and even the presence of farm animals or manure, can impact food safety.

Q: Was environmental contamination responsible for the outbreak involving E. coli bacteria and spinach?

A: Yes. In October 2006, investigators found E. coli in environmental samples collected at a spinach-growing ranch in California. The strain matched that of the bacteria causing the outbreak. The same strain also showed up in water taken from a stream, cattle feces taken from pasture areas, and wild pig feces collected on the ranch. All of this underscores the idea that a pathogen can contaminate the growing environment, making produce potentially unsafe.

Q: Has there been a recall in this year’s Salmonella outbreak?

A: Yes. On July 21, 2008, the FDA announced a recall of certain jalapeno peppers that had been distributed to Texas and Georgia.

Q: Why did this investigation span such a long time?

A: The outbreak was complex and occurred on a large scale. Investigative procedure is to identify common foods in the diet histories of those who are ill, then trace back these foods through the supply chain to search for sources. Investigators then test food samples to look for bacteria with a matching genetic fingerprint. Unfortunately, it was difficult to trace these illnesses to a specific food. The FDA states, “Among the complications that arise for tomatoes in this process is that lot numbers and other information identifying the tomatoes’ growers might not be included on the receipts and shipping records. In some cases, investigators have to rely on reviewing records and interviewing the personnel who handle such matters, which increases the time and resources needed to trace implicated tomatoes back to their sources. Another complication that delays the investigation is that often there is no package, no product code, no sell-by date, and no marking on the tomato at the retail level.”

Q: As of press time, what is the FDA recommending to foodservice operators?

A: As of July 18, 2008, the FDA advises that foodservice operations should not serve or handle raw jalapeno peppers. The FDA adds, “Attempts to wash Salmonella contamination that may be present on these peppers is not likely to eliminate the organism, because of Salmonella’s physical properties, and is likely to result in cross contamination. Attempts to peel the peppers are not recommended, as this is likely to introduce any contamination on the exterior of the product into the interior, making elimination of the organism even more unlikely. Attempts to kill Salmonella by cooking may result in cross contamination and likewise are not recommended.” Regarding tomatoes, FDA advice (as of press time) is as follows: “Foodservice providers… may resume offering customers any type of tomato, including raw red plum tomatoes, raw red Roma tomatoes, and raw round tomatoes, from any region.”

Q: What can a dietary manager do to help keep produce safe in a foodservice operation?

A: It is important to consider fresh produce as potentially hazardous food and implement produce safety guidelines in your standard operating procedures. The FDA advises:

• When fresh produce is received, follow storage directions regarding temperature, “use by” dates, etc. Avoid using damaged and partially decayed produce.
• Store raw produce such that it does not contaminate other foods with soil, etc. Store any fresh produce, whole or cut, where other products—especially raw meat and poultry—cannot cross contaminate it.
• Segregate fresh produce from other refrigerated foods in refrigeration units by using a separate set of storage racks or separate cooler, if possible. Cover and store washed cut produce above unwashed, uncut fresh produce. Store all produce off the floor.
• Wash hands thoroughly with soap and warm running water before and after handling fresh produce.
• All sinks, utensils, cutting boards, slicers, etc., should be washed, rinsed, and sanitized before use with fresh produce.
• Always wash fresh produce under running, potable water before use. Soaking produce or storing it in standing water is not recommended for most types of fresh produce.
• Refrigerate food prepared with raw fresh-produce ingredients.
• Minimize re-use of freshly prepared dishes containing raw produce. Examples include dishes made with raw tomatoes, cilantro, and hot peppers, such as salsa and guacamole.

Sue Grossbauer, RD, author of several books, and a regular contributor to DIETARY MANAGER magazine.