Food Safety and Foodborne Illness: There Will Always Be Surprises

By:           Diane Wright Hirsch, MPH

Senior Extension Educator/Food Safety

dole spinach
Photo: FDA

I took on food safety as a focus of my Extension programming in the early 1990’s: little did I know that for the next 20-plus years my food safety educator life would be full of surprises. Early on, the issues were what a consumer would expect them to be—salmonella and eggs, salmonella and chicken, seafood as a source of a variety of foodborne illnesses. After all, these are all animal based products, high in protein, low in acid, the perfect breeding ground for the bacteria that cause much foodborne illness.

But at the same time, Listeria monocytogenes was an emerging pathogen that would soon become ubiquitous in the food processing industry. We learned that E. coli COULD survive an acid environment such as apple cider. And then came an onslaught of outbreaks related to fresh produce, which heretofore was not considered what were called, potentially hazardous foods or PHF, in the FDA Model Food code.

Like all science, the science of food safety is ever evolving. And so too are the unfortunate targets of the microorganisms that cause foodborne illness.

Some of the surprises over the years have resulted in additional regulation. The Jack in the Box E. coli outbreak (as well as others), was one driver of the 1996 USDA “Mega-reg” that required all meat and poultry processing plants to develop food safety systems based on HACCP or Hazard Analysis Critical Control Point programs. These programs lay the onus on the industry to identify the food safety hazards that could potentially affect their products and/or processes and to adopt controls to prevent the hazards or at least to minimize the risk of a foodborne illness from these hazards once their product gets into commerce and ultimately the consumer.

Similarly, it was a series of outbreaks affecting apple cider, apple juice (Odwalla, 1994) and other fresh juices that resulted in the FDA Fresh Juice HACCP regulation in 2001.

The FDA Food Code has also adapted over time as new foods or food processes have added risk to foods that weren’t identified as hazards in previous editions. Currently, seed sprouts, sliced melons, sliced tomatoes, and cut lettuces are all considered time-temperature for control foods (formerly PHF). Each of these were added following outbreaks that affected them. All are low acid foods that support the growth of microorganisms.

So, yes, outbreaks can surprise us. Consider some of the food products that have shown up in the news recently.

  • Deer antler tea and botulism—affected two in California. (Maybe the biggest surprise here is that someone actually drinks deer antler tea?)
  • coli in flour, including a rare form, O121 in a Canadian flour source
  • Botulism in carrot juice (was mishandled by consumers)
  • A variety of outbreaks tied to pet food
  • Frozen vegetables: this Listeria outbreak and subsequent recalls affected as many as 350 consumer products sold under 42 brand names.
  • Chicken pot pies (a result of unclear labeling, consumer handling)
  • Not an outbreak, but still a hazard—golf balls in hash browns?
  • Pepper and other spices in ready to eat products (coatings on cheese or salami), in spice mixes and simply on their own in a bottle.

Sometimes, it is not the outbreak that surprises us, but the extent of the consequences. Raw milk is an example of this. Outbreaks tied to raw milk are not unusual, but a soon to be released report from the Centers for Disease Control indicates that unpasteurized milk and cheese products caused 96% of illnesses attributed to dairy products. This is an important statistic.

In several recent outbreaks, including the Peanut Corporation of America and the Jensen Brothers Farm Listeria outbreak in cantaloupe, the owners and some employees of the companies were arrested and given hefty fines, probation, and in some cases, prison sentences.

Lessons learned, changes made

There will always be surprises. In my food safety courses for industry personnel, I use some of these examples as lessons for those who insist that an outbreak or recall will never happen to them. The Food Safety Modernization Act (FSMA) was itself the end result of many surprises. The foods regulated by the FDA are not under as much scrutiny as those regulated by the USDA. Inspections are less frequent. Businesses really do need to take responsibility for the safety of their food as the government agency that oversees them simply does not have the resources to do so. So after a series of outbreaks tied to FDA regulated foods (peanut butter, cheese, spinach, melon, sprouts, pet foods and others) that were not previously required to have a food safety program in place, FSMA was adopted. Included in the regulation were rules addressing fresh produce, processed foods (except those currently under HACCP regulations such as juice and seafood), pet foods and imports. A thriving third party audit industry has also developed as customers of food processors seek greater assurances that the products they are buying are produced under a food safety program.

What is a consumer to do?

Consumers should simply remain vigilant. Keep up on recalls or outbreaks that affect the foods you eat. If you like to get emails, you can sign up for notifications of recalls on both the FDA site ( and the USDA Food Safety Inspection Service site ( Consider using shopper loyalty cards when your supermarket makes them available. They are often used to contact consumers who may have purchased a product associated with an outbreak or recall.

A more reasonable approach may simply to be to learn about how you get sick from food. Learn about the importance of temperature controls, including cooking times and temperatures, keeping cold foods cold, and cooling foods properly. Learn about cross contamination of ready to eat foods with contaminated foods (raw meat), dirty hands or dirty countertops. Don’t eat raw foods that should be cooked for safety (raw, undercooked meat or eggs or doughs for example) and handle ready to eat foods like lettuce and cantaloupe carefully. Follow cooking instructions on the processed foods you buy—especially if you are using a microwave oven. You can learn about how to handle food safely at the UConn Food Safety website ( or by visiting .

In other words, take responsibility for the foods that you handle. While that may not ensure that you will be forever free from foodborne illness, at least you will be less likely to be the cause of that illness.

Listeria and Fresh Produce

What is Listeria and why is it showing up in fresh produce?

By Diane Wright Hirsch, MPH, RD

UConn Extension Educator – Food Safety


dole spinach
Photo: FDA

Yet another outbreak of Listeria monocytogenes has been attributed to fresh produce: bagged lettuce in this case. You may recall the 2011 outbreak associated with cantaloupe that turned out to be the deadliest Listeria outbreak ever in the US. And, Listeria was also the cause of an outbreak tied to apples (and caramel apples) in 2015.

It’s not only produce that has been associated with Listeria contamination. In 2015 alone, there were over 45 recalls of various FDA regulated food products, including pet foods (raw/frozen for the most part), deli salads, cheeses, sprouts, processed salmon products, and ice cream (Blue Bell, Jeni’s). Recalls also were carried out for apples and apple slices, spinach, and frozen vegetables.

So what is Listeria monocytogenes (LM) and where is it coming from?

LM is a bacterial species that was first described in 1926 after an outbreak in guinea pigs and rabbits. For many years, it was known as a disease of animals, including small ruminants, often called “circling” disease. One source of the disease is spoiled silage, causing illness during the winter and spring months after long-term storage of silage. When I first started working in food safety education, it was known as an “emerging pathogen” as it was just starting to become a big problem in the human food system.

The first documentation of a major human outbreak was in 1981. This Canadian outbreak was attributed to coleslaw made from cabbage likely contaminated by sheep manure. The outbreak resulted in 41 cases of illness, 34 of which were pregnant women. There were 18 deaths.

Since then, Listeria has been the cause of outbreaks in dairy products, including a variety of cheeses, processed meats such as hot dogs and cold cuts, sprouts, and, most recently fresh produce. Increased testing over time by government agencies including the United States Department of Agriculture Food Safety Inspection Service (USDA/FSIS) and the US Food and Drug Administration (FDA), has also resulted in many recalls that may have helped to reduce outbreaks from products that are removed from the marketplace.

So why is this now a problem for fresh produce?

Listeria has become pretty much ubiquitous in the food-processing environment. While it’s certainly present in the soil, water, and animal feces, the big problems often arise from food that is processed and/or held in a processing or storage facility that is wet and cold. This is where the bug can grow and multiply if not dealt with by employing scrupulous sanitation programs.

Some of the characteristics of Listeria that make it a particular problem are:

  • While most consumers are likely to think that it is what they ate in the last 48 hours that made them sick, Listeria has a long incubation period—as much as 3 weeks. This means that when you eat a food contaminated with Listeria, you may not feel ill or experience some of the worst complications, such as miscarriage until weeks later. Foodborne illness experts often start an investigation with a food recall. Do you remember what you ate for lunch on a Tuesday two or three weeks ago?
  • Foods that may be more likely to be contaminated with Listeria are ready to eat foods such as cold cuts, other deli foods, cheese or some fresh fruits and vegetables. Therefore, we do not cook it away.
  • While most people are at least somewhat aware of the risk of Listeria from hot dogs, cold cuts or unpasteurized cheeses, they are less likely to connect it to bagged lettuce or cantaloupe. In the 1990s there was a string of outbreaks related to hot dogs and cold cuts. In 2003, FSIS passed a Listeria Rule that addressed many of the problems in that industry.
  • Listeria likes cold temperatures-found in refrigerators, coolers and cool processing rooms. Wet AND cold processing environments are Listeria’s
  • Inadequate or ineffective sanitation practices can miss the Listeria that might be hiding in floor drains or biofilms, which are a substance not unlike plaque on your teeth that forms when bacteria adhere to a surface, then create a matrix that can build up over time and protect the bacteria from routine cleaning practices. Periodically, these biofilms can break open, releasing the bacteria to contaminate a seemingly clean surface.

Several Listeria outbreaks have been traced to packing facilities (such as the recent apple and cantaloupe outbreaks) where cold, wet environments that are not cleaned adequately can be the problem. Floor drains, conveyor rollers, dunk tanks can all be sources of this bug. Perhaps a contributing condition might be the presence of animal manure on the farm.

Yet another issue is that consumers are demanding that their fresh produce is provided in ever more convenient forms—cleaned, chopped lettuce in bags, sliced apples, cut celery, coleslaw mix, to name just a few. The more handling, the more opportunity for contamination.

So what is a consumer to do?

First, know your risk. Listeria is a bit of a chameleon. We are all routinely exposed to LM, due to its ubiquitous nature. Yet we do not all get sick from it. A young adult with a healthy immune system may make it through a bout of Listeriosis with barely a symptom. According to the Centers for Disease Control, “at least 90% of people who get Listeria infections are in a higher risk group. Healthy children and adults occasionally get infected with Listeria, but they rarely become seriously ill.”

So, if you are 65 or older, have a compromised immune system due to illness or medical interventions, and if you are pregnant, avoid foods that are more likely to be contaminated with LM. Do not eat foods from the deli case, cold cuts or hot dogs unless you heat them to 165 degrees F. Do not drink raw milk or eat cheeses made from raw milk. Fresh produce is trickier. You certainly can cook most fruits and vegetables, but you may not want to cook everything—though you could add spinach and other greens to a hot soup. So the next best thing is to handle fresh fruits and vegetables safely.

  • Rinse raw fruits and vegetables, thoroughly under cool running tap water before eating, cutting, or cooking. Even if the produce will be peeled, wash it first. There is no need for special veggie washes. Studies have shown that cold water alone (along with brushing when appropriate) can remove 85-98% of bacteria.
  • Scrub firm produce, such as melons and cucumbers, with a clean produce brush (wash the brush in a dishwasher after using).
  • Dry the produce with a paper towel.
  • Store fresh fruits and vegetables in a clean, DRY, location. Always refrigerate once cut. Store away from raw meats, poultry, fish or eggs.

And, keep your refrigerator clean.

Remember that Listeria monocytogenes likes cold, wet environments—even your home fridge. Using an appliance thermometer, make sure that your refrigerator is at 40°F or lower and the freezer 0°F or lower.

Be sure to clean up all spills in your refrigerator right away–especially juices from hot dog and lunch meat packages, raw meat and poultry, and, of course, those rotting fruits and veggies that lie forgotten at the bottom of the drawer. Regularly clean the inside walls and shelves of your refrigerator with hot water and liquid soap, then rinse and pat dry.

And finally, be sure to monitor your fruit and veggie storage drawer. Throw out anything that is beginning to spoil, is moldy or has other signs of decay.

For more information on safe handling of produce and preventing foodborne illness, go to or contact the Home and Garden Education Center at or 1-877-486-6271.

Safe Food Handling from Farm to Table

Written by Patsy Evans for Naturally@UConn and originally posted on October 14, 2014

Screen Shot 2014-10-20 at 3.38.24 PMHearing the word ‘outbreak’ makes many people anxious. E. coliO157:H7, spinach, 2006. Salmonella, peanut butter, 2009. Listeria, cantaloupe, 2011. Diane Hirsch, UConn Extension educator for food safety, easily lists previous food-borne pathogen outbreaks. But, fear does not paralyze her.

Instead, she works in classrooms and on farms to make sure that locally produced food, which ends up on tables in New England, is as safe as possible. Her mission: “safe food handling from farm to table.” Her audience includes growers who put produce in boxes on their farms, commercial artisanal cheese makers and home cooks who preserve food in their kitchens.

With the help of over $82,000 in USDA grants, Hirsch trains farmers to follow Good Agricultural Practices (GAP) and processors to develop food safety plans. She labors to see farm products that are, according to USDA, “produced, packed, handled, and stored in the safest manner possible to minimize risks of microbial food safety hazards.”

Because of past outbreaks, grocery store chains that buy food from farmers are putting more pressure on them to follow food safety guidelines and submit to voluntary audits. Hirsch estimates that 12 to 14 Connecticut farmers are currently GAP audited. She wants her training programs and farm visits to increase that number by “helping people do what they need to do” in reducing the possibility of contamination and preparing for audits.

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