Eggs. Melon. Sprouts. Honey Smacks cereal. Is nothing safe from salmonella this year? Salmonella, which is a foodborne bacteria that typically causes diarrhea and vomiting, keeps making headlines due to several recent outbreaks in quite the variety of foods over the past several months.
An outbreak of salmonella is defined by the Centers for Disease Control and Prevention (CDC) as “two or more people [who] get the same illness from the same contaminated food or drink.” So by this definition, there have been eight outbreaks (a total of 703 reported infections) of foodborne salmonella, in addition to two outbreaks linked to live animals, in the U.S. this year—and it’s only June.
Looking back at outbreaks year-over-year, the worst year of the last 12 listed by the CDC (so from 2006 to 2018) was 2011, which also saw eight different foodborne salmonella outbreaks over the course of the entire year.
While it’s true that we’re currently pacing at a faster number of salmonella outbreaks compared to years past, it’s pretty difficult to pinpoint a specific reason for why that might be the case.
“There have been more multi-state foodborne outbreaks announced than we typically see by this time of year,” Laura Gieraltowski, foodborne outbreak team lead with the CDC’s Division of Foodborne, Waterborne, and Environmental Diseases, told SELF via email. “However, it’s too soon to tell at this point whether this represents a new trend.”
So how do these bacteria contaminate foods as seemingly unrelated as eggs and cereal? Types of salmonella bacteria are very diverse and can live in an enormous variety of animal species, which can then spread the bacteria in all sorts of ways.
In fact, there are about 2,500 different salmonella serotypes (which means that the bacteria are very similar to each other but vary slightly in their genetics). Only about 100 of the types typically cause human disease.
Though foodborne outbreaks are most commonly due to livestock and poultry products (like eggs), salmonella contamination can come from just about anywhere. Wild animals, including birds and rats, can carry salmonella into food processing facilities. Dog and cat food can introduce salmonella into a household, where children can then contract it from these family pets. Other pets, such as guinea pigs, baby chicks, and various lizard species, can bring salmonella into the house as well. (Outbreaks traced to guinea pigs and backyard chickens have sickened 133 people so far in 2018.)
Each outbreak eventually ends, but sometimes it does so without health officials being able to positively identify the origin of contamination.
The millions of contaminated eggs that made headlines in April were traced to a single vendor and likely came from the laying hens. Similarly, an outbreak linked to chicken salad in February was distributed by one company and probably came from contaminated chicken meat. But while the dried coconut outbreak that occurred at the beginning of the year and reached nine states was eventually traced back to a product sold by one company, it’s unclear where the bacterial contamination came from.
But let’s look at the outbreak of salmonella in kratom (a plant that can have both stimulant and sedative effects and can be consumed as pills, powder, or tea) this past February: This outbreak is now considered over after several contaminated products were recalled, but it’s unclear how the plant was contaminated by salmonella in the first place. To further complicate the issue, there may not have been a single source of contamination, given that multiple types of salmonella were found in samples from several different vendors.
Meanwhile, we’re only beginning the investigation into Honey Smacks, which seem to be an odd vehicle for a salmonella infection. For one thing, they’re cooked (which would kill bacteria that came into contact with the cereal before the heat stage), and they’re not a meat or poultry product, the main sources of salmonella-related illnesses in humans.
But this isn’t the first salmonella outbreak to be somewhat mysterious in the early stages: In 2009, a large outbreak of salmonella was traced to peanut butter that eventually sickened more than 700 individuals in 46 states. After tracing contamination back to a processing facility, inspections revealed “roaches, rats, mold, dirt, accumulated grease and bird droppings during their raid,” according to CNN, as well as a leaky roof that could have allowed salmonella to grow in the otherwise dry building. In a landmark case, the plant’s CEO, food broker, and safety manager were given jail sentences for their role in facilitating the outbreak.
As you can see, even though it might seem absurd for the bacteria to sneak its way into, say, a random cereal brand, it’s not actually that surprising or unfathomable given that salmonella can spread in so many possible ways.
Even if we had immaculate food safety policies in place, it still wouldn’t guarantee the end of these types of foodborne outbreaks.
Despite these recent outbreaks, Gieraltowski emphasized that the U.S. food supply is “one of the safest in the world.”
Partly in response to the peanut butter outbreak, President Obama signed into law the Food Safety Modernization Act (FSMA) in 2011, which aimed to better prevent these types of foodborne outbreaks rather than merely control them after they begin. But though funding for FMSA increased annually under the Obama administration, it has never been fully funded. Under the Trump administration, funding is even more precarious. An early budget proposal sought to cut funding for this program, but ultimately it still saw a small increase for 2018.
Still, it’s always a good idea to practice food safety habits, like properly cooking and storing food as recommended, which can help reduce the risk of consuming contaminated food items.
Gieraltowski also suggested following the CDC on social media (including Facebook and Twitter) in order to be alerted about outbreaks and recalls as early as possible. Then, if you have any of the recalled food on hand, throw it away. “Even if some of the food was eaten and no one became sick, throw it away to be safe,” she cautioned.
If you do become ill, the illness typically resolves on its own without any need for medical treatment if you are a healthy adult. But you still play a key role in solving foodborne outbreaks: See your doctor and report your illness to the health department. And don’t ignore the call when the health department reaches out to ask about your illness, Gieraltowski advised. “They’ll ask you questions about what you ate and things you did in the week before you got sick. This information helps us find the source—a clue from one sick person can sometimes solve an outbreak.” Even if we aren’t sure yet whether this will be a record-setting year for salmonella, following these procedures can reduce your own chances of becoming part of a statistic.
Tara Smith, Ph.D., is an infectious disease epidemiologist and professor at the Kent State University College of Public Health.