Vulto Creamery of Walton, New York, has recalled several of its soft raw-milk cheeses due to possible contamination with listeria monocytogenes, a potentially dangerous bacteria that can cause food poisoning. There have reportedly been two deaths and six people hospitalized, all of whom were sick with similar strains of the bacteria linked to the outbreak.

The company has recalled all lots of its Andes, Blue Blais, Hamden, Heinennelli, Miranda, Ouleout, Walton Umber, and Willowemoc raw-milk cheeses, which have been distributed nationwide, but were mostly sold at restaurants, grocery stores, and other retailers in the northeast and mid-Atlantic states, as well as in California, Chicago, Oregon, Portland, and Washington, D.C.

Jan. 4, 2018 update: Read “
Avoid Romaine Lettuce for Now, Consumer Reports Says” for details on how this salad green is likely the cause of recent cases of E. coli food poisoning.

These cheeses are only the latest in a flurry of recalls in the past year due to possible listeria contamination. Outbreaks of listeriosis (the infection caused by listeria bacteria) have also been connected to contaminated cookie dough, frozen vegetables, and waffles.

Not everyone exposed to listeria bacteria gets sick from it, but when they do, it can cause serious illness. About 94 percent of people who get listeriosis must be hospitalized—and about 16 percent of people die from it. Symptoms can include a fever along with diarrhea, muscle aches, or other gastrointestinal symptoms, and headache. If the infection spreads to the nervous system, they may also experience a stiff neck, confusion, loss of balance, and convulsions. Listeria poses a special risk to pregnant women, who are at an increased risk of a miscarriage or stillbirth if they are infected. It's also more dangerous for the very old, young children and newborns, and people with immune-suppressing conditions.

Here, what everyone should know about this latest listeria outbreak, and what you can do to protect yourself.  

Why Have These Raw-Milk Soft Cheeses Been Recalled?

Vulto Creamery’s initial recall came after public health authorities linked the outbreak to a contaminated sample of Ouleout cheese found in the home of one of the deceased in Connecticut. That particular strain was then linked to the strains that caused six illnesses and one other death in four states.

Soft cheeses made with raw (unpasteurized milk) are normally safe to eat, but have long been known to be a higher risk food for listeria contamination than pasteurized and hard cheeses. Soft cheeses include feta, brie and Camembert, queso fresco, queso blanco, and Panela. The risk is greatest if these cheeses are made with unpasteurized milk, but according to the CDC, some soft cheeses made from pasteurized milk also have caused listeria infections, most likely due to contamination during the cheese-making process.

What Should I Do If I Bought or Ate the Recalled Cheese?

If you’ve purchased any of these cheeses, bring them back to the store for a refund. If you choose to throw them away instead, the CDC says to seal the cheese in a plastic bag and place it into a sealed trash can to prevent other people or animals from eating it. Wash the refrigerator drawer and any other container you stored the cheese in with soap and hot water; and wash any other cutting boards, plates, or utensils that have touched the cheese in a dishwasher, if possible. If you don’t have a dishwasher, use soap and hot water followed by a sanitizing solution of one tablespoon chlorine bleach mixed with one gallon of hot water.

If you ate the recalled cheese, watch for symptoms. They can appear within a few days of eating the contaminated cheese, but they sometimes take up to two months to develop, which can make it difficult to identify the source of the infection. If you do have symptoms, call your doctor and tell him or her that you ate the recalled cheese. Doctors use blood or spinal fluid tests to diagnose listeriosis, and they treat it with antibiotics, often given intravenously.

If you ate the cheese and don’t have any symptoms, the CDC says no testing or treatment is necessary.  

Which Foods Are Most Often Contaminated With Listeria?

In addition to soft cheeses and other dairy products, ready-to-eat refrigerated foods are also a potential source. In April 2015, the Centers for Disease Control and Prevention reported that between 2010 and 2015, 10 people had been hospitalized after becoming ill with several strains of listeria after eating Blue Bell’s ice cream products. In October 2016, Blue Bell also recalled its Chocolate Chip Cookie Dough and Cookie Two Step ice cream flavors due to possible listeria contamination from the cookie dough. And in September 2016, the Kellogg Company voluntarily recalled 10,000 cases of Eggo Nutri-Grain Whole Wheat Waffles, also because of a possible contamination.

Smoked seafood, pates, and meat spreads are also high-risk foods. Deli meats and hot dogs can be risky, too, unless they are cooked to an internal temperature of 165°F.

Fresh produce has been the source of listeria outbreaks, too. For example, raw bean sprouts were responsible for a 2014 listeria outbreak that killed two and sickened three people. (Sprouts require warm and humid growing conditions, which also are ideal for listeria growth, and rinsing sprouts doesn’t remove the bacteria.) In 2011, listeria-tainted whole cantaloupes from a single Colorado farm caused the deadliest U.S. foodborne disease outbreak in nearly 90 years, sickening 147 people in 28 states and killing 33. A federal investigation found unsanitary conditions at the farm’s processing facility, which was likely the reason the fruit was contaminated.

What Is Listeria Anyway? And How Does It Get Into Food?

Listeria monocytogenes is a bacterium found in soil, water, and decaying vegetation. Animals may carry it without appearing ill, and when those animals are processed for food, the resulting meat or dairy products can become contaminated.

Cross contamination from equipment or workers and poor hygiene are potential routes for listeria transmission.

As with salmonella and E. coli, pasteurization and cooking foods to the proper temperature kills listeria, but freezing doesn’t. So if food has been tainted with listeria (or another bacteria) before being frozen, the bacteria will survive, though they won’t increase in number. Once that food is defrosted, though, it’s subject to bacterial growth.

But listeria is different from other bacteria in one important way: it can continue to grow at refrigerator temperatures and can multiply rapidly, spreading from one food to another. Listeria also can live for years on equipment in places food is prepared, including food processing plants, grocery stores, and delis.

What Are the Odds of Being Infected With Listeria? How Serious Are the Health Risks?

The CDC estimates that there are 47.8 million cases of foodborne illness a year, and just over 3,000 deaths annually. Compared to other bacterial foodborne illness, listeria is rare, causing 1,600 cases and about 260 deaths a year.

Yet listeria is the third-leading cause of death from foodborne illness, according to the CDC. The majority of people who get sick from listeria end up being hospitalized, and the bug kills about one out of five people it infects.

Some groups of people should avoid high-risk foods because they are more likely to suffer from listeriosis and become severely ill. This includes people age 65 or older, who represent nearly 60 percent of cases. Also at higher risk are people of any age with weakened immune systems (including those undergoing chemotherapy or radiation) or conditions such as diabetes, alcoholism, and liver or kidney disease. In these groups, listeria often causes life-threatening bloodstream infections or meningitis.

Pregnant women are about 10 times more likely than the general population to be infected. Though the women themselves may experience only flu-like symptoms, listeria infections during pregnancy can cause miscarriages, stillbirths, or lethal illnesses in newborns.

Hispanic pregnant women are about twice as likely as other pregnant women to get listeriosis. The CDC says this is probably because soft cheeses like queso fresco are a big part of their diets. Queso fresco caused an outbreak of listeriosis in California in 1985 that sickened 142 people, causing 20 miscarriages as well as killing 10 newborns and 18 adults. Most of the victims were pregnant Latinas or their infants.

People who aren’t in any of these high-risk groups usually experience only mild gastrointestinal symptoms, or none at all, after eating listeria-contaminated foods, but some do suffer from the bug’s more severe health effects. For instance, among the 34 hospitalized victims of a 2014 outbreak linked to pre-packaged caramel apples sold at supermarkets in several states were three otherwise healthy children between the ages of five and 15 who developed meningitis.

After a Recall, What Do Companies Do to Make Sure Future Products Are Safe?

Identifying the source of the bacteria and eliminating it is essential and can require steps ranging from setting up new sanitizing systems in production facilities to establishing new listeria testing requirements.

For example, Snoqualmie Gourmet Ice Cream announced in late December 2014 that it was recalling all of its products produced during that year because they had been linked to two cases of listeriosis. The company then shut down its plant for a month to fully sanitize it. It also implemented new safety programs that required bacterial testing results from all of its suppliers, as well as third-party testing of its production facility and of all batches of ice cream prior to shipping, which was able to resume in late January 2015.

How Can I Make Sure the Food I Eat Is Safe in General?

While it’s largely up to food producers and retailers to make sure the foods you’re buying aren’t contaminated with listeria, taking the steps below will help cut your risks of infection:

Rinse raw fruits and vegetables thoroughly under running water using a clean vegetable brush scrub on those with thicker skins before cutting or eating. That even applies to foods with inedible peels like cantaloupe, to avoid spreading bacteria from the outside of the fruit to the flesh when you peel or cut it.

Keep your fridge below 40° F (our experts recommend 37° F) and your freezer no higher than 0° F. Use a refrigerator thermometer to check those temperatures regularly. Even small increases in temperature cause any listeria bacteria present to multiply much more quickly, according to Ben Chapman, associate professor and food safety specialist at North Carolina State University. For example, 100 listeria cells (the term used for measuring the amount of bacteria present) in a food can grow into 1,000 cells in about eight days in a refrigerator set at 41° F. At 45° F, it would only take four days for 100 cells to become 1,000 cells.

Limit storage time for refrigerated foods, especially opened ready-to-eat foods like deli salads and cut produce. Eat deli-sliced meats, or packaged luncheon meats that have been opened, within three to five days. Hot dogs, once their packaging is opened, should be used within a week.