I spent most of the day yesterday in a car driving from Raleigh to Buffalo en route to Toronto. We’re making the migration for a hockey tournament that Jack is playing in and doing food safety stuff along the way. Like snapping pictures of handwashing signs.

Somewhere in Appalachia I chatted with Live Science’s Sara Miller about frozen foods, Listeria and stuff that’s not ready-to-eat.

Listeria can live for a really long time in the freezer, said Benjamin Chapman, a food-safety specialist and an associate professor at North Carolina State University.

In fact, freezing is how scientists preserve bacteria when they want to study the organisms in the lab, Chapman told Live Science.

While Listeria is not ubiquitous, it is very common in raw foods, Chapman said. Most people ingest some Listeria daily, but not in high amounts, and those individuals are fine, he said. It takes, on average, thousands of Listeria cells to make a person sick, he said.

But when Listeria does make someone sick, “it’s one of the most fatal pathogens we have,” Chapman said.

Several CDC reports of Listeria outbreaks found that the infection’s mortality rate was between 15 and 20 percent among people who became sick enough that they had to be hospitalized.

To protect yourself against Listeria, frozen vegetables should be cooked before they are eaten, Chapman said. Heating the foods kills Listeria, he said.

In fact, frozen vegetables are not considered “ready to eat” products, meaning that the foods should not be eaten raw, Chapman said. Though eating raw, frozen vegetables may sound unusual, frozen kale, for example, is increasingly being used in smoothies, he said. And it’s not uncommon for pediatricians to recommend letting young children chew and suck on frozen veggies while teething, he added.

Chapman noted that microwaving these foods is not the best way to prepare them. That’s because microwaves provide very uneven heat distribution, Chapman said. The food will get very hot in some places and not hot in other places, he said. In other words, the bacteria might not be killed throughout the food.

He also recommended avoiding thawing frozen vegetables in the refrigerator. This can be risky, especially if a person leaves the food in the refrigerator for multiple days, he said. (sort of, this one didn’t translate very well as I was traveling through a mountain tunnel- thawing in the fridge is cool, leaving uncooked thawed frozen veggies in the fridge for a long time – like a week – especially if the temp is above 41F isn’t great -ben).

A tour through the FDA recall listings shows a bunch of Listeria-sparked recalls of frozen foods that are intended to be cooked before consumption.

But consumers are unpredictable.

Frozen kale is a popular smoothie ingredient.

Frozen edamame is a favorite snack of one of my friends.

My pediatrician recommended letting my son chew on frozen peas, corn and carrots when teething.

What once was thought to be not-ready-to-eat is increasingly treated as ready-to-eat in homes and restaurants.

CDC the details of 8 cases of listeriosis linked to CRF Frozen Foods of Pasco, Washington.

A total of eight people infected with the outbreak strains of Listeria have been reported from three states since September 13, 2013. A list of states and the number of cases in each can be found on the Case Count Map page.

Listeria specimens were collected from September 13, 2013 to March 28, 2016. Two illnesses were reported in 2016. The remaining six illnesses reported during 2013-2015 were identified through a retrospective review of the PulseNet database. Ill people range in age from 56 years to 86, with a median age of 76. Seventy-five percent of ill people are female. All eight (100%) ill people were hospitalized, including one from Maryland and one from Washington who died, although listeriosis was not considered to be a cause of death for either person.

Epidemiologic and laboratory evidence available at this time indicates that frozen vegetables produced by CRF Frozen Foods of Pasco, Washington and sold under various brand names are one likely source of illnesses in this outbreak. This is a complex, ongoing investigation, and updates will be provided when more information is available.

This outbreak was identified in March 2016. State and local health departments attempted to interview the ill people, a family member, or a caregiver for the ill person about the foods the ill person may have eaten in the month before the illness began. Three of eight ill people, or their caregiver, were interviewed using a questionnaire that asked about a variety of foods. Two of these three people reported buying and eating frozen vegetables in the month before illness began and both reported Organic by Nature brand frozen vegetables. Organic by Nature frozen vegetables are produced by CRF Frozen Foods.

During the same time period, as part of a routine product-sampling program, the Ohio Department of Agriculture collected packages of frozen vegetable products from a retail location and isolated Listeria from True Goodness by Meijer brand frozen organic white sweet cut corn and from True Goodness by Meijer brand frozen organic petite green peas. Both products were produced by CRF Frozen Foods. Whole genome sequencing showed that the Listeria isolate from the frozen corn was closely related genetically to seven bacterial isolates from ill people, and the Listeria isolate from the frozen peas was closely related genetically to one isolate from an ill person. This close genetic relationship provides additional evidence that some people in this outbreak became ill from eating frozen vegetables produced by CRF Frozen Foods.

On April 23, 2016, CRF Frozen Foods recalled 11 frozen vegetable products because they may be contaminated with Listeria. On May 2, 2016, CRF Frozen Foods expanded the initial recall to include all organic and traditional frozen vegetable and fruit products processed in its Pasco, Washington facility since May 1, 2014.