Cheese Recalls as Map Shows US Listeria Outbreak

A growing number of products are being recalled by food manufacturers as they contain cheese from a California dairy producer thought by officials possibly to be behind a decade-long outbreak of listeria infections nationwide.

Nearly 60 food items containing queso fresco and cotija cheeses manufactured by Rizo-López Foods, of Modesto, California, have been recalled over fears they may have been contaminated with the potentially deadly bacteria.

An infection with listeria bacteria can cause a number of symptoms, with the worst affected usually being those with a weakened immune system, such as the elderly, pregnant women and newborns. Severe symptoms include miscarriages, stillbirths, seizures and death. Those less affected can still suffer from fever, headaches, fatigue, vomiting, diarrhea and confusion.

A map based on data compiled by the Centers for Disease Control and Prevention (CDC) shows the ongoing outbreak has so far been linked to 26 cases of illness across the U.S. There have been 23 hospitalizations and two deaths across 11 states—the largest proportion of cases occurring in California. One death due to listeria infection happened in California, while another occurred in Texas. The recalls, meanwhile, have covered products sold in almost every U.S. state.

The CDC said that the outbreak linked to the cheeses may not be limited to only those states where illnesses have been recorded and "the true number of sick people is likely higher;" some people who could have been infected may have recovered without medical intervention and were not tested for the bacteria.

"New recalls of food containing the cheeses are being added daily," a CDC spokesperson told Newsweek. "We don't know whether there will be more cases in this outbreak, but we are continuing to monitor for additional illnesses."

A Rizo-López Foods spokesperson told Newsweek last week: "As soon as we were aware of this, we made the immediate decision to stop production and voluntarily recall all our products manufactured in our facility.

"We are working hard and diligently to find the root cause of the problem and take corrective actions to prevent it from happening again," the spokesperson added. "The health and well-being of our customers is our top priority. We have always aimed to provide the highest-quality products and are committed to doing the right thing to protect the health of our consumers."

The cases linked to the outbreak range from June 15, 2014 to December 10, 2023—though the recall of all Rizo-López products did not occur until the start of February this year.

The CDC said this was because it initially investigated this outbreak in 2017 and 2021. While epidemiological evidence identified queso fresco and similar cheese as a potential source of the infections, there was insufficient evidence to point to a specific brand.

After new illnesses were reported in December, the CDC reopened the investigation in January. The strain of listeria particular to the outbreak was found in a cheese sample from Rizo-López in Hawaii, and then on a container at the company's facility where cheeses are kept before being packaged.

The CDC said that "recent illnesses may not yet be reported as it usually takes three to four weeks to determine if a sick person is part of an outbreak," suggesting the number of cases may yet rise further.

Information collected by public-health officials on the outbreak found the average age of those who have fallen ill is 52, and more women than men have been infected. Some 85 percent of those infected were of Hispanic ethnicity.

Update 2/16/24, 1:10 p.m. ET: This article was updated to include comment from a CDC spokesperson.