It’s been a very busy year for food recalls in the United States. The U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) have announced several recalls in recent months for everything from ice cream And waffles Unpleasant fresh products and even millions of pounds of deli meat.

And they all had one thing in common: they were caused by the fear of possible contamination with Listeria monocytogenes, a bacterium that can cause serious and sometimes fatal infections.

The deadliest outbreak yet – with 10 deaths – has been linked to a Boar’s Head meat plant in Virginia. More recently, BrucePac, an Oklahoma-based producer of pre-cooked meat, almost recalled this month 10 million pounds of products sold in the country’s largest supermarket chains, including Walmart (WMT+1.51%), Kroger (KR+0.15%), 7-Eleven (SVNDY-1.28%), and Trader Joe’s

The apparent increase in listeria-related recalls is concerning. Listeria monocytogenes can cause serious listeriosis infections in young children, the elderly, and people with weakened immune systems. The FDA also warns that listeria infections can cause miscarriages and stillbirths in pregnant women. Even in healthy people, a listeria infection can lead to symptoms such as high fever, headache, stiffness, nausea, abdominal pain and diarrhea.

An approximate one 1,600 people in the US get listeriosis every yearwith about 260 fatalities annually, according to the U.S. Centers for Disease Control and Prevention.

So why does the number of listeria infections seem to be increasing?

“What we are seeing is likely a perfect storm of factors: regulatory transitions, pandemic-related inspection gaps, increased detection capabilities and economic pressures. Together, these elements have led to an increase in the number of recalls.” Dr. Darin Detwiler, a food safety consultant and professor at Northeastern University, told Quartz in an email. “While it is unclear whether one specific issue is driving the trend, the combination suggests there are vulnerabilities within the food regulatory system that need to be addressed to restore consumer confidence.”

Better and more accurate detection

One reason recalls appear to be increasing is improvements in testing technology. For example, Detwiler said the widespread use of whole genome sequencing, a process for analyzing an organism’s DNA, makes it easier to detect pathogens such as Listeria.

“These advanced methods can track contamination more effectively, leading to faster recalls,” Detwiler said. “This may give the impression that recalls are becoming more common, when in reality we are simply identifying contamination more efficiently than before.”

An increasing demand for ready-made food products

However, it’s not just better testing that’s leading to all these recalls. The recalls may also reflect a shift in consumer preferences and production methods.

Detwiler pointed out that consumers generally rely more on convenience food products such as deli meats, cheese, salads and pre-cooked meats. These products are often stored in refrigerators or freezers.

Unfortunately, unlike other pathogens, Listeria can thrive in cold environments.

“Most of these products often have a long shelf life, giving Listeria more time to grow even if initial contamination levels are low,” Detwiler said.

In addition, the complexity of the global food supply chain, with ingredients sourced from different places around the world, makes it more difficult to trace the source of a contamination. It also adds more steps to the production of the product, increasing the risk of cross-contamination.

Gaps in inspections

Finally, another possible factor that could be contributing to what appears to be an increase in listeria-related food recalls could be a combination of a recent FDA restructuring and a reduction in in-person inspections during the COVID-19 pandemic.

The FDA announced reorganization plans last year. This month, the regulatory agency announced the creation of a new Human Food Program, a new model and a new name for its field operations. The government said it is the largest reorganization in the agency’s recent history, affecting more than 8,000 employees.

Detwiler said this transition phase “can often create temporary gaps in oversight or slower response times to emerging food safety risks.”

At the same time, the number of personal contacts is reduced suspension and reduction of personal inspections during the COVID-19 pandemic could have potentially led to “lapses in sanitation and food safety compliance.”

For example, Boar’s Head closed in September “indefinitely‘his deli in Virginia, which is linked to a fatal listeria outbreak. The closure came after federal inspectors reportedly discovered dozens of violations in the facility, including mold, puddles and the presence of insects near food.

Even before the pandemic, the USDA has completed a new one The rule allowed pig slaughterhouses to hire their own inspectors.