Why Does It Seem Like There Are So Many Listeria Outbreaks?
By now, you've probably heard that dozens of cheeses have been recalled across the country after a manufacturer reported the possibility of listeria contamination in its Tennessee production facility. And that's hardly been the only well-documented case in recent years. But why are we so afraid of listeria—and is the bacterium more prevalent today than it has been in the past?
Listeria is bacterium that grows in foods stored at refrigeration temperature—40 degrees Fahrenheit—such as chopped lettuce, deli meats, and, of course, cheese. It can cause meningitis, septicemia, abortion, and even death when ingested. In fact, up to 20 percent of people with listeriosis die. Listeriosis is the third most deadly food borne illness, causing some 260 deaths each year, the CDC estimates.
Yet even with those startling stats—and even in light of what feels like the great cheese recall of 2017—cases of listeriosis are decreasing across the country. That's thanks in part to new sanitation and food safety measures across the industry that have reduced and controlled listeria outbreaks, says Michael Doyle, regents professor of food microbiology at the University of Georgia's Center for Food Safety.
So why does it feel as if we're faced with a listeria outbreak or a recall notice every time we turn on the news? "The CDC and FDA have had a major initiative focused on listeriosis using advanced outbreak detection tools," says Doyle. The GenomeTrakr, as it's called, uses whole genome sequencing to identify pathogens and shares the data amongst researchers and public health officials who can initiate and oversee outbreak investigations, as well as reduce foodborne illnesses and deaths.
"This has resulted in detecting more outbreaks of listeriosis that would likely have been unrecognized if these advanced methods were not used," explains Doyle. In other words, we hear about listeria more often because of GenomeTrakr, but we're also better equipped to prevent listeriosis and its consequences because of it.
If that sounds like a good thing, it is—and that's why this tool will soon be applied to salmonella, campylobacter, and pathogenic E. coli outbreak surveillance, Doyle says, which will, of course, mean more news about those foodborne illnesses too.