Don’t Forget the Epidemiology: Unraveling a Five-Year Listeria Outbreak

September 28, 2015

It’s not every day that you see an outbreak of foodborne illness spanning five years. But that’s what happened with a Listeria outbreak first announced 10 days ago by the Centers for Disease Control and Prevention (CDC).

Just last month, it was whole-genome sequencing that connected together the 24 illnesses reaching back to 2010. But good old-fashioned epidemiology is what tracked down the source — soft cheeses produced by Karoun Dairies of San Fernando, CA.

Soft cheeses are not an unexpected source of Listeria infections, but some of the specific types linked to this outbreak weren’t familiar to investigators.

Eighteen victims said…