A Listeria outbreak in the Midwest linked to one death and a miscarriage likely was caused by contamination during the cheese-making process, according to a new report from the U.S. Centers for Disease Control and Prevention. “Inspection of the cheese-making facility revealed that substantial sanitation deficiencies during the cheese-making process itself, after the milk was pasteurized, likely led to contamination,” the agency’s April 4 Morbidity and Mortality Weekly report stated. The Listeria outbreak was first reported last summer and was linked to three types of Crave Brothers pasteurized soft cheese manufactured in Waterloo, WI. The cheeses – Les Frères, Petit Frère and Petit Frère with Truffles – were recalled as a result. One death related to the outbreak occurred in Minnesota, and Listerosis cases were reported in Minnesota, Ohio, Indiana and Illinois. The Minnesota Department of Agriculture tested samples of the cheese from two retail outlets, revealing the outbreak strain to be Listeria monocytogenes.

Even though pasteurization will eliminate Listeria bacteria in milk, contamination can still happen afterward, CDC noted. “Cheese-making facilities should use strict sanitation and microbiologic monitoring, regardless of whether they use pasteurized milk,” the report stated. Listeriosis primarily affects older adults, pregnant women, newborns and adults with compromised immune systems. Symptoms begin with fever and muscle aches and advance to stiff neck, confusion and loss of balance. More information on Listeria can be found here.