A Listeria outbreak linked to soft cheeses has sickened 24 people, killing one of them and causing one miscarriage, according to the Centers for Disease Control and Prevention (CDC). The cases, reported from nine states over a five-year period, are associated with cheeses produced by Karoun Dairies, Inc. of San Fernando, California which have been recalled.
The recalled products are vacuum packed, in jars or in pails under the brands: Karoun, Arz, Gopi, Queso Del Valle, Central Valley Creamery, Gopi, and Yanni. Weights vary from 5 ounces to 30 pounds. They were distributed to nationwide to grocery stores and food service accounts. Two of the stores that carried the recalled products are Publix and Sam’s Club.
Consumers who have purchased these cheese should not eat them as Listeria can cause serious illness and death. (The recalled products are listed in Karoun Dairies link above.) 
This outbreak includes five rare DNA fingerprints of Listeria. Health investigators used whole genome sequencing (WGS) to identify 24 cases from nine states since August 8, 2010. By state, the case count is as follows: California (14), Colorado (1), Illinois (1), Massachusetts (2), Michigan (1), New York (2), Ohio (1), Tennessee (1), and Washington (1).
Twenty-one people were hospitalized. Five of the cases were pregnancy-related, one them resulted in a miscarriage. The death was reported from Ohio.
Those at high risk of Listeria infections are young children, seniors, those with compromised immune systems and pregnant women. Symptoms of an infection include high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea.
The CDC says the “investigation has not conclusively identified the source of this outbreak, but most ill people interviewed reported eating soft cheese before becoming ill.” Eighteen of 22 case patients interviewed reported eating soft cheeses in the month before becoming ill. Four of them mentioned brands made by Karoun Dairies. No other brand of cheese was reported more than once, according to the CDC.
CDC, the U.S. Food and Drug Administration (FDA) and state health officials are using PulseNet, the national subtyping network, to identify illnesses that may be part of this outbreak. When Listeria cases are diagnosed, a test to identify its DNA fingerprint is performed using pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). These fingerprints are then uploaded to PulseNet.
This outbreak was identified in August 2015 after investigators saw an increase in one of the five rare PFGE fingerprints reported to PulseNet. Because WGS showed the five fingerprints are closely related genetically, investigators were able to link cases from August 8, 2010 to August 24, 2015. Additional illnesses are under investigation.
The case patients in this outbreak range in age from less than 1 year to 92. The median age is 77. Seventy-five percent of ill people are female. Fifteen are of Middle Eastern or Eastern European descent or shopped at Middle Eastern-style markets.
Of 22 cases patients for whom information is available, 82 percent said they consumed soft cheeses, 89 percent reported eating Middle Eastern, Eastern European, Mediterranean, or Mexican-style cheeses, including ani, feta (including Bulgarian feta), Middle Eastern-style string cheese, and nabulsi. The investigation is ongoing.
