Listeria tied to soft cheese sickens 24, kills 1

A multistate Listeria outbreak linked to soft cheeses has sickened 24 people in nine states—21 seriously—killed 1 person, and resulted in a miscarriage, the Centers for Disease Control and Prevention (CDC) said today.

The outbreak involves five "rare DNA fingerprints" of the bacterium, the CDC said, and has led to a cheese recall. Some of the cases date back several years.

Five pregnant women infected

More than half of cases (14) have been in California, while New York has reported 2 cases and Colorado, Illinois, Massachusetts, Michigan, Ohio, Tennessee, and Washington state have all had 1.

The affected population skews older. Patients range in age from less than 1 year to 92, with a median age of 77. Five illnesses have been in pregnant women, including the one that resulted in a miscarriage. Listeriosis tends to affect the elderly, pregnant women, babies, and those with weakened immune symptoms. Eighteen of the patients are female.

Twenty-one of the cases required hospitalization, with the lone fatality reported in Ohio.

The earliest case dates from August 2010. Three cases occurred in 2012, 6 in 2013, 7 in 2014, and 7 this year. The person in the most recent case fell ill on Aug 24.

Fifteen of the patients (63%) are of Middle Eastern or Eastern European descent or shopped at Middle Eastern–style markets.

Cheese recall

Of 22 outbreak patients with available information, 18 reported eating soft cheeses before they became ill, and 16 specified Middle Eastern, Eastern European, Mediterranean, or Mexican-style cheeses, including ani, feta, Middle Eastern string cheese, and nabulsi.

Four of 7 patients who could name a brand reported eating cheese distributed by Karoun Dairies of San Fernando, Calif. No other brand was named more than once.

Two days ago that company announced a recall and ceased production of certain cheese because of possible Listeria contamination. Affected brands are Karoun, Arz, Gopi, Queso Del Valle, Central Valley Creamery, and Yanni. Products were sold in weights from 5 ounces to 30 pounds.

Karoun Dairies "is working closely with FDA to continue to investigate the problem further," the company said in a news release.

Genetic investigation

The outbreak was first brought to light last month when investigators noticed an uptick in one of the five rare Listeria "DNA fingerprints" that the CDC monitors via PulseNet, the national DNA database of foodborne pathogens, the agency said.

Illnesses caused by any of the other four strains, which are all closely related genetically, were added to the outbreak investigation. Additional cases possibly linked to the outbreak are under investigation, the CDC said.

See also:

Sep 18 CDC statement

Sep 16 Karoun Dairies recall notice

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