The Hidden Time Bomb In Queso Fresco Cheeses

February 9, 2009

Late last month, three pregnant Illinois women developed listeriosis after consuming different types of soft cheeses made from raw milk. The three women all were infected with the same strain of Listeria monocytogenes, suggesting that the various cheeses all were made from the same milk source.

All three women transmitted their infection to their infants during their pregnancy. Two of the women miscarried; the third gave birth to a baby that was infected with Listeria monocytogenes.

Coincidentally, the New York State Department of Agriculture and Markets warned the public last week against consuming a specific batch code of Queso Fresco produced by Peregrina Cheese Corp. (342 Ten Eyck St., Brooklyn, NY 11206) after detecting Listeria monocytogenes in a sample of the cheese.

As a result of the State's finding, Peregrina Cheese has agreed to recall 14-ounce packages identified with batch code 4461.

This is the second time in 15 months that Peregrina has recalled Queso Fresco after New York State found Listeria monocytogenes in a sample. The previous recall, which took place in December 2007, also involved just a single batch code.

Listeria monocytogenes typically causes no more than mild gastrointestinal or flu-like illness in most individuals. But people with weakened immune systems, the elderly, and the very young are at risk of suffering life-threatening symptoms. 

Pregnant women, while often only suffering mild symptoms, often pass the Listeria monocytogenes infection to their infants in utero. Too often – as happened in Illinois – this results in premature birth, a stillbirth, or the birth of a seriously ill baby.

To minimize the risk of contracting an infection with Listeria monocytogenes, pregnant women should avoid foods – notably soft cheeses, raw milk, other unpasteurized dairy products, ready-to-eat deli meats and smoked fish – that are especially likely to be contaminated with this pathogen.