Yesterday, a company called Del Bueno, of Grandview, Washington, recalled queso fresco cheese products due to potential listeria contamination.  The recall was initiated after routine samping by the Washington State Department of Agriculture detected the presence of listeria monocytogenes in the cheese products, but the Dept. of Ag. also stated today that an illness has been linked to the contaminated cheese. 

Queso fresco is a mexican soft cheese made that is not pasteurized.  As a result, it poses a heightened risk of illness for pregnant women.  The reason, of course, is that the lack of pasteurization means that the product is subjected to no kill step that will eradicate any viable bacterial contamination on the product. 

Queso fresco contaminated by listeria monocytogenes has long been a recognized risk for pregnant women, and it has also caused many very unfortunate illnesses and deaths.  In January 2009, the Illinois Department of Public Health announced that:

Three pregnant Hispanic women in Chicago and suburban Cook County tested positive for listeriosis after becoming ill in late November and December. All three women report eating different types of soft cheese. One woman delivered her baby who also tested positive for listeriosis, but the other two women suffered miscarriages.

Health organizations and the government publish a lot of informaiton on the risks that raw, unpasteurized foods pose to the consuming public in general, and especially to pregnant women.  The Mayo Clinic offers a detailed set of guidelines for pregnant women deciding whether to consume raw foods.  The foods advised against include queso fresco and other unpasteurized cheeses, seafood potentially high in mercury, raw or undercooked seafood, and raw or undercooked meat, poultry and eggs.  I would add raw milk to the list as well.  Whatever the case, pregnant women are estimated to be at a 20 times higher risk of illness, and severe illness, by consuming raw foods.