Thirty-seven people have now been confirmed as infected with an outbreak strain of E. coli O157:H7 traced to Bravo Farms Dutch Style Gouda Cheese served and sold at Costco Warehouses in five states.

The Centers for Disease Control and Prevention said the latest four cases were reported in Arizona, where 19 people have been sickened so far as a result of eating the raw milk cheese. 

The number of ill people identified in other states with this strain is as follows:  three in California, 10 in Colorado, 3 in New Mexico and 2 in Nevada.  Fifteen people required hospitalization and one person developed hemolytic uremic syndrome (HUS).

According to the CDC investigation summary, laboratory testing identified E. coli O157:H7 matching the outbreak strain in two opened packages of Bravo Farms Dutch Style Gouda Cheese purchased at Costco by two different case patients.

Preliminary lab testing conducted on two additional opened packages of the cheese from two other patients’ homes also indicated the presence of E. coli O157:H7. Additional testing is being done to confirm those results.

In addition, preliminary testing conducted on a unopened package of Bravo Farms Gouda cheese obtained from a Costco store has identified E. coli O157:H7, the CDC reported.

The U.S. Food and Drug Administration is working with state health authorities to investigate Bravo Farms and to discover potential sources of contamination.  FDA has collected product samples for testing.