At least 25 E. coli illnesses in residents of New Mexico, Arizona, Colorado, Nevada, and California have been linked to Bravo Farms Dutch Style Gouda Cheese sold or offered at Costco during the "cheese road show" between October 5 and November 1.  Yesterday, the CDC released its first investigative summary on the outbreak:

Investigation of the Outbreak

CDC is collaborating with public health officials in Arizona, California, Colorado, New Mexico, Nevada, the U.S. Department of Health and Human Services’ Food and Drug Administration (FDA), and the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) to investigate a multistate outbreak of human infections due to E. coli O157:H7 (E. coli 0157:H7). This is a rare strain of E. coli O157:H7 that has never been seen before in the PulseNet database. PulseNet is the national subtyping network made up of state and local public health laboratories and federal food regulatory laboratories that performs molecular surveillance of foodborne infections.

Twenty-five persons infected with the outbreak strain of E. coli O157:H7 have been reported from five states. The number of ill persons identified in each state with this strain is as follows: AZ (11), CA (1), CO (8), NM (3) and NV (2). Dates of illness onset range from October 16, 2010 through October 24, 2010. Patients range in age from 2 to 81 years and the median age is 14 years.

The outbreak can be visually described with a chart showing the number of persons who became ill each day. This chart is called an epidemic curve or epi curve. Illnesses that occurred after October 18, 2010 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 3 weeks.

Current Status of the Investigation

Preliminary laboratory testing conducted on an opened package of Bravo Farms Dutch Style Gouda Cheese purchased at Costco from a case patient’s home has indicated the presence of E. coli O157:H7. Additional laboratory testing is currently ongoing to confirm this result.

Additional investigative activities are ongoing and include:

  • Conducting surveillance for additional illnesses that could be related to the outbreak.
  • Conducting epidemiologic studies that include collecting detailed information from ill persons (cases) and from healthy persons (controls) about foods recently eaten and other exposures.
  • Gathering and testing food products that are suspected as possible sources of infection to see if they are contaminated with bacteria.
  • Following epidemiologic leads gathered from interviews with patients, food purchase information, or from patterns of processing, production and/or distribution of suspected products.
  • Investigating where in the distribution chain the point of contamination could have occurred.