OK, I know the economy is bad – but bad enough to eat pet food?

The CDC reported yesterday that as early as May 16, 2008, it reported on a 2006–2007 multistate outbreak of infection with Salmonella enterica serotype Schwarzengrund that was associated with dry dog food. At the time of that report, a total of 70 cases had been reported from 19 states, with the last case identified on October 1, 2007. Subsequently, an additional case was identified on December 29, 2007. Epidemiologic and environmental investigations suggested the source of the outbreak was dry pet food produced by one manufacturer, Mars Petcare US. In 2008, eight more cases were reported, bringing the total number of cases in the outbreak to 79. On September 12, 2008, the company announced a nationwide voluntary recall of all dry dog and cat food products produced during a 5-month period at one Pennsylvania plant.

During 2006–2007, CDC, the Food and Drug Administration (FDA), and multiple state health departments investigated reports to PulseNet† of persons infected with a strain of S. Schwarzengrund with an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern. Investigators initially identified 70 cases, mostly in children. As a result of these findings, on August 21, 2007, Mars Petcare US announced voluntary recalls of selected sized bags of two brands of dry dog food, both manufactured by the company at its plant in Everson, Pennsylvania. The recall was based on microbiologic testing by FDA, which found unopened bags of the two brands contaminated with the outbreak strain. The Everson, Pennsylvania, facility ceased operations during July–November 2007 to enable cleaning, disinfection, and renovation, and resumed normal operations in mid-November 2007.

Despite the 2007 recall, the outbreak strain of S. Schwarzengrund was isolated from eight more ill persons during January–October 2008, bringing the total number of cases to 79 in 21 states. The last reported specimen collection date was September 18, 2008.

After additional outbreak-linked illnesses were identified in 2008, FDA conducted another investigation. In August 2008, FDA found the outbreak strain of S. Schwarzengrund in multiple brands of finished product at the plant, prompting another recall of products by Mars Petcare US. On September 12, the company announced a nationwide voluntary recall of all dry dog and cat food products produced at the Everson plant from February 18 to July 29, 2008, when production again was suspended at the plant. In addition, Mars Petcare US has taken steps to ensure that recalled products are no longer on store shelves. On October 1, the company announced that the Everson plant would be closed permanently.