Shopper cards used to track salmonella source

March 11, 2010 at 12:00a.m.

Associated Press

CHAMPAIGN, Ill.

As they scrambled recently to trace the source of a salmonella outbreak that has sickened hundreds around the country, investigators from the Centers for Disease Control and Prevention successfully used a new tool for the first time — the shopper cards that millions of Americans swipe every time they buy groceries.

With permission from the patients, investigators followed the trail of grocery purchases to a Rhode Island company that makes salami, then zeroed in on the pepper used to season the meat.

Never before had the CDC successfully mined the mountain of data that supermarket chains compile.

“It was really exciting. It was a break in the investigation for sure,” CDC epidemiologist Casey Barton Behravesh said.

At least 245 people in 44 states have been sickened in the outbreak. That includes 30 in California, 19 in Illinois, 18 in New York and 17 in Washington state.

Shopper cards have been around for more than a decade, offering customers discounts in exchange for letting supermarkets track their buying habits. The cards are used to build customer loyalty and help stores market their products.

The first case in this salmonella outbreak was reported last summer, and by November, CDC investigators were examining a multistate cluster of cases.