Grocery loyalty cards help trace outbreaks - USATODAY.com
An outbreak of salmonella in five Eastern states has sickened 42 people so far this year, with two hospitalizations. Dozens more might have been struck down were it not for a strikingly successful new tool used by public health officials to quickly figure out what was making all those people sick: the lowly shopper-loyalty card.
Food safety officials are increasingly finding value in plumbing shoppers’ food buying habits through these loyalty cards when they’re faced with food-borne illness outbreaks across communities and even states that seem to have no obvious links.
“It’s very helpful because it’s very hard for people to remember what they ate a couple of days before, not to mention a couple of weeks ago,” says Casey Barton Behravesh, with the Centers for Disease Control and Prevention.
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Supermarket loyalty-card programs were introduced in 1987. By the 1990s, they were widely used. In return for discounts on some items, they allow companies to track shopping habits. For epidemiologists, who study disease outbreaks, they’re a complete record of everything shoppers bought at the store going back for years.
They “provide an accurate picture of a customer’s food history,” says Jeffrey Hammond, with the New York State Department of Health in Albany.
Privacy is a huge concern in using cards to track food-borne illness outbreaks, officials say. All health departments are required to get permission to use them, Hammond says. “This is voluntary: People are not required to consent to having the grocery chain release their shopper-card history,” he says.
And not all stores will supply records, even with written consent, Behravesh says.
But where health officials were granted access, they have found it a valuable evidence trail.