Melissa Plantenga, who tracks food-borne diseases for the Oregon Department of Human Services, detected a pattern that would force Los Angeles-based Paramount Farms Inc., the nation’s largest almond grower, to recall 13 million pounds of almonds over the last week, equivalent to about a quarter of its annual production.
Soon after the Department started receiving calls about illnesses, she, armed with a 400-question survey, started calling the five Oregon residents who had been stricken with salmonella poisoning, according to the Los Angeles Times.
By the third call, Platenga learned that the victims had all eaten shelled raw almonds purchased at a Costco Wholesale Corp. store. Costco’s ability to use membership numbers to track every purchase helped confirm Plantenga’s deduction.
After learning of the recall, Costco sent more than 1 million letters to customers who purchased the almonds asking them to return any remaining nuts, a Costco spokesman said.
Using Costco’s data, investigators traced the nuts back to Paramount Farms.
California farmers supply about 80% of the world’s almonds, up from 60% a decade ago, growth fueled in part by opening up new markets, such as India and Eastern Europe. The recall — the largest ever of California almonds — has roiled the state’s $1.2-billion industry.
Paramount Farms has started to sterilize all its raw almonds with propylene oxide gas.
Doug Youngdahl of Blue Diamond said that some method of pasteurization or sterilization should become the industry standard for raw nuts.
It is a prudent move, he said, considering that the nuts are harvested by shaking the tree until they fall to the ground, where there can be microbes and other germs.
“No one wants to sell a product that makes the customer sick,” Youngdahl said.