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"Smoking gun": Salmonella outbreak linked to irrigation water on a Mexican farm

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American



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Peppers were apparently the perps in the salmonella outbreak that sickened some 1,300 people in the U.S. and Canada since April. The Food and Drug Administration (FDA) announced that it traced the responsible bacterial strain—Salmonella Saintpaul—to a Serrano pepper grown on a Mexican farm that irrigated its fields with water contaminated with it.

The farm is located in Nuevo Leon, in northeastern Mexico, about 100 miles southwest of McAllen, Tex., where authorities last week found a salmonella-tainted jalapeño at a packing plant owned by Agricola Zarigosa. It traced that pepper back to a farm in Mexican state of Tamaulipas.

"We have a smoking gun, it appears," an official at the Centers for Disease Control and Prevention (CDC) told the Associated Press.

Government officials warned consumers last week not to eat fresh jalapeños and are now saying to nix related Serranos—but the advisory only covers peppers grown in Mexico.

Yesterday's announcement came while FDA's chief of food safety David Acheson was being questioned at a Congressional hearing. The subject of the inquiry was why tomatoes were originally implicated in the outbreak. From June 3 to July 17, the FDA had warned consumers to avoid eating raw, red tomatoes, but to date the fruit has not been directly linked to the illness outbreak.

Acheson told the lawmakers that tomatoes may have been linked to the early part of the outbreak, even though there is no hard evidence yet. According to the AP, however, the same contaminated irrigation water found on the Mexican farm was used on tomatoes, as well as peppers.

(Photo of Serrano pepper: iStockphoto/Robert Szajkowski)