For every 25 outbreaks of food-borne disease linked to restaurants, nearly one incidence resulted from contaminated salsa or guacamole, according to research the U.S. Centers for Disease Control and Prevention (CDC) presented at the International Conference on Emerging Infectious Diseases.

To determine how these snacks triggered food illnesses, researchers from the Oak Ridge Institute for Science and Education (ORISE) examined all food-borne disease outbreaks recently reported to the CDC. Scientists concentrated on reports focusing suspicion on salsa, guacamole or pico de gallo. Then researchers analyzed the proportion of outbreaks with food sources.

Researchers found that salsa- or guacamole-associated outbreaks accounted for almost 4 percent of all reported incidents from 1998 to 2008. (Such outbreaks accounted for 1.5 percent from 1984 to 1997.)

“Possible reasons salsa and guacamole can pose a risk for food-borne illness is that they may not be refrigerated appropriately and are often made in large batches, so even a small amount of contamination can affect many customers,” said Magdalena Kendall, an ORISE researcher.

Other food contamination causes included inappropriate storage times or temperatures, unhygienic food workers and the use of raw produce, such as hot peppers, tomatoes and cilantro—ingredients previously identified in other disease outbreaks.

“We want restaurants and anyone preparing fresh salsa and guacamole at home to be aware that these foods containing raw ingredients should be carefully prepared and refrigerated to help prevent illness,” Kendall says. “Awareness…is key to preventing future outbreaks.”

Safe preparation and proper storage of fresh salsa and guacamole can lower contamination and pathogen growth risk, the CDC said.

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