In the last two decades, the number of Americans noshing on salsa and guacamole at restaurants has soared. Unfortunately, so has the number of Americans getting sick from salsa and guacamole they eat at restaurants.

According to a newly released study by the Centers for Disease Control and the Oak Ridge Institute for Science and Education, the number of restaurant-associated foodborne outbreaks between 1998 and 2008 was more than double that of the previous 13 years.

According to the CDC, which actually has an acronym — “SGA” — for salsa- or guacamole-associated outbreaks, there had been no SGA outbreaks reported before 1984. Between 1984-1997, SGA outbreaks only accounted for 1.5% of all food establishment outbreaks. But then, between 1998-2008, that number rocketed up to 3.9%.

Researchers say some of the cause is simply related to the nature of these dishes:

Fresh salsa and guacamole, especially those served in retail food establishments, may be important vehicles of foodborne infection… Salsa and guacamole often contain diced raw produce including hot peppers, tomatoes and cilantro, each of which has been implicated in past outbreaks.

But it’s not just the ingredients. There’s also human error. The study found that 30% of the cases involved inappropriate storage times or temperatures. And then there’s the 20% of cases where the workers themselves were the source of contamination.

More from the researchers:

Possible reasons salsa and guacamole can pose a risk for foodborne 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… Awareness that salsa and guacamole can transmit foodborne illness, particularly in restaurants, is key to preventing future 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.

Salsa and Guacamole Increasingly Important Causes of Foodborne Disease [CDC]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.