Guacamole and salsa may now be twice more likely to be tainted than it was prior to 1998, health regulators suggest.

"Fresh salsa and guacamole, especially those served in retail food establishments, may be important vehicles of food-borne infection," said Magdalena Kendall, an Oak Ridge Institute for Science and Education researcher, according to a statement released by the Centers for Disease Control and Prevention.

But not only restaurant guacamole is at risk.

“Salsa and guacamole often contain diced raw produce including hot peppers, tomatoes and cilantro, each of which has been implicated in past outbreaks” of food-borne illness, the CDC says.  And that includes those that may have been found in grocery store aisles.  Just this month, chili peppers were recalled on Salmonella fears, and last year, cilantro was recalled due to Salmonella contamination concerns as well.

Reports of salsa- and guacamole-related illnesses accounted for nearly 4% of outbreaks from food establishments from 1998 to 2008, according to the CDC. In the prior 10 years, they only accounted for 1.5%.

One major reason for the illnesses, which could affect consumers who buy the premade stuff and those who make their own at home as well, is that the lack of proper preparation and refrigeration can lead to contamination and the rapid growth of bacteria, the CDC says.

In restaurants and delis responsible for salsa and guacamole related illnesses, 30% of the facilities were reported to have inappropriate storage times or temperatures, according to the CDC.

Restaurants and delis may be particularly affected by contamination because guacamole and salsa are made in large batches and even a small amount of dangerous bacteria can grow quickly, especially at temperatures greater than 40 degrees Fahrenheit.