Salsa, guacamole growing sources of foodborne illnesses

ATLANTA — Salsa and guacamole were responsible for many gastrointestinal illness outbreaks between 1998 and 2008, according to data presented here at the 2010 International Conference on Emerging Infectious Diseases.

“Fresh salsa and guacamole, especially those served in retail establishments, may be important vehicles of foodborne infection,” study researcher Magdalena Kendall, of the CDC and Oak Ridge Institute for Science and Education, said in a press release. “Salsa and guacamole often contain diced raw produce, including hot peppers, tomatoes and cilantro, each of which has been implicated in past outbreaks.”

Kendall and other CDC researchers reviewed foodborne outbreaks reported to the CDC that cited salsa, guacamole or pico de gallo as the confirmed or suspected sources. They analyzed data on outbreak frequency and size, pathogens, patient demographics, settings and reported contributing factors. Outbreaks were categorized as occurring in food establishments if they originated in restaurants, delis or similar settings.

Surveillance on foodborne disease outbreaks began in 1973, although neither salsa nor guacamole was implicated in any cases until 1984, according to the researchers. Results indicated that 136 restaurant outbreaks were attributable to either food between 1984 and 2008, with salsa acting as the causal agent in 95 cases, guacamole in 36 cases and both in five cases. Eighty-five percent of all outbreaks happened in food establishments, they noted.

Of all 5,560 illnesses resulting from salsa and guacamole outbreaks, Salmonella was the causative agent 33% of the time; norovirus, 18%; Shigella, 15%; and other pathogens, 10%. Etiology could not be determined in 24% of illnesses. One hundred forty-five hospitalizations and three deaths were related to these infections, the researchers said.

The proportion of food establishment outbreaks related to salsa and guacamole rose from 1.6% during 1984 to 1998 to 4.1% between 1999 and 2008.

The researchers identified barehanded food handling, infected food worker handling, contaminated equipment, cross-contamination and room temperature storage as the major contributing factors to salsa- and guacamole-related outbreaks and disease cases. They noted that these issues can easily be avoided by taking the proper precautions when preparing these foods.

“We want restaurants and anyone preparing fresh salsa and guacamole at home to be aware that foods containing raw ingredients should be carefully prepared and refrigerated to help prevent illness,” Kendall said. – by Melissa Foster

For more information:

Kendall ME. #12. Presented at: 2010 International Conference on Emerging Infectious Diseases; July 11-14, 2010; Atlanta.