The Centers for Disease Control and Prevention (CDC) recently released a new study highlighting the increasing frequency of salsa and guacamole-based foodborne illness outbreaks.

This study, which was presented by the CDC at the International Conference on Emerging Infectious Diseases, analyzed all of the foodborne illness outbreaks since the CDC began keeping records in 1973.  For all salsa and guacamole lovers out there, the results are concerning.

Today one in 25 foodborne illness outbreaks are a direct result of the consumption of contaminated salsa or guacamole. Even more shocking is that these types of cases are on the rise. 

Between 1984 and 1997 salsa and guacamole accounted for only 1.5 percent of all cases, but between 1997 and 2008 the figure nearly doubled to 3.9 percent.  Most of the reported outbreaks were associated with restaurants, catering, and other food establishments.

The reason that salsa and guacamole are so susceptible to contamination is that they are made with multiple raw, uncooked vegetables and are often stored at room temperature. Tomatoes, cilantro, avocados, and peppers have all been linked to separate outbreaks in the past 10 years. These ingredients should be properly washed before preparation. 

“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,” says Magdalena Kendall, a researcher who worked with the CDC on the study.

Inadequate refrigeration was the cause of illness in 30 percent of the outbreaks since 1997.

Cross-contamination is also a common factor in salsa and guacamole outbreaks. Cross-contamination occurs when pathogens such as E. coli are transferred from a raw source to food about to be eaten.  Modes of transportation can include hands, knives, surfaces, and various kitchen appliances. 

This type of contamination can be avoided in part by enforcing proper hand washing guidelines.  Various studies, including one by North Carolina State University, show disappointing rates of hand washing in kitchen workers. This particular study found that kitchen workers were responsible for approximately 8 incidences of cross-contamination in an average work day.  In regards to salsa, this could occur after a worker uses a knife to cut up raw meat and then uses the same unwashed knife to chop up tomatoes for a fresh salsa. 

Practices leading to cross-contamination are widely regarded as dangerous. Most establishments make a special effort to avoid such behavior.

In twenty percent of salsa and guacamole outbreaks kitchen employees were responsible for contamination of the dipping sauces.