The CDC reports that between 1998 and 2008, freshly prepared salsa and guacamole have accounted for nearly one out of every 25 cases of deli and restaurant foodborne illness outbreaks. The most common microbe found in the mishandled condiments – which were often refrigerated improperly — was norovirus, which can cause diarrhea, vomiting, and stomach pain. The director of the University of Georgia’s Center for Food Safety, Michael Doyle, offered advice on how to prevent contamination:
Refrigeration is the key to safe salsa…An unusual finding was if you used fresh garlic and fresh lime juice, it prevented the growth of bacteria. You couldn't use powdered, it had to be fresh.
ACSH's Dr. Gilbert Ross recommends that consumers “be discriminating about where they order their fresh guacamole and salsa. I advise those that make guacamole and salsa wash their hands and/or use gloves and be sure to immediately refrigerate it.”