CDC began conducting surveillance for foodborne disease outbreaks began in 1973, yet no salsa- or guacamole-associated (SGA) outbreaks were reported before 1984. Restaurants and delis were the settings for 84 percent of the 136 SGA outbreaks. SGA outbreaks accounted for 1.5 percent of all food establishment outbreaks from 1984 to 1997. This figure more than doubled to 3.9 percent during the ten-year period from 1998 to 2008.
Inappropriate storage times or temperatures were reported in 30 percent of the SGA outbreaks in restaurants or delis and may have contributed to the outbreaks. Food workers were reported as the source of contamination in 20 percent of the restaurant outbreaks. Also, salsa and guacamole often contain diced raw produce including hot peppers, tomatoes and cilantro, each of which has been implicated in past outbreaks.
The 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. Risk can be lowered by following guidelines for safe preparation and storage of fresh salsa and guacamole to reduce contamination or pathogen growth.
Fuente CDC http://www.cdc.gov/media/pressrel/2010/r100712.htm