What is the California Department of Public Health doing about vibriosis?
The California Department of Public Health (CDPH) and local health departments monitor cases of vibriosis because Vibrio bacteria can easily contaminate the areas where shellfish (especially oysters) are grown and harvested, as well as areas where people recreate or spend time fishing, swimming, or wading in seawater. CDPH and local health and environmental departments monitor for outbreaks and investigate them to find a common source and take measures to prevent more people from getting sick.
When illness is associated with eating contaminated seafood, local environmental health staff investigate to find the source of the contaminated seafood. If an outbreak occurs, CDPH can remove contaminated seafood from the market, close California waters, and notify authorities from the states where shellfish are grown and harvested.
The CDPH Shellfish Program regularly monitors coastal and brackish waters in California where shellfish are grown and harvested to make sure that shellfish are safe for people to eat. More information on this program is available at the CDPH Shellfish Program webpage.
Levels of Vibrio bacteria are high in the Gulf of Mexico during the hot summer months, and many cases of vibriosis reported in the summer have been associated with eating raw oysters harvested from the Gulf. A 2003 regulation (PDF) prohibits the sale of raw oysters in California that have been harvested in the Gulf of Mexico during the summer months unless the oysters have been processed so that the levels of Vibrio vulnificus bacteria are not detectable. This has led to a marked decrease in the number of reported cases of severe vibriosis among California residents.