This is not a local outbreak. In fact, it is relatively widespread in this region and in California. The agent, norovirus, is the same one responsible for outbreaks on cruise ships. The mode of transmission is person-to-person, touching contaminated surfaces and objects, or by contaminated food or water.

Personal and environmental hygiene are very important to minimize the transmission of this virus. Good hand hygiene includes thorough hand washing; alcohol-based hand cleansers are also important. Sanitizing surfaces can be difficult for this agent. A 1:10 dilution of bleach works best. However, bleach is corrosive to metal surfaces.

Attached is a document prepared by the Centers for Disease Control and Prevention regarding norovirus.