SAN RAFAEL, Calif. (KGO) -- Health officials are keeping a watchful eye for norovirus after six cases were reported in Marin County since October.
The latest outbreaks occurred this month. Several children got sick at a Jewish community center in San Rafael and a youth center in Novato.
Both facilities were shut down so they could be sanitized.
Norovirus is difficult to control once it gets established.
"The dose it takes to get infected gets very small. So, even just touching a contaminated surface and then touching your face is enough to be infected with norovirus," Marin Co. Public Health Officer Dr. Matt Willis said.
Hand washing is still the best defense against norovirus, which can cause vomiting and diarrhea.
This is still considered a typical year for norovirus in Marin County but California reports a spike statewide.