A norovirus outbreak has sickened 39 residents and staff at a senior community in Tacoma.

Staff at Narrows Glen reported the outbreak to Tacoma-Pierce County Health Department after symptoms were first noticed on Thursday.

Narrows Glen officials said as of Tuesday, 11 residents and nine staff members were still ill.

Health officials say symptoms of the easily spread disease can include diarrhea, vomiting, nausea and stomach pains. They can start 12 hours to 48 hours after exposure.

Norovirus is highly contagious and spreads easily from person to person. Proper handwashing is the best defense against it. No specific treatment for norovirus exists.