EL SOBRANTE, Calif. (AP) -- A school in Contra Costa County was closed Friday because of an outbreak of whooping cough.

A notice posted on the doors of the East Bay Waldorf School in El Sobrante says the school will be closed for the day because of the outbreak involving kindergarten students and teachers.

Contra Costa County health officials plan to release more information about the school closure during a media briefing this morning.

Whooping cough -- or pertussis -- is considered highly contagious. Symptoms include a prolonged cough that ends in a whooping sound when the person takes a breath.