(Eugene, OR)  --  Health officials say at least ten people have been affected by a whooping cough outbreak in Eugene.  All of the reported cases have been from Sheldon High School, and the number is expected to rise.  Whooping cough is a respiratory tract infection that can be deadly for infants and babies, and is preventable by vaccine.  A doctor from Eugene's Lane County Public Health says one case of it can produce 15 new ones.  Students from Sheldon High who have not been vaccinated have been excused from class, and school and health officials are working together to contain the outbreak.