The number of whooping cough cases in California has reached epidemic proportions.
The California Department of Public Health announced Friday there have been 800 cases of pertussis in just the past two weeks. California already has had more cases this year than all of last year - about 3,458 cases as of June 10.
Infants are especially susceptible to the diseases, which can be fatal. Parents are urged to vaccinate their newborns as soon as possible.
Whooping cough is a highly contagious bacterial disease that starts with cold-like symptoms and leads to coughing fits. Infants too young to be vaccinated are at the greatest risk of contracting it.
The Associated Press contributed to this report.
Whooping cough cases reach epidemic proportions