Whooping cough epidemic in California is worst in 70 years

SAN DIEGO -- California is battling the worst whooping cough epidemic recorded in the state in seven decades.

A total of 9,935 cases of whooping cough cases were reported to the California Department of Public Health from Jan. 1 to Nov. 26. That's the highest number in 70 years.

The vast majority of the cases -- 89 percent -- occurred in children under the age of 18. In one case, an infant died of the illness.

Whooping cough, also called pertussis, begins with cold-like symptoms and can progress to severe coughing fits.

State officials place much of the blame on a vaccine introduced in the 1990s that research has concluded doesn't last as long as the old one.

Another study suggests that while the vaccine may keep people from getting sick, it doesn't prevent them from spreading whooping cough to others.

The illness is cyclical, peaking every three to five years as immunity from the vaccine or previous outbreaks wanes. California's last epidemic was in 2010.