San Diego County health officials say a month-old baby boy has died of whooping cough.

The death reported Thursday marks at least the seventh infant to die of whooping cough this year in California.

The San Diego County Health and Human Services Agency says the boy died Tuesday at Rady Children's Hospital, the county's first whooping cough death in nine years.

Whooping cough has become an epidemic in California, which has recorded about 1,500 cases through July 13. That's a fivefold increase over the same period last year.

Dean Sidelinger, county deputy public health officer, urges parents and caretakers to get vaccinations to avoid more deaths because the illness is highly contagious.

A typical case appears similar to a common cold for up to two weeks, followed by coughing fits that sometimes end with a whooping sound.