5,600+ cases of whooping cough in Calif.

LOS ANGELES According to health officials, of the cases with hospitalization information, 10 percent required admission.

Three-quarters of hospitalizations occurred in infants younger than six months, and of those, nine died.

Officials first noticed an increase in whooping cough in April, but the epidemic wasn't declared until June.

Whooping cough or pertussis typically starts with a cough and runny nose for up to two weeks. It is followed by weeks to months of rapid coughing fits.

The illness is treatable with antibiotics.

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