SAN DIEGO -- A 2-month-old baby in a daycare program at an Oceanside high school was diagnosed with whooping cough, the San Diego County Health and Human Services Agency announced Wednesday.

County health officials were working with the staff at the daycare at Ocean Shores High School to notify the parents of children who may have come into contact with the sick infant, HHSA officials said.

So far this year, there have been 96 cases of whooping cough in San Diego County, compared to 51 cases last year.

Whooping cough can occur at any age, but infants and young children have the highest risk of developing life-threatening complications, the most common of which is pneumonia.

Whooping cough, also called pertussis, usually starts with flu-like symptoms such as runny nose, sneezing, fever and a mild cough.

The symptoms may be mild and brief, and last up to two weeks, but are often followed by severe coughing fits that may be associated with vomiting. Whooping cough is treated with antibiotics.