California’s and the nation’s current pertussis (whooping cough) epidemic has not abated as spring turned to summer.

“California is currently experiencing a pertussis epidemic … The last epidemic in California occurred in 2010, however, the overall incidence of pertussis has increased since the 1990s … Young infants are at greatest risk of hospitalization and death from pertussis, therefore pregnant women are encouraged to receive pertussis vaccine (Tdap) during the 3rd trimester of every pregnancy,” the California Department of Public Health wrote in its July 8 report.

Another 835 cases were confirmed in the two weeks from June 24 to July 8. The total confirmed cases in 2014 is at nearly 5,400, which is already twice the number of cases in all of 2013.

Riverside County reported 180 cases of pertussis, compared to 126 cases combined in 2012 and 2013 and 166 in 2011.

The majority of cases where the victim’s age is known have occurred in infants and children less than 18 years of age and 278 (or 7 percent) were infants under 6 months of age. A total of 156 people have been hospitalized and 29 of these required intensive care. Of the hospitalized patients, 97 were infants less than 4 months of age.

The symptoms of pertussis vary by age. For children, pertussis typically starts with a cough and runny nose that can last up to two weeks. The cough then worsens and turns into rapid coughing spells that end with a tell-tale “whooping” sound.

Young infants may not have typical pertussis symptoms and may have no apparent cough. Parents describe episodes in which the infant’s face turns red or purple.

For adults, pertussis may simply be a cough that lasts for several weeks. Older children, pre-adolescents and adults should also be vaccinated against pertussis according to current recommendations.