The California Department of Public Health has reported more than 2,600 cases of pertussis, or whooping cough, since the beginning of the year. That’s more than the number of cases reported in all of 2013.
Whooping cough peaks every three to five years, and the last major outbreak was in 2010. That makes Dr. Kathleen Harriman believe this could be another big year for the disease.
"This could be a peak year for pertussis in California," said Harriman, chief of the vaccine-preventable disease epidemiology section at the state health department. She added that it "would be the right time for us to have another peak year."
Whooping cough is a highly contagious disease that’s usually spread through coughing or sneezing, while in close contact with others, according to the Centers for Disease Control and Prevention.
It peaks cyclically as more people become susceptible, either because their vaccine wanes, they’re unvaccinated, or because they’re too young to be vaccinated, Harriman said. Unlike measles - another disease that peaked this year - the pertussis vaccine does not confer lifelong immunity.
"As the number of susceptible people increases enough, there's enough of them to really sustain transmission," she explained.
This year, 83 percent of cases have occurred in infants and kids younger than 18 years old. Disease outbreaks have occurred in elementary, middle and high schools in counties across California, according to the state health department.
But infants who are too young to be vaccinated are at the greatest risk of hospitalization and death from whooping cough. Two babies have died of whooping cough this year, including one infant from Riverside County.
“Our main goal at CDPH is the prevention of infant deaths due to pertussis,” Harriman said. “We really just don’t want infants to die of a vaccine-preventable disease.”
For that reason, she urges all pregnant women to get vaccinated against whooping cough during the third trimester of each pregnancy. That’s intended to help protect infants against the disease, until they can get their first dose of the vaccine at 6 months of age. Kids need five doses of the pertussis vaccine by kindergarten.
A typical case of whooping cough starts with a cough and runny nose for one to two weeks, according to the state health department. As the cough worsens, kids may have rapid coughing spells that end with a whooping sound.