Whooping cough cases rise sharply
Pertussis (whooping cough) cases by year
*Number of cases reported to the CDPH as of Dec. 18, 2013. Data for 2013 are still preliminary and will not be finalized until spring 2014.
Source: California Department of Public Health
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Whooping cough is a disease that is preventable through vaccination, though California is one of 20 states that allow parents to exempt their children from public school immunization requirements if they have personal objections.
SACRAMENTO – California has experienced a sharp increase in the number of cases of whooping cough, a highly contagious respiratory disease once believed to be nearly eradicated.
According to a California Department of Public Health report, the number of reported cases of whooping cough, also known as pertussis, increased to 1,904 last year from 1,023 in 2012. About 82 percent of the cases were in infants and children younger than 18. No deaths were reported in either year.
In Orange County, the number of reported cases rose to 93 last year from 74 in 2012, according to the state. Riverside County had a larger increase, 70 last year, up from 46 in 2012. In Long Beach, the number of cases rose to 12 last year from four in 2012.
Matt Zahn, medical director of epidemiology at Orange County Public Health, said the uptick of whooping cough cases in the county is not enough of a change to say whether a trend is developing.
“Year to year, the numbers will bounce around a bit,” Zahn said. “If those changes herald a new wave, I don't think we can conclude that right now.”
Zahn said residents should not be overly concerned. He emphasized that the number of cases recorded in 2013 – 93 – have yet to compare to the larger outbreak numbers the county saw in 2010 – 499 cases.
State health officials say one possible reason for the increase is declining immunity among children who were vaccinated years earlier but haven't received the booster shot recommended at ages 11 or 12. Other factors include the disease's cyclical nature and more parents opting out of immunizations for their children.
Caused by a bacterium, whooping cough causes violent coughing that makes it difficult to catch one's breath. Coughing spells can last for 10 weeks. It typically affects babies and young children and can be fatal for infants younger than 1 year old.
“Babies who are really young do not have the protection they need against the disease,” said Olivia Kasirye, Sacramento County's public health officer. “They depend on the community for the protection.”
The Centers for Disease Control and Prevention last year received reports of 48,000 cases of pertussis nationwide, more than in any other year after immunizations became widely available.
Nevada County had the sharpest increase in cases per 100,000 residents, jumping to 70 cases last year from five in 2012.
“Evidence shows that pertussis outbreaks are more likely in communities with clusters of unvaccinated people,” said Dr. Ken Cutler, Nevada County's health officer. “It is also clear that people who are unvaccinated are more likely than those who are vaccinated to get pertussis and to have more severe symptoms.”
Data for 2013 are still preliminary and will not be finalized until spring.
Register staff writer Kendra Ablaza contributed to this report.