Marin, Humboldt, Sonoma and Fresno counties have some of the highest rates of pertussis. Whooping cough surges every three to five years, but Dr. Dean Blumberg of the UC Davis Health System says this year is terrible.
“We had a big outbreak in 2010 so it wasn’t completely unexpected to have another uptick in cases this year but it’s higher than anybody expected," says Blumberg.
Blumberg says the biggest contributing factor in counties with high rates may be the number of parents who choose not to vaccinate their children because of personal beliefs. He says Latinos are disproportionately affected by the disease. The ten infants who died in 2010 were Latino.
But the California Department of Public Health it’s not sure how to explain the whooping cough clusters.
“It’s just hard to know, we really don’t know," says Blumberg.
Kathleen Harriman of the department says good insurance and access to medical care can factor into the higher rates of diagnosis.
“We do think testing and awareness has a lot to do with it, certainly, the number of susceptible people makes a difference, and just kind of where pertussis gets into the population first," says Harriman.
The spread of whooping cough is still significant. Both experts say it’s too soon to tell when the surge will taper off.
Whooping Cough Rates Per 100,000 people: