Another major outbreak of whooping cough, a highly contagious respiratory disease, has hit hard in Marin County this year, public health officials said.
Marin County’s Department of Health and Human Services reported 229 cases this year of pertussis, commonly known as whooping cough — the largest outbreak in the county since 2014. Statewide, 2,942 cases were reported since Jan. 1. Outbreaks commonly occur every three to five years, the department said.
The illness is characterized by prolonged coughing fits and other cold-like symptoms, including fevers, runny noses and sneezing. People who are infected can sometimes cough so hard they lose oxygen and pass out. In extreme cases, infants have died from pertussis.
The Reed Union School District in Tiburon reported an outbreak in all three of its schools this month that sickened eight students, according to Superintendent Nancy Lynch.
The district sent out notices to parents when the illness was first reported and again when it began to spread. The message warned parents to look out for the signs of pertussis and check up on students’ immunization records.
“It’s always a concern any time students are sick and are out of school,” Lynch said.
This year’s outbreak hit hardest in local high schools. Students at Sir Francis Drake High School in San Anselmo reported the highest number of infections with 56 cases this spring, the health department said.
“The good news is that high school students generally bounce back from a bout of pertussis, especially if they’ve been vaccinated,” said Dr. Matt Willis, Marin County’s public health officer.
“The real concern,” he said, “is to make sure they’re not bringing it home to more vulnerable family members, especially if there are any infants in the house.”
Nearly all of the pertussis-related deaths in California over the past decade have been in infants under 1 year old, according to Willis.
The disease is treated with antibiotics, and Willis recommends family members who are exposed to the bacteria receive treatment.
Whooping cough is largely preventable by vaccine, according to the health department. People who are vaccinated can still contract whooping cough, but they often report less severe symptoms that last for a shorter duration, the department said.
The vaccine is generally administered in a combination injection called DTaP, which helps prevent diphtheria, tetanus and pertussis. The vaccinations, which last three to five years, are required by state law for students entering kindergarten and seventh grade.
With rising vaccination rates in Marin County, Willis hopes the illness will become less prevalent in the future. In the county this year, about 96 percent of kindergartners and 98 percent of seventh-graders were up to date on DTaP vaccinations, according to the health department.
“We’ve traditionally had very low vaccination rates compared to other counties,” he said. “During that history of lower vaccination rates, the bacteria that causes pertussis was really able to establish itself in our environment and is still being circulated throughout the county.”
A major statewide outbreak of pertussis in 2010 was the worst the state had seen in over 60 years. Of the 9,000 cases reported throughout California, Marin had 351 — the most of any county in the state. That outbreak included 10 infant deaths, none of which occurred in Marin County.
Three California counties had outbreaks worse than Marin’s this year. The worst hit San Diego, where 593 cases were reported. There were 300 cases in Alameda and 295 in Los Angeles.
At Marin Community Clinics, staff members administer DTaP vaccinations on a daily basis, said Dr. Peter Simon, a physician with the clinic.
“It’s really important for healthy people to get the vaccine when it’s recommended, because that’s how we protect babies, who are at a high risk,” he said.
Because pertussis is common in California, doctors at the clinic routinely check for the illness in patients who report bad coughing fits.
“It’s always in the back of our minds,” Simon said.
