At the beginning of each recent school year, Mill Valley School District Nurse Martha Parker scrambles to handle an ever-increasing enrollment. This year has brought an additional challenge, but one that she saw coming.
Pertussis, a highly contagious bacterial disease that is also known as whooping cough, hit epidemic proportions in Mill Valley and beyond at the end of the past school year, with one local elementary school having 20 students getting treatment for it. And while the number of cases dipped over the summer countywide, Parker is readying herself for another onslaught.
"I think it's going to be a bigger issue this year," Parker said last week. "It's already started off strong with two cases right now (at Mill Valley Middle School), so I'm very concerned. I don't think we've seen the total effect of getting these kids all back together again in the same rooms."
At least 286 Marin residents have contracted the disease this year, as of Aug. 31, according to the Marin County's public health division. But the monthly totals have declined dramatically since June, when the county peaked at about 34 cases per week, according to Dr. Anju Goel, the county's deputy public health officer.
Parker and county officials continue to spread the message about the importance of vaccinations. Informational campaigns about the pertussis vaccine have helped, she said, and there has been marked improvement in the community's knowledge about pertussis since the peak period of May and June.
"But there is still confusion," she said. "I had a parent today who said she didn't realize that pertussis and whooping cough were the same illness."
A typical case of whooping cough often appears similar to a common cold, starting with a cough and runny nose for one to two weeks and followed by weeks or months of rapid coughing fits that sometimes end with a whooping sound.
In addition to education, a major hurdle for local health officials is the stigma of vaccines, particularly in Marin County. The TDAP vaccine against whooping cough is free of the additive thimerosal, a preservative containing mercury that has been the subject of a long-running public debate about whether it can cause autism. A federal ruling in March said there was no connection between autism and thimerosal.
But while state law requires kindergartners to be vaccinated against whooping cough before they can attend school, parents who object to the vaccination because of autism fears or religious grounds have cited "personal belief exemptions" for their refusal to allow their children to be vaccinated.
Parker estimates that up to 18 percent of district students are either not immunized or are partially immunized, while between 5 and 8 percent are not immunized at all.
In 2009, the parents of about 2 percent of kindergartners in California, or 10,280 students in all, signed personal belief exemptions, meaning they had refused some or all immunizations based on religious or personal beliefs.
Such stances negatively impact the "herd immunity," Goel said, meaning that community's efforts to fight the disease are stronger if more people are immunized.
Another issue is that while many vaccinations last for many years, pertussis vaccinations often require a booster shot after just a few years. County heath officials recommend that teenagers and young adults get a booster shot.
The county is now recommending a booster shot for anyone 7 years of age or older who may not be fully immunized. Goel said that the number of vaccinations delivered countywide has risen in recent weeks, particularly with the arrival of the school year.
"I do feel like we're getting the word out," Goel said.