Whooping cough epidemic hits county

Healdsburg at forefront of county pre-K vaccinations
As Sonoma County continues to lead incidence rates in the whooping cough (pertussis) epidemic sweeping through California, data has shown that Healdsburg is faring well in vaccination rates among children entering kindergarten, though health officials continue to urge caution.
In a report on pertussis issued on July 8, the California Department of Public Health (CDPH) identified Sonoma County as the county with the highest incidence rate for cases with an onset in 2014 (119.63 per 100,000 persons). According to the report, the 5,393 total cases reported to the CDPH with an onset in 2014 have resulted in a state rate of 14.1 cases per 100,000 person population.
“We are in the lead and we will continue to be until other people catch up,” said Dr. Karen Holbrook, who is the interim health officer for Sonoma County, noting that the number of cases arising within the county has lately regressed. “We’ve already peaked and have come down and our decline has been stable for six weeks now,” she said. According to Holbrook, the peak occurred in April and May.
Holbrook said other jurisdictions are seeing an increase in pertussis cases, though Sonoma County will continue to lead incidence rates until other counties “catch up.” Despite the recent regression, Holbrook said residents should not become complacent: “We are still having pertussis cases in the county and I don’t want people to let down their guard,” she said.
Whooping cough typically adheres to a three to five year cycle, gaining strength due to waning immunity over time. “Back before there was even a vaccine people would have a peak year and it would kind of come through a community,” Holbrook said. “…It was a combination of new people coming into the community and also waning immunity, and so that also happens now in the vaccine era, although the number of cases is dramatically less.”
In addition, Holbrook said that the medical community has recently grown aware of the downsides of an acellular pertussis vaccine that has been in use since the mid-’90s. “The immunity seems to wane a little faster than the whole-cell vaccine,” she said.
Holbrook posits that rapid intercommunication may have helped Sonoma County reduce the number of cases lately identified. With the Department of Health Services issuing communications to the schools, who in turn shared information within their communities, parents took the initiative to seek medical attention for their children and encourage clinicians to consider a pertussis diagnosis. “It took a little effort on the clinicians’ part to learn that some of these cases were pertussis,” Holbrook said.
According to Alexander Valley Healthcare (AVH) in Cloverdale, pertussis starts with symptoms reminiscent of the flu, including a runny nose. Later, coughing fits set in for a few of weeks, and takes another four to five weeks to subside. Within Sonoma County, Holbrook said the majority of patients diagnosed with pertussis were between 10 and 14 years old, while the second largest population was between 15 and 19 years old. The more mild symptoms common among older children may render the disease more difficult to diagnose for that age group, she said.
While pertussis diagnoses occurred most prevalently among school-aged children in Sonoma County, infants are especially vulnerable to the disease, according to AVH. Pregnant women may receive the vaccination in the third trimester of each pregnancy to transmit anti-bodies to their infant. During an epidemic period, Holbrook said that infants may receive a vaccine as early as when they are six weeks old. Shots in the DTaP vaccine series are also administered at two months, four months, six months, 15 months and when the children are 5 years old.
A booster shot is recommended for seventh graders, as well as an additional dose in adulthood. In a press release, AVH CEO Deborah Howell said that “anyone coming in contact with infants and children should be vaccinated,” creating a “cocooning effect” around vulnerable children.
According to data on vaccination rates in selected Sonoma County kindergartens issued by AVH, Healdsburg retains a relatively high vaccination rate for children entering kindergarten. The data, gathered on a rolling average from 2010 to 2012, showed a 98.7 percent vaccination rate.
In March, the Healdsburg Unified School District issued a notice to parents informing them that the district is continuing to see increased rates of pertussis at schools. They recommended that students and staff with a cough inform their physician of the possible exposure to pertussis and be examined, regardless of immunization status. The notice stated that individuals diagnosed with pertussis would be excluded from school or child care until five days of an antibiotic were issued.