Pertussis, commonly known as whooping cough, continues to surge in southwest Idaho. In the ten-county area managed by Central and Southwest District Health offices, there have been 222 confirmed cases as of Oct. 7 this year, 51 new since Sept. 5.
Most of this year’s cases in the two health districts are in Ada and Canyon counties.
“Pertussis is a bacteria that’s cyclical locally and nationally,” said Central District Health Epidemiology Program Manager Sarah Wright. “We know to expect it every 3 to 5 years; this outbreak is not an exception to that.”
Infection rates in the Central District Health area are about the same as they were during the last outbreak in 2019, Wright said. Southwest District Health office spokeswoman Monique Evancic wrote by email that infection rates in that area are slightly less than 2019. Area population increases mean the total number of cases is higher.
Known for its violent and long-lasting cough, pertussis in southwest Idaho this year is not consistently presenting with the trademark "whoop" sound infected people can make as they inhale while coughing.
Wright called that aspect of the outbreak "unique," and said it likely means fewer people getting tested for pertussis as other illnesses like COVID-19 and the flu circulate.
“It's not super common for people to go in and get tested for something like pertussis, unless they've had a cough for a really long time,” she said. ”We know that cases are being underreported just due to [a lack of] testing.”
Because schools are also a common transmission point, health officials often work with school nurses. Pertussis has popped up in most major high schools, junior high and elementary schools in the Central Health District. Sometimes nurses reach out for advice, sometimes health officials notice multiple cases tied to the same school and make contact.
“We can make recommendations like sending out a letter or an email to teachers,” Wright said. “It is ultimately up to the school and the administrators whether or not they want to send out that communication.”
Not every school chooses to announce a positive case to its community, but Wright said CDH doesn’t track that notification data.
“We’ve got to improve our public health communication,” said Dr. David Pate, former St. Luke’s Health System CEO. Pate speaks weekly with Boise State Public Radio on health-related issues on Idaho Matters.
“Any time there’s an outbreak of a communicable disease, affecting the public and especially our children, I do think we should know and be put on alert,” Pate said.
The health department will, when it has the capacity, Wright said, attempt to reach people who tested positive to try and get a list of close contacts to be notified.
If you have been exposed to pertussis, antibiotic treatment is effective at limiting its spread. Wright urges anyone experiencing symptoms to consider getting tested. “It's important if you think that you may have been exposed and you're at higher risk of severe disease, you are a baby under 12 months old or [are] in the third trimester of pregnancy, or have certain health conditions, to reach out to your provider and make sure you're getting the testing and treatment.”
Vaccination against pertussis is also available, and can reduce the threat of severe disease. It is commonly given to children as part of the Tdap shot series, but vaccination rates among Idaho kindergarteners has been falling. the Centers for Disease Control and Prevention recommends booster shots every 7-10 years for adults to maintain effective protection against pertussis.
