Flathead City-County Health Department officials reported new pertussis (whooping cough) cases Monday with one at Glacier High School and another at Bigfork High School.

“We’re at 31 cases,” said Jody White, director of Community Health Services.

Except for the two high school cases, the rest of the new positive tests were in adults.

White said Monday that the Bigfork student had not been previously reported as a contact of other ill people. The Glacier  student had contact with a sick child under 5.

Once someone in a household becomes infected with pertussis, White said, it spreads very rapidly if the other people in the household haven’t been immunized or take recommended antibiotics to prevent further transmission.

White said nurses at the high schools prepared lists of people who had contact with the infected students. Health department employees began calling those students’ families on Tuesday.

Health officials tell families that students who haven’t been immunized earlier need to take a preventive five-day course of antibiotics (prophylaxis) or stay out of school for 21 days, the incubation period for the disease. If a person has been exposed, the antibiotics stop the spread of the disease but may not decrease the severity or length of the illness.

White said that the health department has tried to be diligent in its contact investigation without over-medicating.

 “We don’t want to prophylax entire high school classes,” White said. “We’re really trying to only prophylax those at risk of having contact.”

White said some health-care providers have become concerned that pertussis continues to crop up.

“It’s concerning,” White said. “It’s hard to know if there’s an underlying level of disease that’s not being diagnosed.”

Even some people who received immunizations have developed pertussis, however health officials say vaccination remains the most effective way to control the disease in a population. Montana law specifies that schools require children to show proof of pertussis and other vaccinations before enrolling.

The Centers for Disease Control and Prevention website describes pertussis as starting with cold-like symptoms and a mild cough or fever that progresses to a violent, rapid, uncontrolled cough within one to two weeks. Infants may not have a cough but pauses in breathing instead.  

Health officials advise adults to request that medical providers perform pertussis tests if they observe suspect symptoms in their children or themselves. For the lab test, providers collect a specimen of secretions with a swab or syringe from the back of the throat through the nose.

Reporter Candace Chase may be reached at 758-4436 or by email at cchase@dailyinterlake.com.