As of Thursday, September 5, there are 169 confirmed cases of pertussis, also known as whooping cough in Missoula County.

Missoula City County Health Department Director Ellen Leahy confirmed to KGVO News that since school has started there are two new cases reported in Missoula’s public elementary schools.

“169 cases from the beginning of the outbreak in April, about 20 of those through the summer, and now we have two cases, one confirmed by the lab and one that is linked to that particular case in school children,” said Leahy. “We are working with those families in those particular schools and, as is often the case, day care can be involved. Some of the kids have younger children at home that go to day care or they might go to day care after school.”

Leahy provided a scenario of how the health department attempts to both treat and prevent the spread of pertussis.

“Let’s say for example that a child is in second grade and mom maybe has an infant at home,” she said. “We not only want the child in the second grade to not spread it to classmates. The child in second grade might also have after school daycare for a couple of hours, so we want to make sure it doesn’t spread there. Then, Mom at home with the infant, that infant is probably not fully immunized yet because they’re too young, so we’re really concerned about it not spreading to that infant because it’s a high risk disease for infants and for pregnant women. Our two goals are to stop the spread from each case, but also to identify someone who may have a high risk of complications from pertussis.”

Leahy said the pertussis vaccine is not as continuously effective as others, such as the measles vaccine.

“While immunization does offer some protection, the immunization on this particular disease is not holding with a high level of strength,” she said. “It’s very difficult to say you’re almost 100 percent safe like you would with measles, but this particular vaccine isn’t holding like that. In other words, being immunized is not a guarantee that you’re not going to get the disease.”

To further complicate the picture, Leahy said those who have been immunized can still contract pertussis, but the symptoms may not be as strong.

“They sometimes present with a lesser case, and that may make it less likely that the child, the mom or dad seeks healthcare attention, yet that person is still contagious,” she said. That makes the situation more difficult for the family, the school and the healthcare provider to figure out the cause of the symptoms.”

Leahy said the surest way to determine pertussis is to be tested specifically for the disease either by the healthcare provider or by the Missoula City County Health Department.

Leahy said proving that pertussis is present is proving more difficult in this particular outbreak, however, she urges anyone who may have not been immunized to do so.

“Certainly, if you have not received the immunization or the booster, we offer them here, your physician can also provide the vaccine,” she said. “We have a sliding fee scale at the health department, but if there are no more resources for the family, we’ll make sure that a child gets those immunizations without worrying about the cost.”