So far this year, the St. Louis County Health Department has logged more than 200 cases of whooping cough, a bacterial infection that affects the respiratory tract.
During a meeting of the St. Louis County Health Advisory Board earlier this week, county Senior Epidemiologist Amanda Brzozowski said 90% of the reported cases of whooping cough, also called pertussis, have been reported by one pediatric clinic in west St. Louis County.
However, that doesn’t mean that kids there are more sick than in other parts of the county, Brzozowski said. Instead, the facility, Baer Pediatrics in Town and Country, has a new policy of ordering tests for all patients who have persistent coughing and other whooping cough symptoms.
It’s likely that the actual prevalence of whooping cough in the region is higher than reported, she said.
“I think we’re seeing the tip of the tip of the iceberg here, because my suspicion is that every other area in the county is also seeing similar infection rates,” Brzozowski said. “If the other practices in the area or all of the practices in the county were following the same testing protocols, I think we would be getting dozens of cases a day.”
Whooping cough is caused by a bacterial infection and gets its name from the sound patients make when they gasp for air after a severe coughing fit. It’s very contagious and particularly dangerous in infants.
Because whooping cough symptoms mimic those of other infections, it's not always identified without testing and sometimes mistaken for other, less contagious illnesses.
Pediatrician Kristen Mennemeier, who owns Baer Pediatrics, said her practice started ordering the tests when doctors began to see more cases of whooping cough and pneumonia this fall.
Patients were coughing for weeks, sometimes to the point of vomiting, she said.
Mennemeier was surprised more clinics aren’t doing more testing as cases of whooping cough rise in Missouri and across the country. So far this year, the state has tallied 540 cases, compared with 58 cases reported at this point in 2023.
“This morning, I think, in our practice, we've already had 15 positive results, and it's only 10 o'clock,” she said. “We are seeing a large number of pertussis cases, that's for sure.”
Both Mennemeier and county health officials said pertussis tests can be expensive – some cost more than $100. That could be why more doctors aren’t ordering them. A positive whooping cough test also means doctors recommend staying home from school or work for five days, a sacrifice some patients may not be able to afford.
She said she hopes more practitioners and school nurses learn about the outbreak so they can be on the lookout for symptoms.
Health officials say the best way to protect against whooping cough is by getting the tetanus, diphtheria and pertussis vaccine. It’s usually given to children, adolescents and pregnant women.
Doctors have emphasized that it’s particularly important for pregnant women to get the shot to transfer immunity to their fetus. Infants younger than two months are too young for the immunization.
State and local health officials say pertussis infection rates are cyclical — they’ll recede for a few years and then rise again. The coronavirus pandemic disrupted this cycle, but case counts are now hitting pre-pandemic levels.
The rise in cases also could be attributable to a change in the vaccine, Mennemeier said. Previous versions of the pertussis vaccine caused a lot of side effects. The new version has fewer side effects but appears to lose efficacy over time.
“I think it's a combination of, certainly, there's less people that are vaccinating which can contribute to it,” she said. “Potentially, our booster doses [for] pertussis are wearing off sooner than we would like them to.”
Mennemeier added that although there were many cases recorded among her patients, they have been vaccinated and have avoided serious complications.
