Whooping cough cases are nearing their pre-pandemic rates, according to the U.S. Centers for Disease Control and Prevention (CDC).
The CDC attributes the uptick to less protective measures (masks, social distancing) and lower vaccination rates. They anticipate incidence rates to rise in both vaccinated and unvaccinated people. CDC data show “more than six times as many cases have been reported as of week 52 reported on December 28, 2024, compared to the same time in 2023.” According to an article by Devna Bose in The Associated Press, 2025 has already seen “twice as many cases as this time last year, based on the CDC’s final tally.” Bose cites CDC preliminary data, reporting 8,485 cases this year so far.
The CDC says vaccination is still the best way to prevent the disease. Bose pointed out “U.S. kindergarten vaccination rates fell last year, and the number of children with vaccine exemptions hit an all-time high.”
What labs should know
The CDC still recommends polymerase chain reaction (PCR) testing as the best way to diagnose whooping cough. Although, “only patients with signs and symptoms consistent with pertussis should be tested by PCR to confirm the diagnosis.” Testing patients who are not currently experiencing symptoms could lead to a false diagnosis. Additionally, “asymptomatic close contacts of confirmed cases shouldn't be tested and testing of contacts shouldn't be used for postexposure prophylaxis decisions.”
PCR should be performed within the “first 3 weeks of cough when bacterial DNA is still present in the nasopharynx.” The CDC advises against PCR testing after 5 days of antibiotics. DNA should be collected “by aspiration or swabbing the posterior nasopharynx.” The CDC lists additional best practices for specimen handling and interpreting results.
