Whooping Cough Is Back With a Vengeance

Last year, there were just under 4,000 cases of whooping cough in the US. So far in 2024, there are upward of 17,500—a spike of more than 340%, per Fortune. That's according to the latest CDC stats, released for the week ending Oct. 5, in what NPR calls the "worst US whooping cough outbreak in a decade." And experts say the reported numbers are likely on the low side, as cases with minor symptoms often go undiagnosed. More:

• Contagious disease: Whooping cough, also known as pertussis, is a very contagious respiratory illness caused by the Bordetella pertussis bacteria that's typically accompanied by an uncontrollable hacking cough, "followed by a high-pitched intake of breath that sounds like 'whoop,'" as described by the Mayo Clinic. Initial symptoms mirror those of allergies or the common cold—congestion, runny nose, watery eyes—with more serious symptoms including severe fatigue and vomiting from all the coughing.

• Who it affects: The illness most often crops up in infants and young kids who haven't undergone their full round of vaccinations yet, specifically the diphtheria, tetanus, and pertussis (DTaP) vaccine. However, because the more modern version of the vaccine wanes over time, older kids, teens, and adults should get a new shot every 10 years to maximize protection. Whooping cough is especially dangerous for babies, even sometimes fatal, with 1 in 3 infants hospitalized for the illness.
• Numbers shift: Fortune notes that, before COVID, there were typically more than 10,000 whooping cough cases per year, with nearly 19,000 logged as recently as 2019. Once the pandemic hit, however, cases didn't number over 6,100 annually; in 2021, there was a record low of just 2,100 cases, with outbreaks partly kept away by the masks, social distancing, and remote work of peak COVID. Now, "the United States is beginning to return to prepandemic patterns," a CDC rep says, per Scientific American.
• States' status: Ohio had the highest number of cases for the week ending Oct. 5 (44), followed by New York (34), Pennsylvania (28), Alaska (25), and Virginia (20).
• So why the uptick? NPR notes that experts cite several possibilities, including more testing, a potentially mutated bacteria, and a lack of vaccinations during COVID—both from those who couldn't get to their doctors and those who wouldn't get themselves or their kids vaccinated. "There still is a lot of vaccine hesitancy and anti-vaxxers out there that will not vaccinate their kids," says Dr. Tina Tan, a pediatric physician at Northwestern University.

(More whooping cough stories.)