Cases of whooping cough in California are more than six times higher than last year, and in Los Angeles County, reports of the highly contagious disease are up nearly 220%, according to Department of Health data.
The spike reflects a broader trend seen across the country, with the number of U.S. cases reported in June this year more than doubling since last year, the Centers for Disease Control and Prevention reported. Public health officials say nationwide cases of the bacterial respiratory disease — which gets its name from the “whoop” sound made when gasping for air during a coughing fit — are returning to pre-pandemic levels.
“Reported cases of whooping cough have been lower than normal in recent years since the beginning of the COVID-19 pandemic,” the CDC’s National Center for Immunization and Respiratory Disease said in a July 22 statement. “It is likely that preventive measures during the pandemic (e.g. good hygiene, physical distancing) have reduced transmission of this disease.”
But public health data from earlier this year shows that cases in California have far exceeded cases nationally.
Rising cases in the state were reported Friday by the Los Angeles Times, with public health data over the summer revealing just how big the increase was. Some health experts have said that while cases are returning to the numbers seen years ago and are not reaching unprecedented new heights, there is still some concern about how contagious the disease is once it starts spreading.
“It’s a big year, no doubt, but I don’t think it’s dramatically bigger than the big years before the pandemic,” Mark Sawyer, a professor of pediatrics at UC San Diego, told the health and medicine journal Stat. Still, he added, “It’s a very, very contagious infection, so once the infection gets going, it spreads among susceptible people, and we may have built up a larger susceptible population than normal.”
Early symptoms, including a mild cough, runny nose and low-grade fever, are similar to those of a cold. But the bacterial disease can progress and become much worse with what the CDC describes as “rapid, violent and uncontrolled coughing fits,” in which patients have trouble breathing, vomit and even break a rib. Infants are especially at risk for dangerous complications.
Across California, there has been a 605.4% spike in cases since the start of the year through September 30, the latest data from the Department of Health shows. It is the highest number of whooping cough infections in the entire state since 2019.
There have been 1,744 cases reported in California during that time, compared to 288 in 2023.
More than a quarter of the state’s cases were in San Diego, where there were 470 compared to just 85 last year — marking a county-wide increase of about 553%. In LA County, they rose 219.9%, from 85 in 2023 to 186 this year.
For cases through early summer, the jump in cases in California was significantly larger than the national increase. Between January 1 and June 1, the number of cases in the US more than doubled from the previous year – an increase of about 284.7%. But in California, the number of cases was more than six times higher than last year for about the same period — a jump of 642.5%.
Still, this year’s number of infections is far from the highest the state has ever seen.
More than 9,000 cases were reported in 2010, the most in more than 60 years, during an outbreak that led to the deaths of ten babies. Four years later, the state reported more than 11,209 cases, with two infants dying from respiratory diseases.
Babies are at particularly high risk for dangerous complications from the disease. The CDC reports that more than a third of babies younger than 12 months who get whooping cough require treatment in a hospital.
