The United States experienced a 200% increase in brain abscesses in children in December 2022, following a surge in respiratory infections over the winter.
Despite this increase, brain abscesses remain extremely rare, according to the US Centers for Disease Control and Prevention (CDC).
Brain abscesses are pockets of pus that form in brain tissues, typically originating from sinus or ear infections that spread to the brain.
The CDC began collecting data on brain abscesses in children in May 2022 after doctors in Clark County, Nevada, and California reported unusual clusters of cases.
An initial analysis of the data through May 2022 showed that the fluctuations in case numbers were within normal ranges, but the CDC continued to monitor the situation.
In 2022, the number of brain abscesses in children in and around Las Vegas, Nevada, rose from the expected four or five to 17.
An update on Thursday analyzed cases through March 2023, adding 10 months of data. This update confirmed what pediatric infectious disease experts had observed across the US during the winter and spring: a rise in cases.
Using a large database managed by the Children’s Hospital Association, which collects information from 37 children’s hospitals in 19 states and Washington, D.C., CDC investigators reviewed medical records to count brain abscess cases in children ages 18 and younger since 2016.
The new investigation was published in the CDC’s Morbidity and Mortality Weekly Report on Thursday.
Investigators found that from 2016 to 2019, the average monthly number of brain abscesses in children reported to the database was about 34, with a peak of 61 cases in a month.
During the pandemic, when social distancing and virtual schooling were common—from May 2020 to May 2021—the number of brain abscesses in children fell below those levels as other respiratory infections like RSV and influenza also decreased.
The number of brain abscesses rebounded in the summer of 2021 as people resumed normal activities, according to the study.
In December 2022, following unusually large surges of several respiratory illnesses in children, the number of brain abscesses reached a high of 102 cases, representing a 200% increase over the pre-pandemic midpoint.
Although the numbers declined in January, February, and March 2023, they remained above the pre-pandemic monthly maximum.
“That would be consistent with seeing secondary bacterial infections a few weeks or months after the viral spread,” said Dr. Sunil Sood, a pediatric infectious disease expert at Northwell Health’s Cohen Children’s Medical Center.
The exact reason for the increase isn’t fully understood, but experts suggest that brain abscesses, which often follow more routine infections, are likely to rise after a heavy season of viral illnesses in children.
Dr. Sood noticed a similar increase in brain abscesses at his children’s hospital in New York, corresponding with national trends. He anticipates that cases will slow down as viral illnesses decline.
“We’re seeing fewer viral respiratory infections,” Sood said. “We’re still seeing some, and so it is something that is good to be aware of.”
He advised that most parents might not recognize the signs of a sinus infection requiring treatment.
These signs include an eye that’s swollen or swollen shut after a stuffy nose or a headache localized to one spot on the forehead. These symptoms may warrant a visit to the doctor for further evaluation.
Dr. Taryn Bragg, a pediatric neurosurgeon with the University of Utah who first raised the alarm about the Nevada cluster, noted that many of her patients are still recovering from their brain abscesses, with some requiring multiple surgeries.
“They were really severe infections,” Bragg said Thursday.
Study author Emma Accorsi of the CDC’s National Center for Immunization and Respiratory Diseases emphasized that because brain abscesses can follow viral infections, it’s important for children to stay up to date on immunizations, including for Covid-19 and the flu.
