Last winter saw a "large spike" in very rare pediatric brain infections, CDC reports
Hospitals reported a "large spike" of children with brain infections this past winter to the highest levels seen in several years, the Centers for Disease Control and Prevention said Thursday, but cases still remain rare overall.
The new findings were published in the CDC's Morbidity and Mortality Weekly Report, updating a previous analysis from the same database run by the Children's Hospital Association.
The CDC first began probing a potential increase in "pediatric intracranial infections" earlier last year, after doctors reported an uptick of these very rare hospitalizations, with many children infected by the bacteria Streptococcus.
Cases had initially fallen steeply after the COVID-19 pandemic began. They climbed again to a peak in March 2022, marking what appeared to be a return to levels "consistent with historical seasonal fluctuations" before the pandemic.
But health authorities in Nevada were among those to raise the alarm over another surge of the very rare brain infections this past winter that appeared to be climbing to levels beyond previous peaks seen before the pandemic.
Investigators suspected the increase could be linked to a resurgence in the wake of Nevada lifting its COVID-19 masking requirements.
The seasonal patterns of respiratory infections like influenza and RSV had also been disrupted during the first years of the COVID-19 pandemic, before returning to larger peaks this past winter.
The CDC's latest analysis finds that the monthly pace of patients diagnosed with these brain infections never returned to its "prepandemic baseline" after climbing last year.
"During January-March 2023, case counts began to decline but remained above the baseline maximum. Although some variability between U.S. Census Bureau regions was observed, overall patterns were generally similar," the report's authors wrote.
Across the 37 pediatric hospitals in the database going back to 2016, a median of 34 cases had been reported each month before the pandemic.
At its previous peak, 61 cases were tallied over the winter of 2016 to 2017. This past winter, cases peaked at 102 in December.
Pediatric intracranial infections investigated by the CDC – which include pus pooling in abscesses or empyemas around the brain – are a very rare but serious complication that has been seen from Streptococcus bacteria.
The vast majority of infections from Streptococcus only result in symptoms like strep throat, alongside other germs that spread largely from the nose and throat.
But in rare cases, invasive diseases can progress from headaches to more worrying signs like seizures and changes in mental status.
"In terms of symptoms, they can initially be very subtle for those presenting, which is sometimes why there is a little bit of a delay in diagnosis," the CDC's Jessica Penney said at an agency meeting in April, discussing early results from their probe.