A Rise in Brain Abscesses Among Children in Clark County, Nevada, 2022

What happened

In October 2022, the Southern Nevada Health District heard that more children than expected were being hospitalized with intracranial abscesses — pockets of infection inside the skull — a concern already raised nationally. The infection is rare but causes serious illness. By then, 14 cases had been diagnosed at southern Nevada's largest children's hospital. The district set out to confirm the cluster, look for common risk factors, inform the community and recommend prevention.

How cases were counted

• Past years: hospital discharge records from all hospitals in Clark County, 2015–2021, for patients 18 or younger with a diagnosis of intracranial abscess and granuloma or extradural or subdural abscess.
• 2022: mostly reports from providers, confirmed with discharge data where available. A case was an abscess or empyema within the brain, under or over its covering membranes, or other infection spreading inside the skull on brain imaging, in a child with no previous brain surgery or significant head injury.
• Medical records were reviewed, and families were interviewed by phone about the illness, risk factors and exposures.

What was found

Pediatric intracranial infections by quarter, with the median, 2015–2022. Figure from the CDC report.

The 18 children of 2022:

• median age 12 (range 4–15); all but four were boys;
• hospitalized a median of 15 days (9–76); 15 needed a craniotomy to drain the abscess;
• 14 had sinusitis, and four mastoiditis (infection of the bone behind the ear);
• none tested positive for SARS-CoV-2 on admission, and none died.

Family interviews (14 caregivers):

• nine said the child had cold symptoms such as a runny nose beforehand; seven had other symptoms — headache (three), headache with fever (three), or minor head injuries (two);
• eleven had sought care before the hospitalization, most often at an emergency department (seven);
• the median time from first symptoms to hospitalization was 7 days (2–14);
• nine children had been swimming in the 4 weeks before, but not at the same pools;
• five families said they had stopped masking after Nevada's mask mandate ended — three of them children who then had cold symptoms. (The mandate required masks in indoor public places, including schools, from July 19, 2021, to February 10, 2022.)

What it means

A 2022 national investigation also found more pediatric intracranial abscesses in 2022 than in 2021, beginning with a rise in mid-2021 after a stretch of consistently low counts early in the pandemic — the same pattern seen here. This investigation found no unexpected risk factors, but the sharp increase after the mask mandate was lifted may partly reflect changes in how respiratory infections spread.

The health district sent a health advisory to pediatric providers and planned to keep tracking cases through 2023.

Sources

Based on Jessica A. Penney, Ying Zhang, Taryn Bragg and others, "Notes from the Field: Pediatric Intracranial Infections — Clark County, Nevada, January–December 2022," MMWR, Centers for Disease Control and Prevention; a work of the United States government in the public domain.