Healthcare providers reported an increase in pediatric hospitalizations across the country for severe respiratory illnesses last month, which may be linked to an enterovirus strain that causes rare neurologic complications, the CDC announced in a Health Alert Network advisory on Friday.
In August, clinicians and health systems in several regions of the U.S. reported an increase in children hospitalized for severe respiratory illnesses who also tested positive for rhinovirus (RV) or enterovirus (EV), the advisory stated. Upon further testing, more of those cases tested positive for enterovirus D68 (EV-D68), a non-polio enterovirus linked to uncommon neurologic complications.
Between April and August 2022, the CDC noted a substantial increase in EV-D68 cases among children who were tested at facilities within the New Vaccine Surveillance Network (NVSN), which has seven sites across the country. The number of EV-D68 cases identified at all sites between July and August this year was greater than those detected in 2021, 2020 and 2019, the agency said.
In most cases, EV-D68 causes acute respiratory illness in children, with common symptoms in hospitalized patients including cough, shortness of breath, and wheezing. Fever has also been reported in approximately half of known cases.
EV-D68 also has been associated with acute flaccid myelitis (AFM), a rare neurologic disorder that can result in muscle pain and limb weakness.
As of Aug. 30, the CDC has not received any reports of AFM cases. "However, increases in EV-D68 respiratory illnesses have typically preceded cases of AFM, indicating that increased vigilance for AFM in the coming weeks will be essential," the agency stated.
The CDC recommended that healthcare providers consider EV-D68 as a possible cause of acute, severe respiratory illness in children, and make testing for EV or RV a typical part of their diagnostic routine.
The agency noted that rhinovirus and enterovirus have a very similar clinical presentation, and are almost indistinguishable from one another on the multiplex assays that are typically used in clinical settings. Distinguishing between rhinoviruses or enteroviruses, or identifying a specific type of either virus, requires typing using molecular sequencing or an EV-D68-specific real-time reverse transcription-polymerase chain reaction (rRT-PCR) test.
The agency also urged clinicians to "strongly consider AFM in patients with acute flaccid limb weakness, especially after respiratory illness or fever, and between the months of August and November 2022."
Additionally, as there are no available vaccines or antiviral therapies for any rhinovirus or enterovirus, the CDC recommended that clinicians provide supportive clinical management for RV or EV, including EV-D68.
Previous outbreaks of EV-D68 occurred in 2014, 2016, 2018, and to a lesser degree in 2020. These outbreaks were followed by increased AFM cases in the fall of 2014, 2016 and 2018, the CDC stated.
During the most recent outbreak of EV-D68 cases in 2018, the median age of children who sought inpatient or emergency department care for their illness was 3 years old, but children and adolescents of any age can be affected, the CDC said. While EV-D68 is not well understood in adults, it may be more commonly detected in patients with underlying conditions.