CDC Warns of Enterovirus Strain Linked to AFM CDC Warns of Enterovirus Strain Linked to AFM

A recent uptick in severe respiratory illness in children may be tied to a strain of enterovirus that can cause a rare polio-like condition, according to a Health Network Alert advisory on September 9, by the Centers for Disease Control and Prevention (CDC).

In August, healthcare providers and hospitals notified the CDC of an increase in severe respiratory illness in children who also tested positive for rhinovirus (RV) or enterovirus (EV). Additional testing revealed that some children were positive for EV-D68. EV-D68 primarily causes acute respiratory illness. However, the virus has been associated with acute flaccid myelitis (AFM), a rare neurologic condition involving muscle weakness.

Also, in July and August 2022, surveillance networks reported an increase in EV-D68 activity compared with the same months in 2019, 2020, and 2021, the agency said in the alert. As of August 30, the CDC has not received any reports of AFM beginning this year; however, spikes in EV-D68 typically come before cases of AFM, they said.

“Something we are always on the lookout for in the late summer and fall is AFM cases,” said Rick Malley, MD, of the division of infectious disease at Boston Children’s Hospital, in an interview with Medscape Medical News. “Unfortunately, we kind of expect them during enterovirus season,” he said. That season is thought to peak in the late summer and early fall.

Since the CDC began tracking AFM in August 2014, there have been 692 confirmed cases in the United States. AFM cases spiked in 2014, 2016, and 2018, mostly in young children. In 2021, there were 28 confirmed cases across 15 states. The CDC did not specify the age of those cases, but in 2018 — when EV-D68 most recently circulated at high levels — the median age of children who visited the emergency department or were hospitalized for EV-D68–associated respiratory illness was 3 years.

“[AFM] can be very severe and it can be very scary for the parents of children who have it,” Malley said, “but given the prevalence of enteroviruses in the community, you have to include it’s a relatively rare event in susceptible individuals. Why some get it and others don’t is unfortunately unclear at this moment.”

The CDC recommends that providers consider EV-D68 as a possible cause for acute, severe respiratory illness in children. If the cause of a respiratory illness in a severely ill patient is not clear, health professionals should test for RVs and EVs, if this is not already part of a typical diagnostic workflow, the agency said. Currently, there are no vaccines or specific treatments for RV or EV, and the CDC recommends supportive clinical management.

The advisory also urged providers 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.”

For any patient presenting with possible AFM, clinicians should collect samples from multiple sources, including cerebrospinal fluid, serum, stool, and a nasopharyngeal or oropharyngeal swab. Samples should be taken “as early as possible and preferably on the day of onset of limb weakness,” the alert said. There is currently no specific medicine for AFM, the agency said, though recommended interventions may vary for each patient.

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