AFM is rare but serious, characterized by sudden limb weakness and typically preceded
by respiratory illness or fever. Federal health officials have been trying to pinpoint
a cause of outbreaks, the largest of which have been occurring every other year since
2014. While the timing has coincided with outbreaks of EV-D68 and EV-A71, the viruses
often aren’t seen in AFM patients’ cerebrospinal fluid (CSF).
In a new study published in mBio, a team from Columbia University and the Centers for Disease Control and Prevention
(CDC) studied 13 children and one adult with AFM and five patients with non-AFM central
nervous system diseases using viral-capture high-throughput sequencing. Only one patient
from each group had enterovirus RNA in their CSF.
“Failure to detect viral RNA in CSF may represent absence of virus, low levels of
viral template, or sequence mismatch between viral template and primers or probes,”
Using the same 14 CSF samples from AFM patients, the team then took a more indirect
approach, looking for EV antibodies. They also studied samples from control groups
that included children and adults with non-AFM central nervous system conditions and
children with Kawasaki disease.
The antibodies were detected in the CSF of 11 of 14 (79%) AFM cases compared to three
of 26 (11.5%) in the control group.
“The presence in cerebrospinal fluid of antibodies to EV peptides at higher levels
than non-AFM controls supports the plausibility of a link between EV infection and
AFM that warrants further investigation and has the potential to lead to strategies
for diagnosis and prevention of disease,” authors wrote.
As research continues, public health officials have urged doctors to be on the lookout
for AFM. Since 2014, there have been 574 cases, typically occurring in late summer
or early fall. Physicians who suspect a patient has AFM should perform a workup, including
MRI and collection of respiratory, stool, serum and spinal fluid samples for testing. They also should quickly report suspected cases to their state or local