Findings from the CDC show children with acute flaccid myelitis had a 10-fold greater risk for having enterovirus D68 infection during a cluster of cases in Colorado in 2014.
“From Aug. 8, 2014, through Oct. 14, 2014, a cluster of cases of acute limb weakness, cranial nerve dysfunction, or both, in children with characteristic clinical and radiologic findings of myelitis were identified at Children’s Hospital Colorado,” Negar Aliabadi, MD, epidemic intelligence service officer at the CDC, and colleagues wrote. “Although no etiology for the neurologic disease was identified among the Colorado cluster of patients, EV-D68 was found in the nasopharynx of 45% of these patients.”
Researchers from the CDC, Children’s Hospital Colorado and the University of Colorado conducted a retrospective case-control study of children (n = 11) who had been treated at the hospital and another nearby institution for respiratory illnesses. They collected nasopharyngeal specimens for pathogen testing in Colorado within a 2-month period to find a correlation between different upper respiratory diseases and the presence of EV-D68.
Aliabadi and colleagues established two control groups: The first group included children who were treated as outpatients and for whom nasopharyngeal specimens were tested by multiplex respiratory pathogen panel-PCR (RPP-PCR). The second group included outpatients whose nasopharyngeal specimens were collected and tested by PCR for Bordetella pertussis. Case patients aged younger than 21 years with acute neurologic illness, characterized by spinal cord lesion findings by MRI, no identified etiology and focal weakness of one or more limbs, were considered to have acute flaccid myelitis.
The researchers tested two models for comparisons between acute flaccid myelitis and the controls. The first model tested the association between EV-D68 and acute flaccid myelitis, while the second tested the association between enterovirus and rhinovirus only.
Among 203 specimens from ICU patients with acute flaccid myelitis, Aliabadi and colleagues identified 49% that were positive for EV-D68. In addition, acute flaccid myelitis diagnoses peaked and coincided with those of EV-D68 respiratory infections at Children’s Hospital Colorado during that period. No predominant virus was detected in the enterovirus/rhinovirus species.