Clinicians should be on alert for a spike in cases of acute flaccid myelitis (AFM) over the next several months.
The rare but serious condition characterized by sudden limb weakness has peaked every other year since 2014. Centers for Disease Control and Prevention (CDC) Director Robert Redfield, M.D., said Tuesday he is uncertain how the circulation of SARS-CoV-2 and influenza this fall will impact incidence of AFM or how quickly people seek care but stressed “timing is critical.” A new report found that in 2018, 35% of children with AFM were not hospitalized until two or more days after onset.
“When clinicians recognize AFM early, they can quickly hospitalize patients, monitor vital signs and pulmonary function for signs of deterioration, collect specimens and order an MRI,” Dr. Redfield said. “We’ve seen that when this is done early, there’s a better chance of detecting the cause of AFM and distinguishing it from other conditions which can cause limb weakness.”
Most cases of AFM occur in August through November. Multiple viruses can cause AFM including West Nile, adenovirus and nonpolio enteroviruses. Enterovirus D68 has likely been a driver of the spikes in AFM, according to the CDC.
In a new Vital Signs report, authors from the CDC detail the 2018 outbreak that included 238 patients in 42 states. The median age was 5 years and 58% were male.
About 92% of the AFM patients in 2018 had fever or respiratory illness about six days before limb weakness. The most common symptoms during clinical evaluation in addition to limb weakness were gait difficulty, back or neck pain, fever, limb pain and headache. About 94% had spinal cord lesions, and 86% had thoracic cord lesions.
Clinicians who suspect AFM should collect cerebrospinal fluid, serum, stool, nasopharyngeal and/or oropharyngeal swabs immediately and order a brain and spinal cord MRI. They also should report cases to their state health department.
In 2018, 54% of patients were admitted to intensive care, and 23% required endotracheal intubation and mechanical ventilation.
There is no recommended treatment for AFM, but the most common in 2018 were steroids and intravenous immunoglobulin. Thomas Clark, M.D., M.P.H., CDC deputy director of the Division of Viral Diseases,said the CDC is continuing to study long-term outcomes, although it appears many patients will have a permanent disability.
“It’s really important kids get into rehabilitation,” he said. “Early and aggressive physical therapy, occupational therapy can help strengthen the function they do retain and help them go about their lives with the best functioning possible.”
The CDC does not know why a small number of children with common viruses progress to AFM. Dr. Clark recommended families take standard precautions to prevent infection with these viruses, including frequent handwashing, covering their cough, sanitizing surfaces and getting a flu vaccine.