Doctors believe they’ve narrowed down the cause of the myelitis, but the Centers for Disease Control is unconvinced.
As cases of acute flaccid myelitis, or AFM, a rare condition that causes paralysis, continues to affect children nationwide, doctors say that there’s compelling evidence that a virus called enterovirus D68, or EV-D68 is the main cause.
But the CDC does not believe that they can definitively say EV-D68 is the source of AFM. In a press conference on Oct. 16, Dr. Nancy Messonnier, the director of the National Center for Immunization and Respiratory Diseases at the CDC, said that the increase of AFM patients — there are 72 confirmed cases at the moment — “is a mystery.”
“We have not been able to find the cause for the majority of these AFM cases,” Messonnier said. “There’s a lot we don’t know about AFM, and I am frustrated that despite our efforts we haven’t been able to identify the cause of this mystery illness.”
The CDC has been searching for the root cause of AFM cases since 2014, the first time there was an increase in patients with the disease. This coincided with an outbreak of EV-D68.
“It’s puzzling that four years later CDC has not confirmed the etiology of these cases,” Dr. Ali Khan, dean of the University of Nebraska Medical Center College of Public Health and a former director of CDC’s Office of Public Health Preparedness and Response, told NBC News. “Continuing to frame this as a mystery after so many years doesn’t do the public health any justice.”
And several CDC advisors say that the organization needs to look deeper into enteroviruses like EV-D68.
“The CDC really seems to be out of sync with the conclusions that most scientists are coming to. We feel like we’re not being listened to,” Dr. Keith Van Haren, one of the CDC advisers on AFM and an assistant professor of neurology at the Stanford University School of Medicine, told CNN. “We don’t understand how the CDC has arrived at the place where they’re at.”
“This is the CDC’s job. This is what they’re supposed to do well. And it’s a source of frustration to many of us that they’re apparently not doing these things,” Dr. Kenneth Tyler, a professor and chair of the department of neurology at the University of Colorado School of Medicine and another adviser to the CDC on AFM, added to CNN.
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Of the 72 confirmed cases, the average age of patients is just 4 years old, and 90 percent of patients are 18 years or younger. AFM targets the nervous system and the spinal cord, which leads to the paralysis, along with muscle weakness and respiratory failure.
The CDC said that they’ve confirmed that AFM is not from the polio virus, but they are still searching for the cause.
“Despite extensive laboratory testing, we have not determined what pathogen or immune response caused the arm or leg weakness and paralysis in most of these cases. We don’t know who might be at a higher risk of developing AFM, or the reasons why they would be at a higher risk. And we don’t fully understand the long-term consequences of AFM,” Messonnier said. “We know that some patients diagnosed with AFM recover quickly, and some continue to have paralysis and require long-term care.”
But, she emphasized, AFM is still extremely rare.
“Overall the rate of AFM is less than one in a million, and that’s why we say this disease is incredibly rare,” she said.