There were few answers, though, to soothe the fears of worried parents.
What causes AFM? Why do some children get the illness and others do not? Is it caused by a virus? If so, which one?
The federal agency has come under increased pressure from parents and doctors to find the cause of the mysterious illness, which has largely affected children and left many paralyzed.
Several parents recently spoke with CNN and accused the CDC of underreporting deaths.
“As a mom, I know what it’s like to be scared for your child,” said Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, during a briefing on Tuesday. “And I understand that parents want answers.”
Right now, though, science doesn’t give us an answer.
She admitted that health officials do not understand what triggers AFM in some children or understand the long-term consequences of the illness.
Possible factors can include viral infections such as enterovirus and West Nile virus, environmental toxins and a condition where the body’s immune system attacks and destroys body tissue that it mistakes for foreign material.
AFM specifically affects the area of the spinal cord called gray matter and causes muscles and reflexes to become weak.
Of the confirmed cases, most were involved children between the ages of 2 and 8 years old and about half were male. Almost all of the children had a fever and/or respiratory illness three to 10 days before experiencing limb weakness.
In nearly all of the cases, an upper limb was involved.
So far this year, there have been no known deaths, she said. However, Messonnier admitted that a lag exists between when a patient is hospitalized and when the case makes its way through the reporting process.
Meanwhile, the CDC has instituted several initiatives to quickly find answers, such as raising physician awareness about the illness, increasing its network of neurologists and asking state health departments to cross reference cases of AFM with death registries, including for previous years. CDC has also created a national AFM task force of experts.