WASHINGTON (NBC) — The Centers for Disease Control and Prevention said Tuesday it has received reports of 127 suspected cases of a polio-like condition called acute flaccid myelitis or AFM.
So far, 62 cases have been confirmed in 22 states, the CDC said. That makes 2018 look like it might end up being a year with more cases than usual, the CDC’s Dr. Nancy Messonnier told reporters.
It’s still not clear what is causing the condition, which can develop after a viral infection.
“We have not been able to find the cause of the majority of AFM cases,” Messonnier said. “We have detected enterovirus in several of these individual cases.”
None of the specimens has tested positive for polio virus, however. Polio was eradicated in the U.S. by vaccination. “AFM can be caused by other viruses such as enterovirus and West Nile virus as well as environmental toxins and autoimmune disease,” Messonnier said.
“We are actually looking at everything. We are looking beyond the normal infectious diseases that can cause this.”
AFM grabbed attention in 2014, when 120 cases were reported nationally. The CDC says it counted 22 cases in 2015, 149 cases in 2016 and 33 cases in 2017. That appears to indicate an every-other-year pattern.
The CDC does not name states with confirmed or suspected cases. NBC News had done its own unofficial survey of state health officials and found 87 confirmed or suspected cases in 26 states.
It takes some time to investigate each case, Messonnier said. To confirm a case requires not only that a child have symptoms of limb weakness or paralysis, but a magnetic resonance imaging (MRI) scan that shows specific damage in the spinal cord.
Depending on which part of the spine is damaged, different muscles can become weak or paralyzed.
This can cause a range of symptoms, from difficulty lifting an arm to severe weakening of the muscles used in breathing. That can require use of a ventilator to help the patient breathe.