CDC officials worried about rise in rare, mysterious condition

Federal health officials are worried about an increase in a mysterious and rare condition that mostly affects children and can paralyze arms and legs, with 127 confirmed or suspected cases reported as of Tuesday.

Of those, 62 cases of acute flaccid myelitis, or AFM, have been confirmed in 22 states, according to Nancy Messonnier, a top official at the Centers for Disease Control and Prevention. More than 90 percent of the confirmed cases have been in children 18 and under, with the average age being 4 years old.

There is no specific treatment for the disorder, and long-term outcomes are unknown. The rare but serious disorder affects a person’s nervous system, specifically the spinal cord. Neurological conditions like it have a variety of causes, such as viruses, environmental toxins and genetic disorders.

The increase in cases has been happening since 2014, with the number of cases spiking in August and September, she said in a news briefing with reporters. One child with the disorder died in 2017. Officials have been baffled by the increase, and are starting to count suspected cases as well as confirmed ones to better anticipate increases in confirmed cases over the coming months.

“We understand that people, particularly parents, are concerned about AFM,” she said. Despite extensive laboratory and other testing, CDC has been unable to find the cause for the majority of the cases. “There is a lot we don’t know about AFM, and I am frustrated that despite all of our efforts, we haven’t been able to identify the cause of this mystery illness.

“We know this can be frightening for parents, and I know many parents want to know what signs and symptoms they should be looking out for in their children,” she said. Parents should seek medical care immediately if their child develops sudden weakness or loss of muscle tone in the arms and legs.

Some patients diagnosed with this condition have recovered quickly but others continue to have paralysis and require ongoing care, she said.

The CDC began tracking the condition in 2014, when there were 120 confirmed cases. Then in 2016, there were 149 confirmed cases. Officials said it’s too early to know whether the total cases for 2018 will surpass those previous years. But the data reported Tuesday represents “a substantially larger number than in previous months this year,” Messonnier said.

Parents and clinicians should remember that this is a rare condition, affecting less than one in a million people, she said. “As a parent myself, I understand what it’s like to be scared for your child,” she said. “Parents need to know that AFM is rare even with the increase in cases we are seeing now.”

Still, because this is a “pretty dramatic disease,” Messonnier said, health officials want to raise awareness about the symptoms to ensure parents seek medical care immediately if their children show a sudden onset of weakness in their arms and legs.

The agency knows that poliovirus is not the cause of these cases because the CDC has tested every single stool specimen from patients and none have tested positive for poliovirus. Messonnier said West Nile virus, which had been listed as a possible cause on the CDC’s website, is not causing the illnesses.