The Slatest

CDC Confirms Surge in Cases of Polio-like Disease Mostly Affecting Children

Logo for the Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention updated its recent numbers for confirmed cases of acute flaccid myelitis.
Kevin C. Cox/Getty Images

A rare, polio-like disease is emerging in almost half of the United States, the Centers for Disease Control and Prevention said Tuesday.

There have been 62 confirmed cases this year of acute flaccid myelitis or AFM, a serious condition most common in children that affects the nervous system. The CDC has received a total of 127 reports of suspected cases in so far 2018.

“CDC recently received increased reports for [patients under investigation] with onset of symptoms in August and September,” the investigation said.

Chart showing number of confirmed AFM cases by year of illness onset from 2014 to 2018
Number of confirmed AFM cases by year of illness onset from 2014 to 2018
Centers for Disease Control and Prevention

Acute flaccid myelitis causes “weakness in the arms or legs” and like polio, can lead to paralysis or even death. AFM symptoms also include facial droop, difficulty swallowing, and slurred speech.

The 62 cases represent a steep rise from the 33 cases confirmed last year and follows a pattern observed since 2014, in which numbers surge every other fall. The Texas Department of State Health Services had also previously noted that AFM cases have a “biennial pattern” and “generally peak in the months of September and October.”

The CDC has seen an increase in AFM cases since 2014. Although the CDC said it is “currently difficult to interpret trends of the AFM data,” it’s interesting to note that AFM might be linked to other enteroviruses.

The increase in 2014 and 2016 coincided with the national outbreak of enterovirus D68, a respiratory illness most likely to infect children in the summer and fall. It may appear like the common cold, but when severe, it can cause “wheezing and difficulty breathing.” In both 2014 and 2016, some patients with AFM were also found with the virus EV-D68 in their system, the CDC report said.

Take Colorado, for example. During August to October 2014, 11 patients in the state were diagnosed with AFM, with four of them also infected with EV-D68. A CDC study later found that an “association exists between EV-D68 and acute flaccid myelitis.”

“It’s notable that this clustering or outbreak of acute flaccid myelitis occurred against the backdrop of this large national outbreak of EV-68 respiratory infection among children,” said James Sejvar, a neuro-epidemiologist with the CDC in a December 2014 article by the Center for Infectious Disease Research and Policy.

This year, 11 out of 15 AFM patients in Colorado tested positive for a similar virus called enterovirus A-71. EV-A71 is another virus common in the summer and fall and can cause fevers, sores, and meningitis.

Despite the recent increase, AFM is still considered a rare condition, with a total of 286 confirmed cases from 2014 to 2018. That’s “fewer than one in a million children in the U.S.,” said Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, in a telebriefing Tuesday.