What Is Causing Mysterious Paralysis Cases in Children?

May 12th, 2017

By Gary Evans, Medical Writer

The mother said that her daughter felt fine during the day, gradually began feeling weak and ill, and by bedtime that evening had become hypersensitive and could not touch anything without experiencing pain.

“By the time it came time to go to bed, the bed hurt,” says Tracy Ayers, MD, an epidemiologist in the CDC’s Epidemic Intelligence Service (EIS). “Everything hurt to touch. She couldn’t touch anything. So the mother put her in the bathtub because that felt better to have the water on her skin. At that point, she lost even more muscle tone and her head went a little floppy as well. So the mother was holding her in the bathtub, very scared, as you can imagine as a parent and not knowing what to do. That’s when she immediately took her to the emergency room.”

A cryptic polio-like illness of unknown etiology is increasing, causing more severe symptoms in younger patients than when it first emerged in 2014, Ayers reports. After a decline in cases in 2015, there was more than a four-fold increase last year, including patients that presented with altered mental status and needed mechanical ventilation.

“Acute flaccid myelitis (AFM) is characterized by a sudden onset of a limb weakness, meaning an arm or a leg may lose [strength] or may be difficult to move,” Ayers says. “Sometimes there’s facial drooping, sometimes there’s difficulty swallowing.”

The AFM syndrome emerged in 2014 in the U.S. in conjunction with an outbreak of Enterovirus D 68 (EV-D68), which was initially strongly suspected as the infectious etiology. However, EV-D68 has been identified in some cases of AFM, but is not present in others with identical symptoms, says Ayers, who presented the investigation recently in Atlanta at the annual EIS Conference.

“EV-D68 specifically is one of the many enteroviruses that we tested for,” she says. “A portion of the specimens do test positive for EV-D68, but we also have a portion that test positive for other enteroviruses and a large portion that don’t testify positive for any of those. I think at this time its inconclusive what is the definitive cause. But we will continue to look at EV-D68 as well as many other enteroviruses. We’re thinking about things that are maybe non-infectious as well.”

The investigation has taken on a sense of urgency because more recent cases are striking younger children with more severe clinical presentation. Ayers and co-investigators investigated a cluster of cases in children last year in Arizona, where she talked to the mother of the paralyzed child. When Ayers examined the child two weeks later, she was regaining a little bit of strength in her upper arms and was doing physical therapy.

“Unfortunately, she was only one case out of 134 for 2016,” she says.

Since the condition emerged, patients in some cases have fully recovered, and others remain at least partially symptomatic. No deaths have been attributed to AFM. Clinicians should raise their index for suspicion in such cases and report them promptly, she says.

“[We need to make sure] they’re reporting and suspecting AFM [and] collecting specimens as early as possible,” Ayers says. “It is a rare disease, but it’s such a severe one that we need as much information as possible.”

For more on this story see the June 2017 issue of Hospital Infection Control & Prevention

Gary Evans has written about infectious diseases, occupational health, medical ethics and a variety of other healthcare issues for more than 25 years. His writing has been honored with five awards for interpretative and analytical reporting by the National Press Club in Washington, DC