News of a mysterious polio-like illness infecting children began to emerge across the United States in 2014.
Physicians and other health professionals were baffled by what was causing kids to arrive at hospitals with weakness in their arms or legs, difficulty breathing or swallowing and sometimes paralysis. They didn’t know how to prevent it. Known as acute flaccid myelitis, the disease attacks a person’s nervous system, specifically the spinal cord.
The Centers for Disease Control and Prevention (CDC) has been working since 2014 with state and local health officials to study the disease and raise awareness among doctors and other healthcare providers.
Dr. Tracy Ayers (PhD, ’16) is on the CDC’s team of epidemiologists and microbiologists that is gathering information about acute flaccid myelitis and researching its potential causes.
“The difficulty is that the disease is really rare,” said Ayers, a second-year officer in the CDC’s Epidemic Intelligence Service, an elite two-year training program for disease detectives. “That’s challenging because there is limited information to work with.”
Ayers traveled to Arizona, which saw a cluster of cases of acute flaccid myelitis in 2016, when the disease was also on the rise nationally. She interviewed young patients and their parents to learn about the onset of the illness and how their symptoms developed. Recovery can be slow, and in some reported cases, children may continue to suffer serious symptoms as much as two years after falling ill.
“We’re in the very early stages of understanding what this disease is and what’s causing it,” Ayers said. “I have to say, something like this—it’s easy to get passionate about, especially after seeing firsthand how it’s affecting families.”
The CDC lab has tested for more than 250 different organisms but hasn’t found a prime suspect yet.
Many epidemiologists initially suspected the disease was tied to a respiratory virus known as EV-D68. At the same time acute flaccid myelitis cases were gaining national recognition, there was a nationwide outbreak of EV-D68, which is an enterovirus. Enteroviruses are viruses that can spread through saliva or feces and are more common in the summer and fall.
“We know that enteroviruses have the potential for causing these types of symptoms, although it’s very rare,” said Ayers. “But, because we haven’t consistently found EV-D68 in our tests, we are continuing to investigate a variety of possible causes.”
What’s more, cases of acute flaccid myelitis were reported in 2015 and 2016 when there were not outbreaks of EV-D68.
Ayers’ team is expanding its investigation to look at potential links to other common viruses, as well as to non-infectious diseases.
“We’re looking at whether it has something to do with the immune system,” Ayers said. “So maybe it turns into a neurological condition only for certain individuals because of how their bodies respond, what their immune responses are and how they react to the infection.
“From the epidemiology standpoint, it’s fascinating,” she said. “It’s a puzzle to be solved.”