New Research Explores Why Kids Are Vulnterable to AFM

In 2014, hundreds of children began showing signs of a polio-like illness, leaving infectious disease specialists searching for answers. Early clusters originated in Colorado before spreading across the country. Shortly after, the Centers for Disease Control and Prevention coined a new diagnosis: acute flaccid myelitis, or AFM.  

Two years later, after another spike in cases, researchers at Children's Hospital Colorado identified enterovirus D68 (EV-D68) as the primary cause of AFM. And more than a decade later, the team continues to push the research forward.  

Sadie Meller, MD, PhD, a pediatric neurology resident at Children’s Colorado, recently received funding from the Colorado Stimulating Access to Research in Residency (StARR) Program to answer an important question: Why do children seem more likely than adults to develop paralysis after an EV-D68 infection?  

To do this, Dr. Meller is looking at microglia, immune cells that live in the brain and spinal cord and act as the central nervous system's primary defense system. Microglia make up 5% to 10% of all cells in the brain. Dr. Meller is investigating how these cells respond to an EV-D68 infection. She's also exploring age-related differences by comparing immune responses in young and old murine models.  

"It's been really fascinating to see how robust the microglia response is,” Dr. Meller says. “It's immediately apparent when looking through a microscope how many microglia are there and how big and active they get in combatting the viruses. I'm excited to keep researching their role in the development of paralysis after infection."  

By understanding how immune cells respond, Dr. Meller hopes to understand why AFM develops and identify future treatment or prevention strategies. While AFM outbreaks have sharply declined since 2020, the condition can cause lifelong paralysis, making research like Dr. Meller's critical.