Summary of Findings: Investigation of Acute Flaccid Myelitis in U.S. Children, 2014
Since September 2014, CDC and partners have been investigating reports of children across the United States who developed a sudden onset of weakness in one or more arms or legs with MRI scans that showed inflammation of the gray matter—nerve cells—in the spinal cord. This illness is now being referred to as acute flaccid myelitis.
From August 2, 2014 to January 14, 2015, CDC has verified reports of 107 children in 34 states who developed acute flaccid myelitis that meets CDC’s case definition. CDC continues to collaborate with partners nationally to investigate reported cases, risk factors, and possible causes of this condition.
- The median age of the children was about 7 years.
- Almost all of them were hospitalized; some were put on breathing machines.
- Most patients had fever and/or respiratory illness before onset of neurologic symptoms.
- About two thirds of the children who have been observed (median 19 days) after their illness reported some improvement in symptoms, while about one third showed no improvement. Only one of the children has fully recovered.
- We continue to test specimens from these patients for a wide range of pathogens that can result in this syndrome.
See CDC’s MMWR Acute Flaccid Myelitis Among Persons Aged ≤21 Years — United States, August 1–November 13, 2014 for more information about cases confirmed through November 13, 2014.
The specific causes of this illness are still under investigation. However, these cases are most similar to illnesses caused by viruses, including
- enteroviruses (polio and non-polio),
- West Nile virus and similar viruses, and
Among possible causes, we’re investigating whether the cases of acute flaccid myelitis may be linked to an outbreak of severe respiratory illness caused by enterovirus D68 (EV-D68) that the U.S. experienced in 2014. However, enteroviruses rarely cause encephalitis and myelitis. Rather, they most commonly cause mild illness, and sometimes aseptic meningitis.
- We are aware of only two published reports of children with neurologic illnesses confirmed as EV-D68 infection from cerebrospinal fluid testing.
Every year, children in the United States develop neurologic illness with limb weakness, and often the causes are not identified. Such illnesses can result from a variety of causes, including viral infections, environmental toxins, and genetic disorders, and Guillain-Barre syndrome, a neurologic disorder caused by an abnormal immune response that attacks the body’s nerves.
- requesting that healthcare professionals be vigilant for and report cases of acute flaccid myelitis to CDC through their state or local health department
- verifying reports of cases of acute flaccid myelitis using our case definition
- working with healthcare professionals and state and local health departments to investigate and better understand the cases of acute flaccid myelitis, including potential causes and how often the illness occurs
- testing specimens, including stool, respiratory and cerebrospinal fluid, from the children with acute flaccid myelitis
- providing information to healthcare professionals, policymakers, general public, and partners in various formats, such as the Morbidity and Mortality Weekly Report, health alerts, websites, social media, and presentations
- pursuing a multi-pronged approach to further explore the potential association of acute flaccid myelitis (AFM) with enterovirus D68 (EV-D68) and other etiologies as well as risk factors for AFM. This includes
- planning a potential case control study and
- testing specimens from AFM cases for a wide range of viruses that may be associated with this clinical presentation and testing to possibly detect previously unrecognized pathogens.
- The protocols have not been finalized for most of these activities.
If your child appears to have a sudden onset of weakness in arms or legs, parents should contact a healthcare provider to have their child assessed for possible neurologic illness.
Being up to date on all recommended vaccinations is the best way to protect yourself and your family from a number of diseases that can cause severe illness and death, including polio, measles, whooping cough, and acute respiratory illnesses such as influenza.
You can help protect yourselves from infections in general by
- washing your hands often with soap and water,
- avoiding close contact with sick people, and
- disinfecting frequently touched surfaces.
You can protect yourself from mosquito-borne viruses, such as West Nile virus, by using mosquito repellent, and staying indoors at dusk and dawn, which is the prime period that mosquitoes bite.