The Washington State Department of Health (DOH) is leading a joint investigation into reports of nine children who were admitted to Seattle Children’s Hospital with acute neurologic illnesses. The Department of Health has confirmed that eight out of the nine children have acute flaccid myelitis (AFM). Public Health Seattle & King County, Seattle Children’s Hospital, and the Centers for Disease Control and Prevention (CDC) are working with the Department of Health on the continuing investigation. A ninth child who died did not have AFM.

Image/ National Atlas of the United States
Image/ National Atlas of the United States

AFM is a rare condition that can be caused by many different things; it affects the nervous system, specifically the spinal cord. Symptoms typically include sudden weakness in one or more arms or legs, along with loss of muscle tone and decreased or absent reflexes.

Scientists at CDC are working to determine the exact cause of AFM. The exact cause of AFM is unknown. Many viruses and germs are linked to AFM, including common germs that can cause colds and sore throats, and respiratory infections. It can also be caused by poliovirus and non-polio enteroviruses, mosquito-borne viruses (such as West Nile virus or Zika virus) and autoimmune conditions.

The children with AFM arrived to Seattle Children’s Hospital with their symptoms and did not acquire AFM at the hospital. The eight children confirmed to have AFM were admitted to the hospital with a range of types and severity of symptoms, but all had a loss of strength or movement in one or more arms or legs. The children are from five counties [King County – 3 children, Pierce County – 1 child, Franklin County- 2 children, Whatcom County – 1 child, and Snohomish County -1 child]. The children range in age from 3 to 14 years. Three of the eight cases are currently hospitalized at Seattle Children’s Hospital and five have been released.  Out of respect for patient privacy, no further information about specific patient cases can be provided.

“Patient safety is our top priority at Seattle Children’s, and parents should know that it is safe to bring their children to the hospital,” said Dr. Mark Del Beccaro, chief medical officer at Seattle Children’s Hospital. “We are using appropriate standard infection control, including putting patients with symptoms of active respiratory infections in isolation so they do not have contact with any other patients.”

Public Health Seattle & King County, the DOH and the CDC continue to monitor and investigate this issue, and determine if an underlying cause can be identified. However, the cause of any individual case of AFM can be hard to determine, and often, no cause is found. The CDC makes the final determination regarding whether cases are classified as AFM or not.

“At this point there isn’t evidence that would point to a single source of illness among these cases,” said Dr. Scott Lindquist, state infectious disease epidemiologist at the Department of Health. “If more information becomes available, we’ll keep the public informed.”

There were no cases of AFM reported in Washington State in 2015, and in 2014 there were two. Since September 2016, there have been 89 cases of AFM in 33 states across the U.S. so far this year.