Two children have been diagnosed with a rare neurological condition called acute flaccid myelitis, which can lead to paralysis, the Washington State Department of Health said today.
At least nine cases have been identified as part of a potential cluster of AFM cases, including the two confirmed cases. One child, who died after developing neurological symptoms, has not been confirmed to have had developed AFM, according to the Washington State Department of Health.
The children between the ages of 3 to 14 in Washington state were hospitalized at Seattle Children's Hospital after developing symptoms including weakness or loss of movement in one or more of their limbs.
Five of the children were released from the hospital, three remain hospitalized and one died after developing the symptoms, the Washington State Department of Health said Monday. The family said the child died on Sunday. No link between any of the cases has been detected, according a spokeswoman for the Washington State Department of Health.
Due to the nature of the symptoms, authorities are investigating if they have identified a cluster of AFM. The syndrome is a rare condition that is not contagious on its own and affects the nervous system, specifically the spinal cord. It can occur due to various causes including viral infections. Since AFM is often caused by a variety of viruses, officials are looking to see if any viral infections in the area may have led to the cluster.
CDC officials said today that they are "concerned about the increase in cases in recent months." Since the start of this year through September, there have been 89 cases of AFM in 33 states, according to the CDC. In 2015, there were just 50 cases. In 2014, 120 cases of AFM were reported throughout the U.S. between August and December. At the time, the CDC and other health agencies were investigating the enterovirus D68.
Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said the goal will be to definitively diagnose the children with AFM and then search for a potential cause.
"The first thing the investigators will do, they will look at clinical records to see if they fit the CDC definition of AFM," Schaffner said. "They will simultaneously go to all of these patients and make sure that they have the best possible specimens to be sent to lab to establish viral diagnosis."
If the child who died had signs of viral infection, it may help the CDC figure out if other children are at risk for developing AFM, Schaffner said.
"They will look to see if they find evidence of the virus in the nervous tissue," Schaffner explained.
In 2014, dozens of children developed AFM around the time an outbreak of a respiratory virus called enterovirus D68 started to spread through the country. In general, certain enteroviruses, such as the polio virus, increase the risk that patients will develop AFM. However, after the 2014 enterovirus D68 outbreak, the CDC has not "consistently detected a pathogen" in the spinal fluid of infected patients that linked the virus to AFM cases.