At least eight children in Washington state have been hospitalized with a rare neurological illness that state officials say is similar to polio, the Seattle Times reported. The children range in age from 3 to 14 and are all hospitalized at Seattle Children's Hospital.

The Centers for Disease Control and Prevention said the illness is caused by acute flaccid myelitis, an illness that affects the nervous system. One of the chief symptoms of the illness is limb weakness, according to Global News.

Dr. Scott Lindquist, an epidemiologist for communicable diseases in Washington state said that the condition is not life-threatening or contagious. One 6-year-old boy who was thought to have the illness died recently. Tests confirmed that he did not have AFM according to Global News.

The cluster of cases has alarmed officials in the state because in 2015 there were no reported cases of the illness. Washington state is not alone in an uptick in AFM cases. Since September 2016, there have been 89 cases of AFM reported across the country, according to AOL.

AFM can be caused by autoimmune issues as well as a host of viruses and germs such as the virus that causes the common cold, poliovirus, West Nile and Zika virus.

Officials are still unsure about what has caused so many children to come down with AFM in Washington. The CDC is investigating possible leads. Health officials say that the best way to prevent AFM is through hand-washing and flu vaccinations.