A rare disease similar to polio appears to be spiking. Six children from Washington have been hospitalized so far this year.

All told, 16 states have confirmed a total of 38 cases of acute flaccid myelitis in 2018.

It’s not a new condition, but the Centers for Disease Control and Prevention says the increase is not normal.

Michelle Holshu, an epidemiologist with the Washington State Department of Health, said all the local cases involve children younger than 6 who had respiratory illnesses the week before developing AFM.

“So while we don’t know what causes AFM, its still a good reminder to do all of the things you’d usually do during cold and flu season to keep you and your family safe: things like washing your hands, avoiding contact with sick people, cleaning surfaces with disinfectant … could be important,” she said.

Oregon hasn’t had any cases of AFM this year. But it had three in 2014 and three more in 2016.

Few people die from the disease, but it can put people on a ventilator or trigger neurological problems.

The CDC says being up to date with polio vaccinations provides some immunity.