Another case of Acute Flaccid Myelitis (AFM), which closely resembles polio and causes partial paralysis in children, has been reported in Illinois, the state's Department of Public Health confirmed.
The latest case brings the number of suspected cases in Illinois to 10, the department said Friday. All of the cases are among children in northern Illinois.
"The underlying cause(s) of AFM is not known," the department said in a statement. "CDC has been actively investigating AFM and continues to receive information about suspected AFM cases."
AFM is a puzzling condition that causes partial paralysis in children. It is on the uptick in parts of the U.S., with six cases under investigation in Minnesota and 14 reported in Colorado, health officials said this week.
It was first widely recognized in 2014, when 120 children were diagnosed, NBC News reported.
So far this year, the Centers for Disease Control and Prevention says there have been 38 confirmed cases of the polio-like condition across 16 states.
Symptoms of the disease can include a sudden onset of limb weakness and loss of muscle tone and reflexes, as well as facial droop/weakness, difficulty moving the eyes, drooping eyelids and difficulty with swallowing or slurred speech.
Various viruses can cause AFM, including West Nile virus and enteroviruses. The disease can be transmitted via mosquitoes, the DPH says.