LOS ANGELES — A polio-like illness has afflicted a small number of children in California since 2012, causing severe weakness or rapid paralysis in one or more limbs.

The Los Angeles Times reports that state public health officials have been investigating the illness since a doctor requested polio testing for a child with severe paralysis in 2012. Since then, similar cases have sporadically been reported throughout the state.

Dr. Carol Glaser, leader of a California Department of Public Health team investigating the illnesses, called the doctor’s request “concerning” because polio has been eradicated in the U.S. and the child had not traveled overseas.