COLUMBUS (WCMH) — Nationwide Children’s Hospital confirms one of its child care employees has tested positive for COVID-19 coronavirus.

The hospital’s child care center has been closed until further notice.

According to the hospital, the affected employee recently worked for two days while largely asymptomatic and called in ill Wednesday morning upon experiencing symptoms. She was immediately tested on Wednesday using Nationwide Children’s on-site testing center and lab.

The employee worked with two other staff members to care for 11 children. The staff and families of the 11 children have been notified and were requested to isolate at home for 14 days while they are monitored for symptoms, according to the hospital.

“Although no other children are believed to have had contact with this employee, approximately 150 other families whose children are served by the center were notified of these events and will be monitored by the hospital,” the hospital said in a statement.

The hospital says the employee followed all appropriate procedures, including temperature checks prior to each day at work. The employee’s self-reporting of symptoms resulted in the earliest possible detection, according to the hospital.