A Seattle Children’s hospital nurse has been diagnosed with measles after she cared for a patient who had also been diagnosed with the highly contagious disease, health officials said Monday.

The nurse, who is in her 20s and works in the inpatient units, was potentially contagious while working from July 8 through July 11. She was also at Metropolitan Market on Sand Point Way on July 8 and Safeway in Kenmore on July 10, according to Public Health – Seattle & King County.

She is fully vaccinated and wore appropriate protective equipment while caring for the ill child, Seattle Children’s said in a statement. The patient was in the hospital’s emergency department on June 22, June 25 and June 26, but didn’t show symptoms of measles until the third visit. The child was immediately put in isolation, the hospital said.

The hospital is notifying patients, families and staff members who may have been exposed.

The specific exposure times are listed here.

The nurse is the 10th measles case in King County since May, according to the health department.

Measles is highly contagious and can be fatal for people with weakened immune systems. The virus causes fever, rash and red, watery eyes. It’s highly contagious; A person can contract measles up to two hours after the infected person had left the area.

Symptoms appear from seven days to three weeks after the last exposure. A rash may appear 10 to 12 days after exposure.