A nurse at Seattle Children's Hospital contracted the measles after caring for an infected patient, reports Q13 Fox.
The inpatient nurse was vaccinated against the measles and wore personal protective equipment when caring for the patient but still contracted the disease.
Seattle Children's says the nurse was potentially contagious while working night shifts from July 8-10.
"We are in the process of notifying patients, families and staff who may have been exposed, providing information about exposure dates, disease symptoms and offering preventative treatment if necessary," Seattle Children's said in a statement cited by Q13 Fox.