Patients and visitors to UW Hospital are being alerted that they may have been exposed to the measles last weekend, according to hospital officials. It's not clear how many peole may have been exposed to the highly contagious virus. On Saturday afternoon, an adult patient went to the e-r with symptoms and was discharged on Monday. Lab results came in on Wednesday, confirming they were infected with measles virus. The staff at UW is alerting those who may have been exposed.