(Portland, OR) - Health officials are warning patients and staff about a possible measles exposure at a Vancouver clinic. Clark County Public Health says an unvaccinated child who had measles was at Salmon Creek Vancouver Clinic while contagious. Officials say the exposure happened July 17 between 1:30 p.m. and 5:30 p.m. at the clinic on Northeast 139th Street. People who were exposed and are not vaccinated are being asked to avoid public places for three weeks and contact a health care provider if symptoms develop.