If you think you’ve been exposed to measles, do not show up at a clinic or hospital without calling first, Public Health — Seattle & King County said. To avoid possibly spreading measles, limit contact with others and wear a well-fitting mask if you need to go to a health care facility, the department said.

Measles is extremely infectious, and health officials have identified several potential exposure locations across the county.

Public health officials have listed several locations in Seattle and the Eastside where the infected infant was present while contagious.