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.

Health officials in King County are urging caution following the first confirmed case of measles in Washington state this year. The King County infant, diagnosed with measles after recent overseas travel,

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