PORT ANGELES — Clallam County public health officials are awaiting test results on a possible fifth case of measles in the county this year.

Samples were sent to the state Public Health Laboratory in Seattle on Wednesday, Iva Burks, director of the Clallam County Department of Health and Human Services, said in a news release Thursday.

The person who has been tested is an adult relative of people who were diagnosed last month and who had been thought to be immune, the health department said.

No cases of the highly contagious disease have been confirmed in Jefferson County, and no tests are in the works, said Lisa McKenzie, communicable disease program coordinator for the county public health department, on Thursday.

The first Clallam County case was an adult man who was diagnosed

Feb. 1 and hospitalized at Olympic Medical Center in Port Angeles. Since then, a kindergarten student, another man and the 14-year-old sibling of the kindergartner were diagnosed with measles.

If there are no new measles cases in Clallam County through April 6, the local outbreak will be considered over because two incubation cycles will have passed.

Until laboratory results are available, public health officials are treating the possible fifth case as if it had been confirmed and are following up with people who might have been exposed, officials said.

“If you or your children are not up-to-date on your vaccinations, now is the time to act,” said Dr. Jeanette Stehr-Green, interim Clallam County public health officer.

Immunization clinics are offered by the Clallam County public health department at 111 E. Third St., Port Angeles. Call 360-417-2274 for information.

In Port Townsend, clinics are at the Jefferson County Public Health Clinic at 615 Sheridan St., which can be reached at 360-385-9400, and Jefferson Healthcare hospital’s primary care clinic at 915 Sheridan St. at 360-379-8031.