After a week without new cases, Clark County Public Health announced Thursday that four people are suspected of having measles.
Since the number of people diagnosed reached 70 between Oregon and Washington, there have been no new cases or even suspicious cases.
But now four people have enough measles symptoms for public health workers to send their blood for testing.
The measles vaccine may occasionally cause a harmless temporary rash, but it resembles measles. It is therefore necessary to perform blood tests to determine whether it actually does or does not involve measles.
The lull period is one of the longest since January 1, the date of the beginning of the epidemic. However, Dr. Alan Melnick, Clark County Public Health Officer, said that 21 days without a new case must pass before the outbreak can even be reviewed.
The vast majority of people diagnosed with measles are young children who have not been vaccinated. Clark County has confirmed 65 cases in the Vancouver area, and Multnomah County has identified four people with measles and one person who may have measles. A man from King County, Washington, also had measles.
Two doses of vaccine are 97% effective, and public health officials in Washington recommend to all unvaccinated people or to receive only one of them to receive both injections to avoid contracting the measles. The vaccine can reduce the risk of infection if it is obtained within 72 hours of exposure to the virus.
To help prevent the spread of the disease, health officials are asking people who think they have measles to call their doctor or health care provider before going to the hospital or doctor's office.
The Clark County Public Health Department now has a daily call center to answer questions regarding the outbreak at 360-397-8021.