The revelation prompted public health officials in Oregon's Deschutes County and in Hawaii to issue alerts, although no cases were confirmed in either location.
"I would hope that this ends soon, but this could go on for weeks, if not months", Alan Melnick, public health director for Clark County told The Associated Press. According to the Washington State Department of Health, people who are exposed to measles and have not had the vaccine or the disease itself are very likely to get measles. That raises the possibility of more cases among the unvaccinated. "The recommended two doses of the measles vaccine provide even greater protection - 97 percent".
The Centers for Disease Control and Prevention (CDC) declared measles "eliminated" from the United States in 2000, but adherents of an anti-vax movement, tied in part to concerns about links between vaccines and autism, has led many parents to skip the shot, opening the door to potential infection.
So far, none of the patients whose immunization status has been confirmed got their measles vaccination.
The AP noted that Clark County, Washington, has a vaccination rate of 78 percent, which is too low to protect those with compromised immune systems, those who can not get vaccinated because of medical problems, or those who are too young. There have also been three reported cases in Atlanta.
Sleet, snow and ice forecast
Heavy snow is forecast to hit the United Kingdom tonight as the Big Freeze launches another bone-chilling assault on the country. The rest of the United Kingdom is expected to see the impact from midday, with up to 10cm (4in) of snowfall on higher ground.
In an effort to stop the spread of the illness, the Health Department and partners have provided more than 16,000 vaccinations.
Nearly everyone who is not immune will get measles if they are exposed to the measles virus. "We know that what we are doing is not working because we're seeing the measles outbreak".
Measles often begins with a high fever, cough, runny nose and red, watery eyes.
The Chelan-Douglas Health District clarified a Thursday news release indicating state law requires children or staff of public and private schools or child care show proof of immunity to Mumps, Measles and Rubella if the disease is present. Of these, approximately 500,000 cases were reported each year to CDC; of these, 400 to 500 died, 48,000 were hospitalized, and 1,000 developed encephalitis (brain swelling) from measles.