Clark County public health director, Dr. Alan Melnick, said the measles outbreak is still evolving.
Canada could experience the same type of measles outbreaks that Washington and NY states are now facing because of low vaccination rates and the highly contagious nature of the virus, public health experts warn.
Officials say those people were in close contact with the only other person confirmed to have the measles in Multnomah County.
Some 82,596 people in 47 of 53 countries contracted measles, the highest number this decade and three times the figure in 2017.
"I think we need to strengthen our legislation", she told reporters.
Clark County Public Health is continuing its measles outbreak investigation.
Vaccination rates for measles, mumps and rubella in Ukraine fell sharply over a number of years during its conflict with Russian Federation, reaching 31% in 2016 - among the lowest in the world.
Washington and OR are among 17 states that allow non-medical exemptions from vaccination requirements for school entry, according to the National Conference of State Legislatures. Thirteen additional cases were suspected. To prevent illness, one dose of MMR vaccine must be given to unimmunized people within 72 hours of exposure.
Non-Medical Exemptions and Measles Hotspots In June 2018, Contagion® reported on a study published in the journal PLOS Medicine, conducted by Peter Hotez, MD, PhD of Baylor College of Medicine's National School of Tropical Medicine in Houston, Texas, and colleagues.
In the third week of January, 644 children aged 1-18 were vaccinated against measles in the county. Only 81% of 1 to 5 year olds in the county have received a dose of MMR, according to Clark County, Washington Public Health.
MMR vaccine rates in two areas in the Pacific Northwest, which has been at the epicenter of a measles outbreak, are surging as people rush to protect themselves and their children from the virus.
What Other Cities Are at Risk?Forty-two patients were not immunized against the virus, while health officials had not verified the immunization status of six patients.
The "anti-vaxxers" movement still thrives in many pockets of the United States.
According to the World Health Organization (WHO), vaccination is one of the most cost-effective ways of avoiding disease - it now prevents 2-3 million deaths a year, and a further 1.5 million could be avoided if global coverage of vaccinations improved. "There are some more isolated, unvaccinated communities, for example the Amish, where we haven't seen a major outbreak".