"The virus can stay in a room for two hours after someone with the disease has been in there".
Demand for measles vaccines leapt 500 percent last month in Clark County, Washington-a hotbed for anti-vaccine sentiment that has now become the epicenter of a ferocious measles outbreak.
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.
As of January 6, the county-which sits just north of the border from Portland, Oregon-has tallied 50 confirmed cases and 11 suspected cases of measles since January 1.
The confirmed case of measles is in a child residing in Western Bell County.
Measles infection typically causes a rash, fever, conjunctivitis (red eyes), cough or runny nose. But it can also lead to serious, life-threatening complications, including blindness, inflammation of the brain and pneumonia.
"Vaccination is the most effective way to prevent measles", said Dr. Matt Richardson, Director of Public Health.
Two adults died from measles in 2017 in the UK.
Three Multnomah County youths have measles, bringing Oregon's total of measles cases to four.
By the end of 2017, the percentage of children in Ukraine who had been vaccinated had significantly improved, to about 90% but, the World Health Organization says, this now needs to be sustained to protect the population from further outbreaks of measles.
Washington and OR are among 17 states that allow nonmedical exemptions from vaccination requirements for school entry, according to the National Conference of State Legislatures.
The measles outbreak reported in the northwest has made its way to Texas.
The WHO says the 2018 surge in measles cases followed a year when European countries achieved their highest ever estimated coverage for the second dose of the measles vaccination - 90%. Joan Robinson, a pediatric infectious diseases physician and editor of the Paediatrics & Child Health Journal, said that outbreaks often occur in small communities where children aren't vaccinated. Orders of measles vaccines in the county reached 3,150 in January. Now there's concern some of the people exposed to the highly contagious disease may have traveled, putting countless others at risk. There have been calls in recent years for Canada to start a national registry to help officials keep better track of vaccination rates.
The percentage of children receiving the first dose of the vaccine also increased, to 95%.