Measles is spreading among conservative, insular communities in the US.
The outbreak in New York exists primarily among Orthodox Jewish people who object to vaccinations against the disease on religious grounds.
But in Washington, the strain of the measles sweeping the state - and especially Clark County - came from Ukraine.
And it is now thought to be spreading largely among the tight-knit community of Eastern European immigrants there, who trust information they get from one another more than they do information from doctors.
The information that makes its way through these social networks often involves misunderstandings and misinformation, such as the idea that fetuses have to be aborted for a dose of the shot to be made, Vox reported.
Measles is a highly-contagious virus. There are 72 cases of the disease in a single Washington state county where two percent of the population is Russian-speaking and disproportionately struck by the outbreak, as myths and misinformation spread in their insular communities (file)
So far, there have been 72 cases of measles diagnosed in Washington - and all but one are in Clark County.
The state's Department of Health (DOH) has confirmed that the primary strain spreading in the area is the same one decimating Ukraine, so it was likely brought to Washington by a traveler.
Eastern Europeans account for about 8.4 of the state's population, and Clark County is known for its large population of immigrants from the region and their descendants.
Nearly two percent of the population of Clark County spoke Russian, according to the 2000 census.
Back in 2012, vaccination among Eastern Europeans was already a significant concern to the Washington DOH, as evidenced by the fact that it undertook a special investigation and report on the attitudes and behaviors of these communities toward shots.
The report was commissioned because Russian-speaking communities had the lowest vaccination rates in the state - and had since 2008.
By conducting interview with 'key informants' - representatives in touch with both the community and the public health issues - the report uncovered a number of barriers that have kept vaccination rates low among these communities.
The health officials found that most Russian-speakers' beliefs and attitudes toward shots were primarily influenced by those in their close social circles, including family, friends and religious communities, as well as Russian-language media.
One woman, Valerie Kobylnik, who was born in Kyrgyzstan and immigrated to Washington in 1991, told Vox she believed vaccines would hurt her children so, for years, she did not get them immunized, based on what she'd read and watched.
Somehow, many other mothers in her close Russian-speaking community began searching her out and asking her about her decision - coming to Valerie, despite the fact that she had no medical expertise.
The 2012 report suggests that
