MINNEAPOLIS — On the first Saturday this May, residents of the Cedar-Riverside neighborhood socialized in the shadows of their towering public housing complexes. Chattering men sat for haircuts while head-scarved women shopped the stalls lining the blue-bricked Riverside Mall. At nearby Currie Park, training-wheeled biker boys chased each other, circling a drained wading pool where girls played a game of tag. Their relatives picnicked in the shade.

Not so visible was the fact that this Somali-American community—Minnesota's largest—is currently experiencing the state's worst measles outbreak in nearly three decades. On Thursday, the count rose to 44 confirmed cases across three counties. Public health officials are now scrambling to keep the disease from reaching pockets of unvaccinated kids in other parts of the state. This means advising accelerated shot schedules to doctors and parents, and considering quarantine orders for anyone who has been exposed. The health officials know that once a measles outbreak gets going, it can be very difficult to contain, even if they expected it.

And they totally expected it. Over the last decade, anti-vaxxers have fortified this corner of Minneapolis into a bastion for pseudo-science. It all began with higher-than-normal rates of severe autism in the Somali community. And when state and university researchers failed to understand why the disorder hit so hard here, families went looking for answers elsewhere: friends, and the all-knowing internet. In came the anti-vax partisans, whose success with these frightened parents has turned the neighborhood into a beachhead for what should be a preventable disease.

Measles kills about 10,000 children a year in Somalia. So when the first wave of refugees from that country's civil war brought their kids to Minneapolis in the 1990s, vaccination rates were high—around 90 percent by 2004. Four years later, Somali parents began noticing a rising number of autistic children in their community. They cried out to city officials, who enlisted researchers from the University of Minnesota, CDC, and NIH to launch an investigation. Those epidemiologists found that autism rates in Minneapolis’s Somali community were higher than the national average. But the rate was identical to autism in Minneapolis's white population.

What was different was that Somali children didn't just get autism, they consistently got the most extreme version of it. By comparison, only about a third of non-Somali kids with autism were also diagnosed with intellectual disabilities—such as delayed speech or difficulty understanding abstract concepts and social rules. For Somali autistics, it was 100 percent.

“In some ways that finding was very consistent with what we were hearing from the community—that autism hits Somali kids much harder,” says the study’s lead author, Amy Hewitt. But her results only told people what they already suspected, not what they were looking for: What was causing the autism.

Not that it would have mattered much if she had. By the time Hewitt’s study was published in 2013, anti-vaccination activists had already claimed Cedar-Riverside. Andrew Wakefield—the study-falsifying founder of the modern anti-vaxx movement—met with upset Somali families three times between 2010 and 2011. And Minneapolis health officials say it’s not hard to draw a line between this targeted misinformation campaign and the current measles outbreak. Kris Ehresmann, director of the health department's Infectious Disease Division, points to the precipitous drop in vaccination rates in recent years: Today, only four out of every 10 Somali kids in the city are protected against the disease. Even as recently as last Sunday, groups like the Vaccine Safety Council for Minnesota organized a public meeting to help Somali families understand their legal rights to refuse the same vaccinations public health officials are anxiously urging them to get.

“The answer used to be education—the more educated you were on the issue the more likely you were to get vaccinated,” says Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research. Those days are over, he says. In no small part thanks to the proliferation of misleading information on the web. “The challenge is for scientists to be humble and acknowledge that in this day and age facts will not win the day,” he says.

Minnesota’s Health Department has been trying to take a page from that playbook. It has changed up its tactics in the past few years—hiring Somali nurses and outreach workers to pave inroads into the community, and working with imams and other leaders to create a network of trusted individuals who can combat internet-fueled fears. And they’ve begun taking up alternative communication strategies. Rather than use bullet-pointed barrages of facts, they illustrate their points with stories about, say, someone whose child came down with measles.

Catherine Mary Healy, the director of the Center for Vaccine Awareness and Research at Texas Children's Hospital, says this is a better strategy for communities that haven’t been exposed to an outbreak of vaccine-preventable diseases. “When they come across misinformation, they interpret it in a different way than you or I might because they’re unable to weight the risk/benefit ratio appropriately,” she says. Healy works with many Latino immigrant groups in Texas, where she says vaccination efforts are highly successful because so many of them have experienced measles firsthand.

This echoes what officials around Minnesota have been clear about from the beginning of the outbreak: This isn’t an immigrant problem or a Somali problem, it’s an unvaccinated problem. But there is reason to be hopeful that evidence-based information can still win the day. Research shows that the most important factor for parents making the decision whether or not to immunize comes down to their doctors' opinion. And the investments Minnesota has made in providing tailored health care services to Somali families, especially those with autistic children, may be beginning to pay off.

The Brian Coyle Community Center, which bustles with basketball-crazed kids, is in the middle of the Cedar-Riverside neighborhood—the outbreak's epicenter. And just a few days ago, the community center's walls had been pasted with flyers promoting the connection between the vaccine and autism. But the Somali staff decided to take them down. On request, the man working the front desk Saturday afternoon (who didn't want to share his name) produces a crumpled advertisement for last weekend's anti-vaxx public meeting. "I don't understand these people," he says, shaking his head. "With my children, if the doctor says to do something, we do it. They know best."