Health officials are now being forced to state something so painfully obvious as to be almost unthinkable: Parents, please don’t purposely infect your children with the measles.

According to several reports, parents who are steadfastly against vaccinations are actively attempting to get their child sick in order to “get it over with.” It reinforces the idea that many anti-vaxxers believe the measles is harmless and that children exposed to it become tougher having gotten it.

According to the California focused health blog State of Health, some within the anti-vaccination community are organizing “measles parties” – think “playdate” but with every child being exposed to a dangerous, preventable disease:

Julie Schiffman is a mother of two in Marin County. The choice to not vaccinate her kids, now 6 and 8, was a long and difficult one, she said. But deciding whether to intentionally expose them to measles was easy. “I would never do that to my kid,” she said. She was approached recently by a friend who knew her kids were unvaccinated. The friend offered to help set up a play date with another child who was sick. “She said, ‘I know someone who has the measles, would you like to be connected with them?’” Schiffman said.

This intentional infection could have a devastating impact on the spread of the disease that was, until recently, nearly eradicated from America. California, where a recent measles outbreak began at a Disney theme park, has been hit particularly hard with new cases, in part because of the state’s thriving anti-vaxxer community, which in some areas is so large that half of local school children are unvaccinated.

As State of Health notes, measles and chicken pox parties have their roots in pre-vaccination eras, when parents (and doctors) would want kids exposed to the diseases. The idea had less to do with “toughing up” kids and more with the fact that there was no cure for the illnesses and in adults both could be much more severe. Doctors advised parents to infect their children while they were young, because they had to choose between a bad option and a potentially worse one.

Today, the situation is much different. A measles vaccine has been around since the 1960s and a chicken pox one since 1995. Kids exposed to the measles today are being put at risk needlessly.

“It unnecessarily places the exposed children at potentially grave risk and could contribute to further spread of the outbreak,” the California Department of Public Health said in an email, adding that it “strongly recommends against the intentional exposure of children to measles.”

In recent months, faced with growing public anger over their decision, parents who choose not to vaccinate are entrenching themselves behind several dangerous ideas. First, despite all possible scientific evidence, they insist vaccines are dangerous for children. But if that doesn’t shut people up, the movement has started to toy with the baffling idea that the diseases being prevented by MMR shots aren’t even harmful and therefore preventing it is unnecessary. The effort has led to some bizarre propaganda, including a children’s book glorifying a child who had the good fortune of contracting the measles.

Now, it seems, they are so convinced that they are willing to put their child’s life on the line to prove their point.

Feature image courtesy Manu/Flickr