Preliminary data seems to show that childcare centers aren’t a source of outbreaks.

As COVID-19 cases continue to climb in many states, moms and dads are understandably nervous about sending their kids to daycare or summer camp. Essential workers, of course, have had no choice.

Now, early data from the camps and daycares that have remained open during the pandemic provide some reassurance for working parents who desperately need a few hours of uninterrupted work: Of 545 childcare centers that stayed open, only .16 percent had students with a confirmed case of COVID-19. That’s 22 children out of 13,493.

Those numbers, as of Thursday afternoon, come from an unscientific survey of childcare centers kept by Brown University economist Emily Oster, who started maintaining a tally after she went looking for information on COVID-19 cases at daycares, and couldn’t find it anywhere.

She points out that her data is crowdsourced and not random, and it doesn’t involve actual COVID-19 testing. But two large childcare providers who have been caring for, collectively, tens of thousands of children since March, the YMCA of the USA and New York City’s Department of Education, told NPR that they have no reports of coronavirus clusters or outbreaks.

Taken together, this anecdotal evidence seems to confirm what other countries are also reporting—that childcare and elementary-age school environments don’t seem to be a big source of spread for the deadly virus. Both Denmark and Finland, which reopened school settings for young children weeks ago, report no increase in COVID-19 cases as a result.

Scientists have known for some time that the disease is far less severe in children, but they are unsure how likely kids are to contract it or pass it along. Even if children don’t spread it to one another often, teachers and daycare workers might be vulnerable to catching COVID-19 from their charges. Here, Oster’s data also provides some optimism: Of the centers open the whole time, only 43 staffers out of 4,967, or .87 percent, came down with a confirmed case.

Those that remained open took many precautions for the safety of students and staff, including mandatory mask wearing, staggered drop-offs and frequent hand-washing, just to name a few.

Oster hopes there will be an official, systematic effort to gather more data on COVID-19 cases at childcare centers. “For sure we will see some cases, but the question is really whether childcare settings are a source of spread,” she says. “At least in the data we have so far, there are a number of situations with one or two isolated cases.”

That information could be key as educators and officials debate whether to reopen schools in the fall, Oster says. “My sense is that most school systems will feel a lot of pressure to open—as they should—due to the learning losses associated with having kids out of school. We need to figure out how we can open safely.”