In a Friday phone call about new guidelines around school reopening, Center for Disease Control Director Dr. Robert Redfield told reporters that “hot spots” of COVID infection where schools should stay closed should be defined as communities where “the percent positivity rate within the community is greater than 5%.”

Over the last seven days of available data, Mecklenburg County has averaged 10.97%.

Redfield’s comments came a day after the CDC released updated guidelines for schools that are trying to figure out how to safely educate K-12 children in the midst of the COVID pandemic.

The CDC guidelines say, “It is important to consider community transmission risk as schools reopen. Evidence from schools internationally suggests that school re-openings are safe in communities with low SARS-CoV-2 transmission rates.”

President Trump conceded shortly before the guidelines were released that “cities or states that are current hot spots” may need to stay closed. It was a major about face for a man who just two weeks ago was threatening to withhold federal funding from schools that don’t reopen.

In the Friday phone call with reporters, Director Redfield was asked what metric was used to define a “hot spot”:

You mentioned a few times that in hot spots, that there may be, you may need to keep schools closed for a time. My question is how much of the country right now would you consider to be a hot spot? Because a lot of times we look at this and we see a large swatch of the country across the Southeast with hot spots. Are those considered hot spots?

Here’s how Redfield responded:

When you look at the hot spots, I think most of us right now are looking where the percent positivity rate within the community is greater than 5%. And a lot of times the maps you see aren’t granular area to let you see rather than light up a whole state, it may be really several counties that meet that criteria. And it is quite dynamic. It is changing. You know, a number of counties now are substantially improving. There are several counties getting where there is an increase in percent positive. That’s why it’s so important for the local education boards and local health departments to look exactly at the data in their environment at this moment in time.

The 5% positive metric mentioned by Dr. Redfield is the same benchmark being used by Governor Andrew Cuomo in New York, where schools are permitted to reopen when regional infection rates are 5% or lower over a 14 day average.

Yesterday New York registered its lowest number of COVID hospitalizations since mid March.