ARI SHAPIRO, HOST:
It's official - the total number of coronavirus infections in the U.S. has now topped 4 million. For weeks now, the case count has largely been driven by spiraling outbreaks across the South and West, but NPR has been talking to forecasters who say mid-Atlantic and Northeastern states could soon be in trouble again. Joining us now is NPR's global health correspondent Nurith Aizenman. Hi, Nurith.
NURITH AIZENMAN, BYLINE: Hi, Ari.
SHAPIRO: Before we get into this warning about what might be coming, update us on where things stand now. The worst outbreaks are still in the South and West, right? How bad is it?
AIZENMAN: Yeah. It's gotten so much worse lately that one of the prominent independent groups tracking this spread, COVIDExitStrategy, has had to create a whole new category, the dark-red zone. They say that means, quote, "uncontrolled spread," defined as at least a 25% rise in new cases over the last two weeks. And right now, 22 states are in that category...
SHAPIRO: Wow.
AIZENMAN: ...Including almost the entire - yeah, it's the entire southern and southwestern half of the U.S. almost. But there are also a sprinkling of states in the northern half of the U.S. - Wisconsin, Idaho. And I've been hearing these growing concerns from forecasters about what could be coming for the mid-Atlantic and Northeast.
SHAPIRO: OK, so that's the bad news. What's the other bad news?
AIZENMAN: (Laughter) Yeah, so this warning about the mid-Atlantic and the Northeast comes from researchers at the PolicyLab at Children's Hospital of Philadelphia. Their model shows an alarming rise in the rate of new infections in those mid-Atlantic and Northeast States. The director David Rubin is an epidemiologist and professor at University of Pennsylvania, and he says it's really noticeable in the I-95 corridor reaching north up from Florida.
DAVID RUBIN: We have launched this epidemic marching right up the East Coast - the beach areas of Virginia, Rehoboth Beach in Delaware. Over the last two weeks, the highest infection rates or rate of growth we've seen in a major city in this country have been in Baltimore, Md., and we are now seeing clear resurgence in the Philadelphia area and its collar counties.
AIZENMAN: And Rubin also points to upticks in the shore regions of New Jersey, even some signs of growing cases in New York City's burrows and similar worries in Boston, Milwaukee, Indianapolis.
SHAPIRO: But I'm thinking about states like New York and New Jersey that have really locked down after what they went through. I mean, they're telling people who come from other states to quarantine. They seem to have been really successful in limiting the spread of this virus. What changed?
AIZENMAN: Yeah, Rubin gives those states and their officials a lot of credit. He says in contrast to much of the South, they kept their social distancing in place long enough to really push down their caseloads. Then they were careful about not opening up super-fast. But the trouble is they don't exist in a vacuum. In a country like the U.S. where there's lots of travel, you're only as strong as your weakest link. And it's telling that a lot of these places in the Northeast that seem to be seeing these incipient upticks are associated with summer travel. Rubin says that makes it hard to respond there.
RUBIN: I've privately heard officials express some level of resignation that we could even go into sheltering in place. But if families are traveling outside the area and coming back, as soon as we lift those restrictions the transmission will return.
AIZENMAN: Basically, he says, we need a nationwide strategy to get this under control everywhere and keep it that way. Otherwise you're going to keep seeing outbreaks in one part of the country, ceding outbreaks in others.
SHAPIRO: So is there any hope that these two states can avoid seeing a return to the bad, old days of a couple of months ago?
AIZENMAN: Well, look; while this model does coincide with some other models on New York, Philadelphia and Rehoboth, Del., in particular, this one is more pessimistic. But more importantly, Rubin says there is still time to turn this around, just that the time to act is now.
SHAPIRO: NPR's Nurith Aizenman, thank you very much.
AIZENMAN: You're welcome. Transcript provided by NPR, Copyright NPR.