A MARTINEZ, HOST:
Public health experts are growing increasingly concerned that new COVID-19 hot spots may be emerging around the country, and Michigan tops the list. NPR health correspondent Rob Stein has more.
ROB STEIN, BYLINE: Like most of the country, infections had plummeted in Michigan after the terrible winter surge. But in the last few weeks, that looks like it's turned around. Infections have jumped back up, and so has the number of people getting so sick they're ending up in the hospital. Emily Martin is an epidemiologist at the University of Michigan.
EMILY MARTIN: It's definitely concerning. We're definitely paying serious attention to it.
STEIN: Now, it's not clear why this is happening. Part of it could be that as more people are getting vaccinated, the state has started loosening up, letting more people gather in restaurants and bars. More students have been getting together after school.
MARTIN: And so there's this feeling like it's time to try to drive towards normal. But we don't have the level of protection in the population that we need to really be doing that fully yet.
STEIN: And some fear Michigan could be a kind of canary in the coal mine for what everyone's been worrying about - that the country could start losing the race with the variants, that the more contagious variants would start spreading faster than the country is vaccinating people, triggering yet another surge. Nicholas Reich is at the University of Massachusetts at Amherst.
NICHOLAS REICH: Michigan is the first state in the U.S. where we're really seeing this turn around, what appear to be variants causing increase in cases. I'm anticipating that we will see multiple states have similar patterns to what we're seeing in Michigan now that will get us back up to some sort of a mini surge.
STEIN: In fact, Michigan is already far from alone. It looks like cases have started creeping back up in some other places, too, in the Midwest, the Northeast and the mid-Atlantic and stalled in others. Ali Mokdad at the University of Washington says fewer and fewer people are still wearing their masks as more and more states are dropping their mask mandates.
ALI MOKDAD: We need to be very careful, and states should be extremely cautious in opening up. We should consider seriously hitting the brakes now before it's too late.
STEIN: He's worried what might happen when all those young, unvaccinated people on spring break in places like Texas and Florida head home, possibly carrying the more contagious variants with them.
Rob Stein, NPR News. Transcript provided by NPR, Copyright NPR.