Transcript for 21 states and Puerto Rico see rise in COVID-19 cases
We're going to turn next to real concern in this country tonight, with what authorities are now seeing involving the coronavirus. 21 states with cases on the rise today, and Arizona tonight, for example, health department officials there are now telling hospitals to activate their emergency plans. And tonight here, an important clarification after the world health organization confused so many all over the world, so, can you spread the virus if you're asymptomatic? Here's Matt Gutman on that tonight. Reporter: Tonight, Arizona's health department urging hospitals to activate their emergency plans. More than 5,000 new cases since and now hospitals saying they're maxing out on icu beds. We need to really be socially response when we go outside, socially distance. You know, I think there's evidence that we're not doing that. Reporter: 21 states and Puerto Rico registering a rise in covid. And 14 states, including Arizona, have seen their highest seven-day average growth since the pandemic began. The governor here lifting that stay at home order on may 15th. People gathering in large groups again at bars and restaurants. You know, right now we're fine. But if we continue at -- at a rate like this, we're facing a significant chance that we're going to have to shut down the state again. Reporter: FEMA saying community transmission is the highest driver of growth in nearly two-thirds of the hot spots in 31 states. Scott Felix is a 25-year-old who says he got sick after camping during memorial day. He spiked a 104 fever and tested positive for covid. A lot of people that I talked to and said that they felt like they may have already had the coronavirus and it would be safe to go outside. I would say don't assume that. Reporter: And David, the world health organization is now walking back that surprising claim, saying that asymptomatic people can and do spread the virus, but they admit they don't know exactly how that happens. David? Very important, again, asymptomatic people can still spread the virus. And Matt, we thank you for that.
This transcript has been automatically generated and may not be 100% accurate.