Nearly half of US states are reporting a rise in new coronavirus cases

People get tested for COVID-19 at a drive through testing site hosted by the Puente Movement migrant justice organization Saturday, June 20, 2020, in Phoenix. Latinos are especially vulnerable to infection because they tend to live in tight quarters with multiple family members and have jobs that expose them to others. They also have a greater incidence of health conditions like diabetes that put them at higher risk for contracting COVID-19. (AP Photo/Matt York)
People get tested for COVID-19 at a drive through testing site hosted by the Puente Movement migrant justice organization Saturday, June 20, 2020, in Phoenix. Latinos are especially vulnerable to infection because they tend to live in tight quarters with multiple family members and have jobs that expose them to others. They also have a greater incidence of health conditions like diabetes that put them at higher risk for contracting COVID-19. (AP Photo/Matt York) (Copyright 2020 The Associated Press. All rights reserved)

CNN –  The first wave of coronavirus in the US isn't over.

Nearly half of states are reporting a rise in new cases and some continue to break records in their daily reported cases. In the South, officials say more young people are testing positive. And across the US, experts continue to repeat warnings highlighting the need for social distancing and face covers.

And while some point to the rise in numbers as a result of more testing, health officials say more tests are only partly to blame.

"More testing does in fact turn out more cases. However ... if widespread testing was the entire reason for the rise in cases, you'd expect to see the proportion of positive tests go down or at the very least remain steady. We're not seeing that," says Dr. Shoshana Ungerleider, a specialist in internal medicine at the California Pacific Medical Center.

"This has nothing to do with more testing and everything to do with behavior," she said. "We need to talk to people about following the guidelines, wearing masks, avoiding crowds, staying home if possible and washing their hands."

But parts of the country remain divided on wearing face masks in public, and more officials have had to consider making face covers in public a requirement.

As those discussions take place, the US Centers for Disease Control and Prevention says it will soon make an updated recommendation on the public health benefits on masks, a senior agency official told CNN.

The CDC has so far been conducting a scientific review on the topic, and a senior official with knowledge of the review says researchers are studying whether masks are not only "good for source control -- and keeping you from giving it to others -- but we're also seeing if masks are going to protect you from getting (Covid-19) yourself."