Those keeping an eye on the US's coronavirus case and death curves will notice a seemingly hopeful trend: New daily cases are skyrocketing, but daily deaths have so far remained relatively flat during this second surge.

Indeed, projections from the University of Washington's Institute for Health Metrics and Evaluation (IHME) suggest that this new peak is not expected to be as deadly as the one in April.

That's primarily because increased testing means more mild cases are being confirmed, and young people represent a larger share of coronavirus cases than they did at the start of the outbreak. (We know now that COVID-19 is far less fatal in younger people.)

In Florida, the median age of coronavirus cases has dropped to 35, compared 65 in March. Cases among people under 40 are also rising in Arizona, California, Minnesota, Ohio, South Carolina, and Texas.

But even if higher case counts don't bring a proportional surge in deaths, there is still reason for alarm. The IHME model projects that the US will see nearly 50,000 new coronavirus deaths from July to October 1. That's close to the number of US combat deaths recorded during World War I.

Put another way, the model expects the US to see 500 or more people die of COVID-19 every day for the next three months, on average. The projection accounts for seasonality, the amount of testing being done, and how often people are interacting with others outside their household.

Currently, more than 128,000 people have been killed by COVID-19 in the US, so the additional projected deaths represent a nearly 40 percent increase. These deaths are expected to arrive as other countries' daily cases and deaths continue to drop precipitously.

And if that wasn't concerning enough, there's still a strong possibility that coronavirus deaths will rise in the near future.

"No one wants to say too early that deaths are not rising. That would really be a mistake," Howard Koh, a professor at the Harvard TH Chan School of Public Health, told Business Insider.

"If somebody is infected and then has the risk of getting sick and being hospitalized and dying – that whole trajectory takes a number of weeks, at least, maybe up to a month or more."

Hospitalizations are on the rise, too

Over the last week, the US has recorded its highest numbers of coronavirus cases to date: around 47,000 daily cases, on average. Thursday marked the peak of the outbreak so far, with more than 55,000 cases. New cases are now rising in the majority of states.

Nationwide deaths, meanwhile, have declined considerably since their peak in April. Over the last week, the US has seen around 560 daily deaths, on average, compared to more than 2,7000 deaths on April 21, the deadliest day of the outbreak.

President Donald Trump has attributed the nation's rising cases to an increase in testing. The US is now testing 59 out of every 100,000 people – a lower rate per-capita than Russia, Iceland, and Australia, but a higher rate per capita than France and the UK.

But the nationwide percentage of COVID-19 tests coming back positive is rising – a sign that increased testing isn't the primary reason for the growth in new cases. Instead, experts suggest that the surge reflects increased transmission, since people have started interacting more without sufficient distancing or mask-wearing.

"We're all speculating that after Memorial Day, it was really the younger people who perhaps reengaged with society too soon and without the proper precautions," Koh said.

Epidemiologists usually predict a two- to three-week lag between when new cases and new deaths are reported. Based on that estimate, the US should already see an uptick in coronavirus deaths. But Koh said a surge is still possible in the coming weeks.

"In places where cases are rising, hospitalizations are increasing, too," Koh said. "We will inevitably see deaths coming in such situations, unfortunately."

Indeed, the daily death total has started to rise in Arizona and Texas. On Tuesday, Robert Redfield, director of the US Centres for Disease Control and Prevention, said hospitalizations were rising in 12 states as well.

"We're starting to see that uptick in deaths coming now," Dr. Theo Vos, who works on the IHME model, told Business Insider.

'All the trends are going the wrong way'

The IHME model accounts for two scenarios: Either social-distancing mandates continue to be lifted and mask use stays the same, or countries pull the emergency break by reinstating mandates if deaths climb too high.

Either way, nationwide deaths are projected to stay relatively flat – but at a number far too high for comfort.

"If you look at other countries, they are down on the other side of the curve. Their cases have dropped dramatically. Their deaths have dropped dramatically," Koh said. "We're nowhere near that right now. All the trends are going the wrong way."

The US is currently seeing around 39 coronavirus deaths for every 100,000 people. Of the 20 countries currently most affected by COVID-19, only the UK has a higher death rate per capita right now: around 66 coronavirus deaths for every 100,000 people. If US deaths continue at the current rate, however, the nation could climb to the top of that ranking.

The IHME predicts that total US deaths could top 175,000 by October. And that doesn't include deaths through the entire fall season, which many experts think will be the worst phase of the outbreak.

"Our model strongly suggests that there's quite a seasonable component to this disease," Vos said. "Come the fall, we expect the pressure on transmission to go up."

Deaths could surge in the fall, but masks can help

Experts worry that a surge of coronavirus cases on top of regular flu outbreaks this fall could place additional strain on hospital capacity, leading to many more deaths that could have been prevented.

"I see too many patients die too early of preventable causes and that's an absolute tragedy," Koh said. "What we can accomplish in the long run depends so much on whether we can maximise the power of prevention based on the tools we have: face masks, social distancing, and hygiene."

The IHME model predicts that about one-third of transmission – or 24,000 deaths – could be prevented if 95 percent of the US population wears masks in public from July to October.

"It is such a cheap and relatively easy option with quite a potential to make a substantial dent in this epidemic," Vos said.

Koh said a national face mask policy is perhaps the most critical step to preventing future coronavirus deaths. At least 21 states have instituted a statewide mask mandate so far.

Texas became the most recent addition to that list on Friday, when Gov. Greg Abbott issued an executive order requiring masks in counties with 20 or more active COVID-19 cases. Failure to comply with the mandate could result in a fine of up to US$250.

But the specifics of mask requirements differ state to state, and some cities and counties have implemented their own policies.

"We have 50 states going in 50 different directions," Koh said. "This all leads to tremendous confusion among the public about what's the public-health standard."

Under a universal mask mandate, US coronavirus deaths could drop to less than 100 per day by September, according to the IHME model. Koh said it's important for individuals to realise that these aren't just numbers – they're real people's lives.

"When prevention works, absolutely nothing happens. All you have is the miracle of a perfectly normal, healthy day," he said. "Maybe because I'm a physician I've seen that gift forfeited so many times. We need to convey the fragility of our good health right now."

This article was originally published by Business Insider.

More from Business Insider: