A snapshot of coronavirus in the U.S.: A high plateau of new cases portends more spread

For all the talk of a second wave of coronavirus cases hitting the United States this fall, one consideration is often lost: The country is still in the throes of the first wave of this pandemic.

Even as roughly half of states start to peek out from under their lockdowns, the United States confirmed more than 25,000 new Covid-19 infections nearly every day in April, a clip that does not seem to be dropping in May, according to STAT’s Covid-19 Tracker. More than 1,000 people have died each day since April 2. On some days, including both Tuesday and Wednesday this week, the toll topped 2,000.

So if the curve has been flattened somewhat, it is not coming down.

Some states and cities are reporting hints of progress. In Massachusetts, hospitalizations have dropped, even if the number of deaths has not yet buckled. Newly confirmed cases are down in New York City. The Bay Area’s early shelter-in-place appears to have staved off the worst impacts of the crisis for now, and ensuing policies elsewhere helped minimize the pain.

But cases are increasing in other areas, according to the tracker, a partnership between STAT and Applied XL, a Newlab Venture Studio company, that compiles data from 15 sources. Texas has reported more new cases in each of the past few days than it typically did in mid-April. Cases are accelerating in Kansas. Outbreaks continue to build in prisons and meat processing plants.

There have been more than 1.2 million confirmed Covid-19 infections in the United States; experts say the true number could be 10 times that. But even if those people are immune from a second infection for some amount of time — which scientists still need to confirm — that still leaves the vast majority of Americans susceptible to contracting the virus.

The plateau in case counts at such a high level nationally also means there is still lots of virus lurking around. Infections have remained stubbornly elevated even as, in most places, people who could stay home and avoid contact with others generally have.

Now we will get a glimpse of what happens as people start to move around more.

About 30 states have started to ease the lockdown restrictions imposed to suffocate the spread of the virus, or will soon. What’s allowed and when varies by state, but most governors have outlined gradual approaches, with limited capacities at restaurants, malls, and theaters. They have the backing of President Trump, even though many don’t meet the White House’s recommended milestones for when it would be safe to emerge from stay-at-home policies, one of which was a decline in cases for 14 days.

It’s an attempt by governors to balance out the economic, social, and psychological impact of shutdowns, which have also caused lasting effects on people’s health and well-being. But it’s also an experiment that will examine whether phased reopenings can occur without setting off an explosion in cases — and overwhelming health care systems.

“I’m somewhat sympathetic, as I think everyone is, to the impulse to try to open up,” Marc Lipsitch, an epidemiologist at Harvard’s T.H. Chan School of Public Health, said last week. But, he added, “I don’t think at this point that it’s good public health advice to reopen in most parts of the United States, because cases numbers are high, and testing is poor. And that’s where we were a long time ago.”

Reopening at a starting point of such a high number of infections not only increases the likelihood of wider spread (an initial 1,000 cases can balloon into exponential growth much faster than an initial 10 cases), but it also makes it more difficult for public health agencies to track all cases and trace their contacts. Experts say these are crucial steps if infections are going to be driven down and a resurgence of transmission is going to be held off and minimized.

And although the testing situation has improved in the country, experts say the number of tests being run every day remains below where it needs to be to effectively hunt the virus and snuff out transmission chains.

“One thing that has been at least an idea I’ve heard expressed many times is, ‘Well we’ve reached a peak and therefore it’s time to reopen,’” Lipsitch said. “But viruses don’t know where they were in the past, they only know where they are in the present. And what I mean by that is if we had X number of cases per day at the start of imposing restrictions, and now we have a lot more than X cases per day, as seems to be the case in most places, but we’ve slowed down the increase, we’re in a worse position now than we were then.”

With more virus spreading now than when lockdown restrictions were first imposed, Lipsitch continued, “there’s not much logic in the idea that slowing down the growth is good enough and now we can reopen. The logic is in reopening when the number of cases has come down sufficiently that we can expect that the growth that will result when we reopen is manageable and will not overwhelm our health care system. If we were worried about it being overwhelmed a month ago or a month and half ago when the restrictions started, and there are more cases per day now, then we should be more worried, not less.”

As states pursue different reopening timelines, the scope of their local outbreaks will continue to diverge, even as an outbreak in one community can spill over to others.

The impact of reopening in a given state also won’t be clear for some time, even if transmission of the virus takes off. Cases can build silently; people can spread the disease before they show symptoms, and that can take a few days. Some portion of people do not feel that sick or show symptoms at all. So if a wave of people needing care suddenly floods into hospitals, that’s a reflection of transmission that occurred some two weeks prior — spread that could have only grown in the interim.

An unknown in what will happen as states lift restrictions is how residents will respond. Many people feel it’s not safe to go eat at a restaurant even if they now can. If people continue to wash their hands regularly and stay home if they are not feeling well, those individual steps can accrue into a major influence.

But that might not be enough. A model released Thursday by Columbia University researchers, which analyzed loosening stay-at-home orders, forecast a resurgence of cases by the end of the month.