Good news of fewer cases may pose holiday risk
For many Wisconsin residents, there’s no doubting the threat COVID-19 poses these holidays.
Some will spend them grieving a life lost too soon. Others are sick, or toiling through double shifts in the ICU, or waiting by the phone for updates about a hospitalized loved one.
But disease experts worry there are many who will see encouraging news about declining cases and incoming vaccines and underestimate the risk of gathering with people from outside their home. With them, the experts plead: ’Tis not the season, yet.
While the state’s seven-day average of newly confirmed cases has rapidly fallen from its peak of nearly 6,600 on Nov. 18 to under 2,700 on Tuesday, the seven-day average of new deaths has actually increased, to 60 per day. That’s worse than the state’s leading killers, heart disease (32 per day, at 2017 rates) and cancer (31 per day), and six times the 10 state residents who die each day of accidental causes.
And though 2,800 cases per day is lower than 6,600, it’s astronomical compared to spring, late July and early fall, when then-record cases prompted state mandates to control the virus and school closures. What’s more, those infected this fall have been more likely to be older than 60, and therefore more likely to be hospitalized and die.
Said University of Wisconsin-Madison epidemiologist Malia Jones: “At this moment, right as a vaccine is about to become available to those people who are at the highest risk of dying of COVID, this is not the right moment to let down our guard.”
After perplexing downturn, experts fear predictable outcome
Whatever caused new cases to peak and then plummet here, it’s not just a Wisconsin thing. It happened throughout the Midwest.
According to covidexitstrategy.org on Tuesday afternoon, COVID-19 cases had increased 6% throughout the U.S. over the past two weeks but were down 51% in Minnesota, 35% in Michigan, 32% in Iowa, 26% in Illinois, 25% in Wisconsin and 19% in Indiana.
Plains states that surged at the same time as Wisconsin are way down, too. New cases in North Dakota have fallen 51% and South Dakota 39%.
One possible explanation: So many people in these states have been infected — and thus immunized — that the coronavirus is having a tougher time finding new hosts.
Modelers continue to debate how many people need to be infected before a population develops a strong community resistance to COVID-19. Some have pegged that number as high as 70%, while others have it as low as 20%.
Wisconsin ranks third among states (behind the Dakotas) in infections per capita since the start of the pandemic, according to the Centers for Disease Control and Prevention, with about 8% of its residents having tested positive by molecular test.
That’s nowhere near 20%. But many residents have had asymptomatic cases and never known it, or they felt symptoms and decided not to get tested. Others have received positive antigen (or “rapid”) tests, which aren’t included in the confirmed case numbers published by the state’s Department of Health Services.
In early December, Fox Cities’ ThedaCare hospital system estimated that, with those unseen cases included, 23% of people in its region had been infected. That’s near the levels observed by antibody surveys in New York City, where more than a thousand people died each day this spring but virus activity has been much more subdued since.
Populations can develop a resistance to COVID-19 at such low levels by “ex
hausting the susceptibles,” said UW-Madison and former CDC epidemiologist Patrick Remington. When a wave of COVID-19 hits, people who take more risks are more likely to become infected and spread the virus to others. Once COVID-19 burns through them, it encounters a population increasingly made up of people who practice social distancing, wear masks and stay home when ill.
“I think there is evidence of that happening,” said Remington, who said about 15% to 20% of Wisconsin residents have likely been infected — in line with the most recent estimate of 16% by the University of Washington’s Institute for Health Metrics and Evaluation, a leading model.
But Remington and others who spoke to the USA TODAY NETWORK-Wisconsin don’t think that’s the whole story behind the decline in cases, or that the virus can now be expected to peter out on its own.
Ali Mokdad, a professor of health metrics sciences at the University of Washington’s Institute for Health Metrics and Evaluation, said our collective psychology is likely what most reined in spread over the past month: As cases shot up in fall, so too did the number of people who knew somebody personally affected by bad outcomes of COVID-19, or saw headlines about overrun hospitals, or felt they needed to close their school or business. It became harder to deny the danger and easier to comply with guidelines.
There’s a flip side to that, though.
When things begin to improve after a dramatic surge like Wisconsin’s, Mokdad said, case levels that once seemed high no longer carry the same sobering weight. Within the 84% of Wisconsinites that IHME’s model assumes are still uninfected, many will relax and become more susceptible again as case levels lower.
Remington said he can vividly recall looking at the data May 29, when there were 733 cases, and thinking to himself, “We may have 1,000 cases someday.” Now that there hasn’t been a day with fewer than 1,000 cases since September, that level of spread is less likely to make people think twice before leaving their home, he said.
Mokdad said there are early indications that people in Wisconsin again are being lulled into a false sense of security.
Cellphone mobility data earlier this month indicated Wisconsinites were on the move about 23% less than they were before COVID-19, compared with 27% below that baseline in late November and 55% below the pre-pandemic baseline back on April 1. The percentage of Wisconsin residents who say they always wear a mask in public had started trending down slightly, too, from 69% in late November to 68% as of Dec. 15.
If there are those in Wisconsin whose healthy fear of the virus is starting to wane, it’s coming at a less than ideal moment.
Holidays may pose a particular threat to those over 60
The CDC and DHS have both issued guidelines for the holidays that will be familiar to anyone who was paying attention before Thanksgiving.
Boiled down: If possible, celebrate with the people who live with you — excluding even college students on school break, unless they’ve quarantined for 10 days. Limit travel. And if you do see people who don’t live with you, wear a mask and remain socially distanced.
Remington said he looks forward to seeing his children and grandchildren, but “the only way we’re going to do it is if it’s safe and if we’re outdoors, six feet apart.” Jones said she hopes planned gatherings with older relatives will be postponed until Easter, by which time those relatives are expected to have gotten the vaccine.
It’s impossible to know whether people will take such advice to heart as much as they did before Thanksgiving, especially since a post-Thanksgiving surge hasn’t materialized, and news around COVID-19 has been much more positive of late.
Jones and Remington believe the stern messaging around Thanksgiving gatherings is at least partly why cases decreased — and it’s “the tragedy of good prevention,” Jones said, that it might work against us now.
“I am really concerned that we could see even more loss of faith in public health recommendations because this thing that we were trying to prevent was actually prevented,” she said.
And while new cases have fallen in every age group, they have fallen at a slightly slower rate in the four most vulnerable groups: those in their 60s, 70s, 80s and 90s.
Mokdad said age is the best predictor of COVID-19 outcomes — better, even, than underlying conditions (which may have led those over 75 to be moved ahead of other at-risk groups in line for the vaccine).
In Wisconsin, those over 60 have been hospitalized in about 14% of known cases, or seven times as often as those younger than 60. People over 60 account for 68% of all cases involving intensive care, and 92% of the state’s deaths.
Wisconsin residents in their 80s have been more than three times as likely to be hospitalized (27%) as those in their 60s, and 10 times as likely to die (11%, compared with 1.1%). But those in their 60s are 10 times more likely to die than those in their 40s.
To illustrate the dramatic effects of age and the importance of keeping older people safe these holidays, USA TODAY NETWORK-Wisconsin used a model built by Mahima Bhattar, an intern for Jones at UWMadison’s Applied Population Lab, that converts new cases into likely hospitalizations, intensive care admissions and deaths, and then charts those outcomes on future dates.
If cases hold steady at current levels for the next 30 days and the age distribution doesn’t change, hospitalizations would decrease by 236 to 1,032. Forty-nine fewer people would be in the ICU by then, and 811 would die.
In a scenario where cases decrease 20% over the next 30 days and the people infected trend considerably younger again, there would be 143 fewer deaths, 346 fewer peak hospitalizations and 51 fewer peak ICU stays.
And in a scenario where cases increased 20% and trended older, there would be 163 more deaths, 447 more peak hospitalizations and 64 more people in the state’s ICUs.
Barring unforeseen problems with the rollout , vaccines will start to change things for the better early in 2021, with the elderly among the first able to be vaccinated.
But that will still “kind of be a little bit late,” Mokdad said. The vaccines come in two doses, spaced three weeks apart, and the virus is still rampant as officials race to inoculate as many people, as fast as possible.
The IHME model, as of its Dec. 17 update, projects Wisconsin will see nearly 4,000 more deaths by April 1 — or possibly as few as 3,000 with an accelerated vaccine rollout and universal mask use.
To individuals who are still waiting their turn for the vaccine, Remington urged patience and sustained or renewed caution.
“This is kind of the fourth quarter of a football game where you’re up by a touchdown,” he said. “You don’t want to make a mistake here and lose the game.”
“I am really concerned that we could see even more loss of faith in public health recommendations because this thing that we were trying to prevent was actually prevented.”
Malia Jones University of Wisconsin-Madison epidemiologist
“This is kind of the fourth quarter of a football game where you’re up by a touchdown. You don’t want to make a mistake here and lose the game.”
Patrick Remington UW-Madison and former CDC epidemiologist