Bracing for mix of flu, COVID19
Disease doublepunch could overwhelm area hospitals
The Bay Area blunted the impact of its first brush with the coronavirus, but infectious disease experts warn there are more outbreaks to come once the region eases shelterinplace restrictions, and one looming event is of particular concern: the flu season.
No one yet knows what to expect in the fall and winter, when the coronavirus may commingle with seasonal influenza. But even as public health officials battle the current COVID19 outbreak, they’re bracing for a resurgence of cases and a potentially much deadlier situation in a few months.
“This was a really good practice run for what may be a worse winter,” said Dr. David Relman, an infectious disease expert at Stanford. “We need to
be thinking really carefully now about the strategies we can use to address both things at the same time.”
Reopening the economy leaves the region vulnerable to an increase in new cases, even with some social distancing measures still in place. If testing continues to fall short, or contact tracing programs aren’t robust enough, those small upticks could explode into new outbreaks. And if that happens in the middle of the flu season it could be disastrous, Relman and others said.
Scientists nationwide have developed models to forecast how the pandemic may play out over the coming months or even years before a vaccine comes along. Most models predict repeated swells, perhaps some large enough to send communities back into sheltering in place, followed by periods of relative quiet.
Since the coronavirus hasn’t been around for a year, it’s impossible to say whether it will be seasonal like influenza and many other respiratory viruses. Still, most of the models forecast scenarios where COVID19 surges alongside seasonal flu. And health care systems need to be prepared regardless, public health experts said.
“We haven’t known this virus for decades or generations or even millennia the way we have influenza. We really don’t know how this virus is going to behave,” said Dr. Anne Schuchat, principal deputy director of the Centers for Disease Control and Prevention, in an online interview with JAMA this month.
“What we do this summer is going to be critical,” she said. “The more we intensify testing and expand public health capacity and assure that our hospital capacity is adequate, the better we’ll be in the fall. We need to take advantage of the lower levels of transmission we’re starting to see now to really up our game.”
Previous pandemics, including the 2009 H1N1 influenza pandemic, offer a big clue as to what to expect. The H1N1 outbreak began in the spring with clusters of cases worldwide, then dropped a bit in the summer before surging to pandemic levels in the fall, a month or two ahead of the typical flu season.
That surge was timed in large part to students returning to school, allowing the virus to freely circulate. But H1N1, like many influenza strains, also is inherently seasonal.
With the coronavirus, most public health experts expect an uptick in cases as regions lift stayhome restrictions over the coming weeks. Whether they’re able to keep those clusters contained will depend on local resources and other factors, including how well people continue to follow social distancing practices. Based on what happened with H1N1, schools will likely be a big target of policies to prevent transmission, assuming they reopen this summer or fall.
Even with the best efforts, though, communities will almost certainly see periodic increases in new cases, and the potential for one of those upswings to occur during the flu season is especially problematic.
On an individual level, infectious disease experts worry that patients could be infected with both the coronavirus and influenza at the same time. A handful of studies, including one at Stanford, have shown that’s possible, but it’s not yet known how common coinfections are and if they cause much more severe illness.
A combined COVID19influenza season would almost certainly have a major impact on health care systems, public health officials say. Hospitals in the United States plan for the flu every fall, and systems are built around meeting an expected increase in people sick with respiratory illnesses. But treating a COVID19 outbreak on top of seasonal influenza could topple those expectations and overwhelm hospitals.
“Our hospitals often meet capacity during the flu season. So we’re going to have to have beds available beyond the normal winter surge capacity,” said Dr. Stephen Parodi, an executive vice president and infectious disease expert at Kaiser Permanente. He added that hospitals will also need largerthanusual stockpiles of personal protective equipment.
The good news is that Bay Area hospitals already have built up extra capacity to prepare for an anticipated surge in COVID19 patients that never arrived. Now they’ll need to maintain that, Parodi and others said. But preparing for the possible doublepunch of COVID19 and flu will mean more than just adding beds.
“It’s going to be much more complicated,” said Dr. Bill Isenberg, Sutter Health vice president for patient safety. “It’s like playing threedimensional chess. It’s not just pure and simple flu, it will be that plus COVID.”
Health care systems need to develop practices now to quickly identify suspected coronavirus cases, separate them from others and get them tested. Rapid, accurate testing will be key to staying on top of the flu and COVID19, but most hospitals don’t yet have those tools in place.
For now, flu and COVID19 tests are done separately — flu with a throat swab, coronavirus with a nasal swab — and it takes a day or longer for most places to return results. Doctors hope that by the fall they will be able to test for both viruses with one swab and get results within hours. That would help them quickly get patients to the appropriate care.
Other protocols for preserving limited hospital resources are already in place, and may be expanded in the fall when flu returns. Sutter set up drivethrough respiratory clinics around the Bay Area in March to keep up with demand and help patients avoid office visits that could expose them to the coronavirus. Kaiser used similar clinics to safely see more patients, and Parodi suggested they could be used for vaccinations too.
In fact, vaccination will be a critical tool in addressing a combination COVIDflu season. There almost certainly won’t be a coronavirus vaccine by then, but health care providers will be pushing for more people to get flu shots. Only about half of all Americans are vaccinated against the flu most years — the U.S. needs better coverage than that with the coronavirus also lurking, said Relman with Stanford.
“What we should be doing right now is ramping up production of both — a new, experimental COVID vaccine and influenza vaccine,” Relman said. “And we want to start vaccinating early, not wait until late fall like we usually do. We have to take influenza off the table as much as possible from the very getgo.”
That also means increasing production of Tamiflu, the antiviral used to treat influenza, which could help patients recover faster and in turn free up limited hospital resources, Relman said.
Ordinarily, public health experts would be watching the Southern Hemisphere — which is entering its winter months, and therefore its flu season — for hints of what to expect in the U.S. But places like Australia and New Zealand that are typically the best sources of information have done a far better job of containing their COVID19 outbreaks than has the United States, so they may not be good predictors of how the two viruses will mix.
Another possible source of information would be the United States’ vast flu surveillance network, which monitors reports of influenza and people with flulike symptoms. That system reported some of the earliest signs of an unusual spring uptick in flu cases in the H1N1 pandemic.
The coronavirus now appears to have been circulating through most of the last flu season, but no one was looking for it at first, and later there weren’t enough tests to closely monitor it. It’s possible that COVID19 made the season worse than it would have been, and there was a notable uptick in people reporting flu symptoms at a time when the season should have been winding down. But those reports also fell sharply below average once people started sheltering in place.
In other words: The surveillance data from the past flu season is muddy and difficult to decipher, infectious disease experts say, and therefore not too useful for predicting how the coronavirus might interact with influenza in the coming season.
There’s one potential positive outlook, said Dr. Michael Matthay, a critical care specialist at UCSF. Even after the Bay Area eases stayhome restrictions, people are likely to keep up social distancing practices, such as wearing face coverings or avoiding large gatherings.
Ideally, that will prevent any major coronavirus resurgences, he said. But it could also mean a much milder flu season.