After being hit with surging patient populations, supply shortages and other sudden challenges brought on by the pandemic, hospitals in previous COVID-19 hot spots are once again preparing for the unknown: an influenza season that could coincide with a resurgence of coronavirus.

The Washington state-based Providence St. Joseph Health, which treated the first confirmed COVID-19 patient in the U.S. and was at one point at the epicenter of the nation's outbreak, has been preparing for months for a combination of the flu season and a surge in coronavirus cases.

"If you're Amazon, you know the Christmas season is going to be busy, right? If you're in healthcare, you know the flu season is going to be busy," Amy Compton-Phillips, executive vice president and chief clinical officer for Providence, said in an interview with S&P Global Market Intelligence. "This isn't rocket science to know that you've got to prepare for that."

Using data from February, March and April to project the possible impact of a resurgent pandemic has been helpful for the hospital system, as has been studying data from past influenza seasons. But there is only so much that can be known, as the U.S. is just weeks away from possible fall and winter spikes, Compton-Phillips said.

"Our worst-case scenario is if we have a bad flu season together with a bad COVID season, that will be our upper bound. If we have a good flu season, together with a good COVID season, that'll be our lower bound," Compton-Phillips said. "How do we get ready for everything between those two bounds?"

Looking to the southern hemisphere, which experiences the flu season first, is not helpful for modeling this year because "the whole world was staying home" and dampening transmission of the influenza virus, she added.

Reliable current data is crucial as the impact of flu can vary widely year-to-year. During the 2017-2018 season, influenza caused an estimated 810,000 hospitalizations and 61,000 deaths, according to data from the U.S. Centers for Disease Control and Prevention. These numbers dropped for the 2018-2019 season, when the flu caused an estimated 490,600 hospitalizations and 34,200 fatalities.

Emergency preparedness and testing

New York-based Northwell Health Inc. quickly developed similar strategies to Providence as COVID-19 cases started to fall and the city, which was one of the worst-hit regions of the U.S., began to reopen.

"First of all, historically, if you look back at things like the 1918 [Spanish flu] pandemic, the fall was worse than the spring," Mark Jarrett, Northwell Health's chief quality officer and deputy chief medical officer, told S&P Global Market Intelligence. "So, we have that as a historical fact that we have to watch."

Having seen a peak of about 3,500 COVID-19 patients across the system by mid-April, with over 800 patients on ventilators, Northwell Health is creating emergency plans that can be turned on if necessary, Jarrett said. For example, if predictive models show increases in community positivity rates and admission rates start to climb, the hospital can shut down some elective care and utilize extra spaces and beds.

The system has prepared for a range of outcomes, with worst-case models built on potential volumes climbing to 10% above peaks seen earlier in the year.

"We don't know how bad it will be," Jarrett said. "We're hoping it won't be [bad]. But again, we can't predict."

One key challenge will be differentiating patients being admitted with the flu from those with COVID-19 — as well as managing those with both viruses, which doctors have not yet dealt with, according to Jarrett.

Testing will play a crucial role in this process, but the U.S. still has testing challenges, Compton-Phillips said. "We hear things come in from the government on how testing is easy now, and it's not ... We simply do not have capacity to test everybody, for everything."

Widespread antigen testing will be "the breakthrough," she added.

While there are some concerns about the availability of personal protective equipment, Jarrett said that staff availability could become the biggest challenge. During New York City's peaks, doctors and nurses came from around the country to help.

However, if there are widespread surges of patients in multiple states, staffing resources "will probably dry up," he said.

'Contingent on the community'

While COVID-19 initially erupted in Washington state and New York City, by May and June states like Florida, Arizona and Texas had become pandemic hot spots.

Hospitalizations from COVID-19 peaked in July at over 10,000 total hospitalizations, according to a tracker from the Texas Department of State Health Services. Total hospitalizations have dropped to 3,195 as of Sept. 23.

After managing the day-to-day emergencies of the crisis, hospitals quickly began preparing for the flu season. The Texas Hospital Association coordinated a campaign beginning in August that centered on ensuring patients got vaccinated.

"Hospitals are pushing [the] flu vaccine among their patients, vaccinating healthcare staff and other frontline workers. They're ordering and stockpiling [the] vaccine, launching their own public outreach program, reaching out to patients through patient portals ... hospitals are doing everything they can to be ready," Carrie Williams, vice president of communications for the Texas Hospital Association, said in an interview.

The decline in certain treatments throughout 2020, whether through canceled elective care or patients' hesitancy to go to doctors' offices and hospitals, could create additional challenges along with the flu and the pandemic.

Compton-Phillips said that while childhood vaccinations are climbing back up, they "dropped like a rock" in the spring, and treatments like mammograms, colonoscopies and diabetes management have also been delayed.

"We're now playing catch up," Compton-Phillips said. "That absolutely worries us ... Will we have an epidemic of measles because people aren't vaccinated, much less the flu?"

Regions across the U.S., including Washington and New York City, had measles outbreaks in early 2019, which required additional funding and public health resources to get under control.

If delaying care continues, including among patients who believe they have the flu, it could be another complication for hospitals as "preventable conditions turn into preventable deaths," Compton-Phillips said.

She agrees with Jarrett and Williams that one bright spot might be that practices people are already doing, such as social distancing and mask-wearing, can limit the severity of the flu season as well as the spread of COVID-19.

"The way we respond collectively in a pandemic is to do the things it takes to keep your neighbor safe and keep your family safe, which is wear a mask, wash your hands and stay socially distant," she said. "As long as we do those things, I think that a resurgence in the fall should be manageable."