EXECUTIVE SUMMARY

Countries in the Southern Hemisphere reported mild flu seasons, but that does not necessarily mean the same will hold true in the United States. Experts recommend U.S.-based EDs anticipate what resources they will require if the upcoming flu season is severe, and consider what testing strategies they will employ when patients present with respiratory symptoms that could be flu, COVID-19, or both.

  • Generally, patients under investigation for COVID-19 are placed in universal precaution measures, a much more robust monitoring level than droplet precautions, which are required for suspected flu-positive patients.
  • Some sophisticated testing platforms can look for multiple viruses at once, but such resources may become constrained. This may require frontline providers to optimize supplies.
  • Rapid testing platforms that can deliver results quickly are beneficial, but it is unclear how accessible these tests will be to EDs across the country.
  • Pay close attention to flu and COVID-19 co-infection cases and how such an occurrence could affect disease severity.

If there has been any good news lately, it is that countries in the Southern Hemisphere reported much lower rates of influenza this year. That does not ensure the U.S. flu season will be mild, but it is an indication that the preventive steps taken to stop COVID-19 may be dampening circulation of the flu, too.1

“If, in the United States, we continue to mask and social distance, it is possible we could have a less severe flu season. But if those measures are relaxed, then we would probably have a normal, hard-to-predict severity flu season,” states Catharine Paules, MD, an infectious disease physician at Hershey Medical Center in Hershey, PA.

Despite the positive indications from the Southern Hemisphere, U.S. frontline providers must anticipate fresh challenges as the flu season unfolds.

“One of the biggest challenges will be trying to understand which patients might have flu vs. those who might have COVID-19, and I think we won’t know in many cases,” explains Jeremiah Hinson, MD, PhD, a clinician, researcher, and assistant professor of emergency medicine at Johns Hopkins School of Medicine.

Consequently, Hinson notes the most likely way emergency providers will deal with such cases is by subjecting all those patients not to droplet precautions (typically in place to guard against flu transmission) but with the higher-level universal precaution measures in place for COVID-19. These measures include contact, droplet, and airborne precautions, which are a lot harder to execute.

Anticipate Needs

Testing presents more challenges. There are sophisticated devices that can test for multiple viruses at once, but resources may become constrained.

“One of the things we are going to be looking at is how to determine ... which patients we should test [for both flu and COVID-19], and which patients we might only test for the flu,” Hinson explains. “Algorithms for that are something that we are working on.”

Hinson notes providers have never been in this situation before. They probably will have to learn from the beginning of this flu season what is the best way to test, then see if they can avoid testing certain patients.

Paules notes anyone who presents to her ED with any type of COVID-19 symptom, including fever, cough, or shortness of breath, would undergo a COVID-19 test.

“There is a way to test for both [flu and COVID-19] viruses at once,” she explains. “There is also a respiratory virus panel that tests for COVID, flu, and several other respiratory viruses.”

A big consideration is the fact healthcare systems have seen many shortages of testing supplies throughout the pandemic. For instance, Hinson notes the cartridges used to run some tests have been in short supply, as have the reagents used to store respiratory samples while they are in transit to the lab. Even swabs used to collect samples have been hard to access in some regions.

Providers must act wisely if they want to change patient management. “You don’t really want to do a test, even if it gives you additional information, if there is nothing you can do with that information,” he explains. “For instance, if you have a patient who meets all of the CDC criteria for getting Tamiflu, and the suspicion is very high that the patient has flu, you may not [order] a flu test. You would just treat them.”

During the upcoming flu season, there may be patients who arrive with symptoms that could be flu or COVID-19 — but they also may appear well, and they do not meet the criteria to receive antiviral agents for the flu.

“[In that instance], the only thing we want to know is whether that person, when [he or she] goes home, needs to isolate, whether the patient is infectious for COVID-19,” Hinson explains. “We might only test that patient for COVID, and not for the flu.”

Consider Rapid Tests

“Rapid testing for patients who are under isolation for COVID-19 can actually have a really big impact on your resources,” notes Hinson, referring to recently available tests that deliver results quickly. “For a patient who is thought to have COVID-19 and is a person under investigation [PUI], the longer that person is under investigation ... the longer the people caring for him are using limited [supplies of] PPE [personal protective equipment] and expensive cleaning procedures. The sooner you can get to a negative diagnosis for a [PUI] inside the hospital setting is probably for the better.”

Consequently, EDs with access to rapid testing platforms can create streams of workflow so patients who are physically cohorted under isolation precautions for COVID-19 are those who undergo rapid tests. Meanwhile, other testing can be syphoned into a separate work stream where patients receive a less rapidly processed test.

Patients who are seen immediately and designated for discharge regardless of test results do not require rapid tests. “You can use a systems-based approach in your ED so that you can make the most of whatever infection control resources you have for COVID-19,” Hinson shares.

Johns Hopkins uses an automated, molecular test that can deliver results in 45 minutes. Other companies have developed similar platforms, but it is unclear how quickly such systems will be available.

“The supply has been increasing over time,” Hinson observes. “I know that all of these companies are rapidly expanding their production.”

Prepare for Surges

Knowing which respiratory illness a person has carries implications when it comes to treatment, particularly in critically ill patients. Supportive care is a mainstay treatment for flu and COVID-19 patients, but recent data show steroids may be helpful in some patients with COVID-19.2

“If a person is sick enough to need oxygen, [the patient] tends to do better when [he or she] receives dimethazone,” notes Hinson, referring to a steroid drug that has been studied in COVID-19 patients.

However, steroids have not been as promising when given to patients with flu. In fact, some data suggest steroids could result in harm for subsets of patients with flu.3

One issue that warrants close observation is the incidence of flu and COVID-19 co-infection. At this point, it is unclear how common this might be in the months ahead. “I also don’t think we have a lot of data right now about how much more severe the disease is when people are co-infected with COVID-19 and influenza,” Hinson adds.

There are two questions researchers will investigate in the coming months. First: Is a person who is co-infected with COVID-19 and flu at higher risk for worse outcomes? “We would hypothesize that they are, but we don’t know that,” Hinson offers.

Second: If a person contracts either the flu or COVID-19, does that make him or her more likely to contract the other illness? “We just don’t have that information yet, but these are things we will look at,” Hinson explains.

Not really knowing how the upcoming flu season will unfold or how the COVID-19 pandemic might progress, emergency providers must focus on ensuring they have access to maximum resources, especially PPE, and that their testing platforms are sorted out. “Every hospital’s preparedness is going to look a little bit different based on the hospital itself, the patients it serves, and what kind of resources [clinicians] have at their disposal,” Paules shares. “My general recommendation would be to prepare as if there could be a very severe respiratory viral season this year. Plan for large surges of people with respiratory illness. Hopefully, that won’t happen, but I think we need to prepare as if it will.”

REFERENCES

  1. Olsen SJ, Azziz-Baumgartner E, Budd AP, et al. Decreased influenza activity during the COVID-19 pandemic — United States, Australia, Chile, and South Africa, 2020. MMWR Morb Mortal Wkly Rep 2020;69:1305-1309.
  2. WHO Rapid Evidence Appraisal for COVID-19 Therapies (REACT) Working Group. Association between administration of systemic corticosteroids and mortality among critically ill patients with COVID-19: A meta-analysis. JAMA 2020; Sep 2. doi: 10.1001/jama.2020.17023. [Online ahead of print].
  3. Lansbury L, Rodrigo C, Leonardi-Bee J, et al. Corticosteroids as adjunctive therapy in the treatment of influenza. Cochrane Database Syst Rev 2019;2:CD010406.