Public health officials have been warning about the possibility of an oncoming “twindemic,” as the persistence of high SARS-CoV-2 infection levels has brought the virus into the Northern Hemisphere winter and, thus, into flu season.
This poses numerous challenges to healthcare systems in affected areas. Ron O’Brien, host of Science with a Twist, spoke with Dr. Stephen Young, Professor Emeritus of Pathology at the University of New Mexico and Director of Research and Clinical Trials of TriCore Reference Laboratories, in his podcast.
Ron O’Brien speaks with Dr. Stephen Young, an expert in Microbiology, with a background in pathology, virology, and infectious diseases. They discuss what we should know during the potential viral storm produced by the collision of the seasonal flu and the COVID-19 pandemic.
“As the weather cools,” Dr. Young explains, “people tend to congregate in groups inside, and that enhances the spread.” This is a fact of life that helps explain the idea of cold and flu season. Pathogens are not directly influenced by seasons, but human behavior makes diseases easier to catch, and that bodes ill for the Northern Hemisphere. This is especially true with winter holidays, where large gatherings have been customary for generations and which often occupy rare stretches of vacation time.
But Dr. Young also sees cause for hope. Masks, frequent handwashing, and distancing are effective against other infectious diseases in addition to COVID-19, and data from the Southern Hemisphere winter suggests that, in places that have enthusiastically embraced these protective measures, the “twindemic” will not be nearly as dramatic as others fear.
“I think the data is fairly compelling that, when you look at the Southern Hemisphere and the absence of influenza virus where they practice social distancing, masks, and handwashing…[It] is compelling enough to me as a virologist to say that this stuff does work.”
Instead of a true twindemic, there may be a smaller spike in influenza and other respiratory infections when these measures are relaxed, such as when a SARS-CoV-2 vaccine becomes widely available, as these conditions return to baseline levels. Time will tell which scenario is the one that unfolds in the United States, Canada, and Europe.
The twindemic is a serious concern for healthcare providers because it complicates differential diagnosis and creates the possibility of patients infected with both simultaneously. IVD multiplex panels, such as those with an Emergency Use Authorization (EUA) label from the US FDA or a CE-IVD mark in Europe, are a benefit here, reducing the time and effort needed for differential diagnosis and enabling treatment to be more specific.
At TriCore Reference Laboratories, these multiplex tests are the first line of testing and can be enough for definitive answers much of the time, since versions exist that can cover both influenza and SARS-CoV-2, respiratory syncytial virus (RSV), and even more pathogens, especially in hospital settings.
Dr. Young highlights an underappreciated reason why knowing which disease affects a specific patient is important: hospitals are major sites of cross-infection and maintaining separate wards for SARS-CoV-2 and influenza infections is critical to keeping both diseases from sweeping through these enclosed, vulnerable populations of people infected with the other.
Additionally, the antivirals used to treat acute SARS-CoV-2 infection differ from those used for influenza and both are most effective early in an infection, making rapid, accurate diagnosis a matter of life and death.
Treating a patient for the wrong condition can be dangerous both in time wasted and in side effects of the unneeded medication, making this a scenario to avoid. Dr. Young hopes that people will seek diagnosis early, when the biggest differences can be made, to keep either deadly disease from spreading in their households and avoid the worst of either.
These complications make flu shots perhaps even more important this year than in other years. Flu vaccines protect against common strains and reduce susceptibility to the flu more broadly, decreasing infection rates and making the remaining cases milder.
“I don’t know that it’ll prevent it,” Dr. Young offers on the subject of the twindemic, but “I would encourage them to get a flu shot this year. My reasoning behind that is, we want to decrease disease burden as much as possible.”
The SARS-CoV-2 vaccines currently exiting initial trials offer some hope, but Stephen suggests cautious rather than celebratory optimism. “This virus will be with us for a while,” he reminds listeners, because of people who reject vaccination or cannot safely be vaccinated, such as small children and elderly people whose immune systems are weakening.
Even if a truly effective vaccine is developed that does not have to be adjusted regularly like the flu shot is, it is unlikely to eliminate the disease entirely within a few months and, without a nigh-universal vaccination regime, it is even less likely to permanently eliminate SARS-CoV-2 the way the smallpox vaccine eliminated smallpox and the polio vaccine is almost done eliminating polio.
Much-vaunted herd immunity, likewise, depends on extremely high vaccination rates that prevents infected people from encountering those susceptible to the diseases they carry, such that the conditions they do contract do not spread farther.
Dr. Young has one more observation from his professional expertise: “What we don’t know are the long-term effects. This virus is very aggressive. It attacks endothelial cells.” With such a new disorder and with mounting evidence that the long-term consequences of infection are severe and only beginning to be understood, it is possible that even asymptomatic people will carry long-term effects that will not be known or even detectable for years to come.
SARS-CoV-2 is a viral threat unlike any modern society has ever faced, and Dr. Young leaves us with one last, poignant thought: “If we don’t sacrifice some of our individual liberties, we won’t survive as a society.”
Thermo Fisher Scientific offers multiplex real-time PCR diagnostic kits for the detecting and differentiating SARS-CoV-2 and other respiratory viruses like influenza and respiratory syncytial virus (RSV). Find out more in our “Differentiating Multiple Respiratory Viruses with a Single Test” blog.
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