Long before the COVID-19 virus, our immune systems were well accustomed to the annual wintertime bombardment of viral respiratory invaders.
Most common wintertime viruses cause mild upper and lower respiratory illnesses that are self-limited, meaning that people with healthy immune systems can clear them within a few days to weeks without medical intervention. However, some wintertime viruses, such as influenza, can be a larger threat.
Read on to learn more about the most common non-COVID-19 wintertime viruses and how to manage this winter.
How Common Will Non-COVID-19 Viruses Be This Winter?
Even with social distancing, hand washing, and mask-wearing, medical authorities still anticipate an increased number of respiratory infections from viruses this winter, as is typical of the coolest season of the year. As temperatures drop in the Northern Hemisphere, people return indoors, providing viral pathogens with the perfect opportunity to circulate and spread.
The majority of these wintertime viruses will likely not be the COVID-19-associated SARS-CoV-2 virus but, instead, other viruses. This is because even at the SARS-CoV-2 virus's infectious zenith this spring in New York state, positivity rates only approached 50 percent, meaning that only 50 percent of people with viral symptoms (like fever, cough, congestion, or sore throat) who got a COVID-19 test were positive for COVID-19. The other 50 percent of folks tested negative and were presumably suffering from a different, non-COVID-19 virus.
What Are the Most Common Non-COVID-19 Wintertime Viruses?
The following viruses are the most common non-COVID-19 wintertime viruses, with which we have coexisted for many years.
Influenza, known colloquially as the flu, is a viral illness that has a seasonal uptick in the wintertime. Generally, four to five subtypes of the virus predominate during any given flu season, which is why flu shots are multivalent, meaning they target more than one version of the virus. Symptoms of influenza can include fever, chills, body aches, nasal congestion, cough, sore throat, headache, and fatigue. Most people are able to manage the flu at home with supportive measures such as over-the-counter medication and hydration (or even a prescription anti-flu medication, such as Tamiflu), but people who become very ill with influenza may need care in the hospital to support their breathing and hydration.
Last year, there were as many as 62,000 deaths and 740,000 hospitalizations from influenza in the United States alone. Experts are unclear about how influenza may affect the U.S. during the upcoming 2020–2021 flu season, and many have highly advised flu vaccination for every citizen over the age of 6 months to mitigate possible risk. However, given its recent mild impact in the Southern Hemisphere, flu season may be attenuated this winter because of public health campaigns aimed at reducing the spread of the COVID-19 virus.
Parainfluenza is a viral illness that commonly causes the childhood illness known as croup, although it can cause other types of infections in both children and adults, as well. Symptoms of the parainfluenza virus, which has several subtypes, can include cough, runny nose, fever, and chills.
Human rhinovirus is a notorious culprit when it comes to the common cold, with up to 25 percent of adult colds being caused by one of its 100 subtypes. Symptoms generally include stuffy or runny nose, sore throat, and cough.
Respiratory Syncytial Virus
Respiratory syncytial virus (RSV) is the most common cause of respiratory infections in children younger than age two; however, people of all ages can contract an RSV infection. Typical symptoms are generally similar to those of the common cold. Specific anti-RSV medications are available for especially vulnerable populations, particularly infants who become very ill with an RSV-related illness known as bronchiolitis.
Human metapneumovirus is another viral illness that can cause respiratory symptoms such as fever, cough, stuffy nose, or shortness of breath. Human metapneumovirus is in the same family as RSV and also can affect both children and adults.
Adenovirus, which is common in both children and adults, primarily causes infections in the respiratory and gastrointestinal systems. It can also cause an eye infection known as conjunctivitis or pink eye. Most adenovirus illnesses are mild and resolve on their own; however, very young children, older adults, or immunocompromised people can have a more severe course.
Certain strains of coronavirus have been circulating in the population for years — specifically the subtypes 229E, HKU1, NL63, and OC43 — and they account for an estimated 10 percent of all cold-like illnesses. These seasonal coronaviruses generally cause mild symptoms, such as cough and runny nose, and are distinctly different from the novel SARS-CoV-2 coronavirus that causes COVID-19 illness.
How Are Non-COVID-19 Viruses Detected?
While many viral infections are determined on a clinical basis, meaning that a clinician makes a diagnosis via history and physical exam alone, many healthcare organizations have access to specific viral testing. Generally known as respiratory viral panels, these tests can rapidly screen for the presence of several of the most common non-COVID-19 wintertime viruses. Although knowing exactly which virus you have generally does not change your treatment plan, specific respiratory viral testing may be particularly helpful this winter in ruling out specific possibilities and providing peace of mind when it comes to the COVID-19 virus.
What To Do if You Are Feeling Ill With Viral Symptoms
For most healthy people, wintertime viral respiratory infections — even COVID-19 infections — will be defeated by the immune system without assistance. However, it is important, particularly if you are immunocompromised, to contact a medical provider if you are experiencing severe symptoms of any sort, such as shortness of breath, dizziness, inability to hold down fluids, or severe pain.
Libby Pellegrini is a nationally certified physician assistant. She has worked in numerous healthcare settings, including the rural United States, an inner-city Level I trauma center, several suburban acute care centers, and a boutique, personalized medicine clinic in Southeast Asia. She graduated Magna Cum Laude from Northwestern University's Medill School of Journalism.