The United States is just a few weeks into winter, but this year's respiratory virus season already looks different than last. Both the coronavirus and influenza are rapidly increasing, with no peak in sight.
Influenza and respiratory syncytial virus (RSV) outbreaks started early last winter, but had already declined by the time Omicronvirus hospitalizations began to spike in December 2022.
“What's new this year is that both influenza and coronavirus are circulating at the same time,” said infectious disease expert Dr. Michael Phillips, chief epidemiologist at NYU Langone Health. “This is different.”
NYU Langone has had a slightly higher number of people infected with the coronavirus, with positive tests for influenza and COVID-19, Phillips said.
Dr. Helen Chu, an infectious disease professor at the University of Washington, said health care providers in Washington state are preparing for the impact of the coronavirus and influenza over the coming weeks.
“The Pacific Northwest tends to be one to two weeks behind the Southeast and East Coast,” she says. “I think it’s going to be a pretty bad season.”
The latest data is Centers for Disease Control and Prevention As of the week ending Dec. 30, at least 38 states showed high or very high levels of influenza. The CDC reported that an estimated 10 million people were sickened by influenza last week, up from 7 million the week before.
New coronavirus-related hospitalizations The CDC reported Friday that cases have increased by 20% in the past week.
How common are co-infections?
If both viruses are circulating at high levels, what are the chances that someone will be infected with both viruses at the same time?
Fortunately, contracting the coronavirus or influenza appears to be rare.
Last year, the CDC tracked co-infections in the United States and found that 3% of people hospitalized with the flu also tested positive for the coronavirus. CDC Director Dr. Mandy Cohen told NBC News in December that it appears to be less common this year as well.
“Right now, we don't have anyone testing positive for multiple respiratory viruses at once, but we're seeing a lot of illness,” she told NBC News. “We're seeing about the same level of co-infection as this time last season.”
John Wherry, director of the Institute of Immunology at the University of Pennsylvania, said protection from co-infections involves our bodies' own defense systems.
“There is a concept based on data from animal models that one infection increases resistance to another infection that occurs at the same time,” he says.
This phenomenon, called viral interference, means that infection with one virus strengthens the body's immune system, making it less likely to be infected with another virus.
“The immune response to one species closes the door on others,” said Dr. Jake Scott, an infectious disease expert at Stanford University.
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Scott, who treats patients at Stanford Hospital, isn't currently seeing many patients with influenza or COVID-19.
“I don't recall any patient testing positive for both tests,” he said. “I think that's pretty rare.”
However, it varies from person to person.
“A 22-year-old who has had influenza and recovered very recently may maintain an inflammatory resistance to COVID-19 infection for several days, perhaps even a week,” Wherry said. . “On the other hand, if a frail 87-year-old who has had the flu and is already physically and respiratoryly compromised, were to contract COVID-19 a week later, the impact could be even greater. There is.”
There is evidence that infection with the new coronavirus or influenza can lead to severe illness.
a meta-analysis A study of 95 published in the International Journal of Infectious Diseases in November found that people who were infected with both the coronavirus and influenza at the same time were more likely to need a ventilator or die, especially if infected with the influenza A strain. It turned out that there is a high possibility that They tend to cause more severe illness.
There have been numerous reports of persistent coughs and runny noses this season, but that's not necessarily unusual and doesn't mean someone has multiple viruses.
Even common respiratory infections can take several weeks to recover.
Stanford's Scott said the current high rates of infection for both viruses are reason enough to stay up-to-date on coronavirus and influenza vaccines.
Should I get tested for influenza and coronavirus?
Does it matter if I have the new coronavirus infection or the flu?
Maybe. For example, it makes a difference in how quickly you return to your normal routine.
Regarding COVID-19, the CDC recommends that people quarantine for five days after testing positive or showing symptoms. In the case of influenza, the first three days after the onset of symptoms are considered to be the most contagious. The CDC recommends staying at home until at least 24 hours after fever subsides.
Also, knowing which of the two viruses a person is fighting could be important for people who are at higher risk of getting a severe infection, Phillips said. People over 65, pregnant or immunocompromised can avoid hospitalization if they take the antiviral drug paxlobid during the first few days of coronavirus infection. For influenza, your doctor can prescribe the antiviral drug Tamiflu.
Early last year, the Food and Drug Administration authorized the first at-home test that can differentially detect both the coronavirus and influenza.A new federal program called Tests for treatment We offer free access to tests.
Scott's advice for those who are not at high risk for serious illness is simple. If you are sick, please stay home.
“I get emails all the time from friends all over the country saying, 'Hey, I feel like I have something, should I get tested?'” he says.
In his view, if you're not high-risk and don't qualify for Paxrobid, a positive test won't make much of a difference to the impact of the coronavirus.
Treatment is the same as for coronavirus and influenza and is supportive, meaning plenty of rest, hydration, and isolation.
After all, it's the shot that matters most.
“If you have up-to-date COVID-19 and influenza vaccines, you have nothing to worry about.”
