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The Big Lie About the Flu and Coronavirus

A positive flu test is frequently being used as an excuse not to test for COVID-19 — despite the fact that you can definitely have both of them at the time

When Nancy, a 36-year-old pseudonymous labor and delivery nurse in Manhattan, developed a fever, severe aches and a dry cough on March 9th, she was immediately concerned about COVID-19. She went to the ER, where she tested positive for type B influenza, after which they sent her home. The possibility of contracting coronavirus was so terrifying, she was relieved to have a positive flu test and didn’t push things any further. 

But in retrospect, she suspects she may have had the flu and COVID-19 at the same time. “They didn’t want to test me for coronavirus after the flu test came back positive. There just aren’t enough tests,” Nancy tells me. “But I haven’t been that sick in a long time, and I bet it was corona.”

Nancy isn’t an alarmist or alone in her concerns. Due to the Trump administration’s failure to implement a massive testing strategy, many sick health-care workers such as Nancy have been forced to take flu tests as a consolation swab. Meanwhile, analysis from Ian Brown, a physician and clinical associate professor of emergency medicine at the Stanford School of Medicine, reveals that flu tests are being used to exclude COVID-19 in patients, too. 

“Hospitals don’t have unlimited access to COVID testing,” Brown said in a statement. “In some cases, a patient with respiratory symptoms may first be tested for a non-COVID virus. If there is a diagnosis of influenza or rhinovirus, or other respiratory virus, a hospital may discharge the patient without COVID testing, concluding that the alternative diagnosis is the reason for the symptoms.”

The glaring problem is that there’s nothing about having the flu that protects a person from contracting the novel coronavirus, and it’s entirely possible to become infected with both at the same time. “You can absolutely become infected with both viruses at the same time,” physician Taylor Graber confirms, adding that the viruses are opportunistic — meaning they look for hosts to multiply and carry on their life cycles, or replicate their RNA and DNA so the virus can spread further. Despite limited data that suggests some people with the flu are less likely to get colds, viruses don’t not compete for a host, so there’s no reason to expect one to inhibit another. For instance, some people can have multiple strains of the flu at once. 

“If a patient becomes exposed to a person who is contagious for influenza and begins to contract the virus, there’s nothing stopping them from coming into contact with another person the next day who is infected with coronavirus, and becoming co-infected,” Graber warns. 

Co-infection happened to at least one patient in China. According to a recent case study, a 69-year-old man went to a Beijing clinic with a fever and dry cough that had started that day. He’d recently traveled to Wuhan, had an abnormal X-ray and was thought to have COVID-19. Oddly, three nasal swabs for coronavirus came back negative, but he tested positive for the flu. His diagnosis was changed, and he went home. But a week later, he returned to the hospital with shortness of breath and a fever. He tested negative for coronavirus twice more, but was diagnosed with severe influenza A pneumonia and put on a ventilator. His condition improved enough to collect samples from his lungs, which finally tested positive for COVID-19. At the same time, a nasal swab remained negative, even while he was on a ventilator.

It’s worth noting that the study isn’t yet peer-reviewed, but it was published in Emerging Infectious Disease, a CDC publication designed to get patient reports out to doctors and scientists with urgency. Either way, it underscores the need for more accurate testing across the board.

Phil, a 38-year-old pseudonymous physician in L.A., felt this need firsthand when he developed a sore throat and fever on March 3rd. As his symptoms worsened throughout the week, he played it safe and stayed home from his clinic for at-risk youth. By Friday, he could barely make it up the stairs without feeling like he was going to pass out. Panicked, he called several urgent care centers. 

“They all told me to stay home unless I needed a ventilator,” he tells me. He tried calling the ER, but they transferred him to an automated message about hand washing. On Sunday, he went to urgent care, where they wouldn’t give him a test because he was not critically ill. It wasn’t until he went to the ER the following day that he got a flu swab, nine days after his initial symptoms set in, which came back negative. Yet again, he was sent home without a coronavirus test or a clear recommendation to stay home from work. The decision to self-quarantine was up to him, which he did.

“It’s not even about me. I’ll probably get through this, but I need to know if I can go back to work and if I’ve already put my patients at risk,” Phil laments. Eventually he received a coronavirus test from his primary care doctor 15 days after experiencing symptoms, which came back negative. But he believes it was false negative, an error that occurs approximately 30 percent of the time. “I’m going to get antibody testing as soon as it’s possible because I’m certain I had COVID. I was sick for 24 days,” Phil says. 

Nancy tried her best to quarantine, but could only afford to take 12 days off of work without an explicit diagnosis. She’s also worried about being out of a job. It sounds counterintuitive, but outside of the ER, ICU and COVID-19 clinics, many health-care workers are in danger of layoffs as non-essential appointments and elective surgeries are cancelled and postponed. Fortunately for her, people keep having babies, and she has a N95 respirator mask and enough protective gear (at least compared to other health-care workers in New York). But as more new mothers come into her hospital testing positive for COVID-19, Nancy feels more conflicted about if she did the right thing. 

“Maybe I should’ve pushed for a test because I’m a nurse, but they really didn’t seem too keen on the idea of testing me,” she says. “We’re so underprepared for this, it’s really insane.”

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