If you fell ill last winter, it probably didn't really matter whether your sore throat and sniffles were the result of a cold or the flu. This year, with COVID-19 added to the mix of look-alike winter maladies, it's more important to know which virus is causing your illness, because the coronavirus is so contagious and can result in such serious outcomes.
The Centers for Disease Control and Prevention recommend that people with any symptoms of COVID-19, the illness caused by the novel coronavirus, be considered for testing. However, not all experts agree that those with mild symptoms resembling a cold should.
"I think everything needs to be done on a case-by-case basis," said Arnold Monto, an epidemiologist and professor at the University of Michigan's School of Public Health. He pointed out that the average adult can get two or three respiratory infections a year, and children can get up to five. "If we're going to keep testing for everything, it is really going to overwhelm the system," he said.
Emily Landon, the chief infectious-disease epidemiologist at University of Chicago Medicine, disagrees. "There is no way to tell the difference between cold and COVID, especially at the beginning," she said, and the best way to protect your family and others you come into contact with is to get a test.
When to obtain a test "is a very difficult and complex question," Michael Mina, an assistant professor of epidemiology and a faculty member in the Center for Communicable Disease Dynamics at Harvard, wrote in an email. "Medical care is clashing with public health and resource constraints in a way that we are not used to at all in this country."
He added, "Simply, there is no right answer."
Because there is so much overlap between the symptoms of cold, flu and COVID-19, it can be challenging, even for clinicians, to distinguish among them without a test. "We've got a very complicated situation because, as with any respiratory infections, we're dealing with a spectrum, and symptoms don't tell you everything," Monto said.
According to the CDC, with a cold, you can experience sneezing, stuffy nose, runny nose, sore throat, coughing, postnasal drip, watery eyes and fever (not common).
With the flu, you might have a cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, fatigue and fever/chills – although it's important to understand that it's possible to have flu without a fever. Vomiting and diarrhea are more common in children than adults.
Symptoms of COVID-19 again can include sore throat, cough, congestion or runny nose, as well as fever or chills, shortness of breath, fatigue, body ache, headache, loss of taste or smell, nausea or vomiting or diarrhea. The loss of taste or smell is a real tip-off, experts say.
'Apply common sense'
The difficulty in pinpointing which virus is at play may make it tempting for anyone who develops any symptoms to seek a test. Instead of automatically seeking a test, "what I am advocating, as is the case almost universally when dealing with this situation, is apply common sense," Monto said. That means you should assess your symptoms and consider other factors, such as whether you have been exposed to someone who has COVID-19, how much you've been out in public, the infection rate in your area, and any risk factors you have.
"There are no absolutes," Monto said, but "if you are not very sick and believe you have not had contact with somebody who might have COVID, then I would not necessarily go get a test or anything like that if you have mild respiratory symptoms." On the other hand, he said, "if you are having an illness with cough and respiratory difficulty, you better get tested."
"I wouldn't rush in to get a COVID test with a cold," concurred Gary Simon, director of the Division of Infectious Diseases at George Washington University. If you think you have a cold – runny nose, scratchy throat, even a mild cough – he advised staying home as much as possible, making sure to wear a mask and washing your hands frequently if you must go out; if you've had contact with someone who was exposed to COVID-19 or you have a fever, however, you should get a test. He also highlighted the importance of getting a flu shot this year, to cut down on illnesses and because flu and COVID-19 are especially difficult to differentiate.
But Landon sees value in testing people who have mild symptoms. After months of studying COVID-19 patients, she said, "What we're finding is that the vast majority of them have symptoms that are very innocuous in the beginning. They don't even count them really as symptoms. They say, 'Oh, I thought it was just my allergies acting up,' or something like that, and then a day or two later they feel pretty bad, and that's when they go in and get tested."
Because even innocuous symptoms could be COVID-19, she said, "it's not appropriate for people to continue to be going on exposing other people and living their life normally." The policy at the University of Chicago Medical Center is that people can get tested even with very minimal symptoms, she said, adding that she is aware of people being turned away from other facilities for testing because their symptoms were too mild, only for them to get worse and later test positive.
"There certainly is a shortage of tests in many places," Landon said. "It's mind-boggling to me how we can have a shortage given that we've known that we need more and more testing."
Mina, too, lamented the lack of testing. "It is for these situations that we truly need increased access to simple paper-strip-type rapid tests," he wrote, so people can test themselves at home.
Up against a wall
Given the shortage of tests, what should people do if they come down this winter with a mild case of ... something? The CDC offers a symptom self-checker online (putting in sniffles and a sore throat results in notification that the person "may be eligible for COVID-19 testing" and advice to stay home).
"Across the country, one of the best things people can do is be aware of what is happening around them and in their community," Mina wrote. "If flu is going around and COVID is not, and someone has flu-like symptoms, the likely scenario is it is flu."
Anyone who is feeling particularly ill, he added, should call a doctor, who "should be able to have a decent pulse on what viruses are spreading in their community."
"I know it is a fairly vague answer," he said, "but there are no good answers to this one. We are really up against a wall in terms of resource constraints and a lack of clear guidance from the federal level on how to best allocate our tests in a global sense."
When Monto was asked by email whether he would advocate that anyone who feels ill get tested if there were no concern about the testing system being overwhelmed or running out of tests, he responded: "Yes, you could say that. It is a difficult issue and, in a perfect world, we would be tested for everything."