DULUTH — If you’re coughing, have a fever and are struggling to breathe, you might have COVID-19.

If you’re not coughing, don’t have a fever and aren’t struggling to breathe, you still might have COVID-19.

“If you look at the medical literature, nothing’s 100%,” said Dr. Susan Kline, an infectious-disease physician who is a professor at the University of Minnesota Medical School.

Kline endorsed the chart accompanying this story. Modeled after a chart from the Carver County Public Health Department, it outlines 11 symptoms and the likelihood of each occurring with influenza, the common cold, allergies and COVID-19.

The chart shows cough, fever and breathlessness as the most common symptoms of COVID-19. On the other end, runny nose and sneezing are shown as “rare” and watery eyes as “none.”

After seeing the Carver County version of the chart, Kline agreed with it, but with the caveat noted above. Although fever is frequently symptomatic of COVID-19, for example, it’s not always present — even in severe cases.

Kline cited a study from the New England Journal of Medicine of 1,000 Chinese cases of the illness.

“The most common symptom is cough,” she said. “But that’s only 68% of patients.”

Fever is even less of a sure thing, at least according to that study, Kline said. Only 44% of the patients had a fever when they went to the hospital, and only 48% of those whose cases were considered severe. That rose to 90% among those who remained hospitalized over a period of time.

But individuals have died of COVID-19 without ever developing a fever, Kline said.

“They’re dying from hypoxia, which is lack of oxygen," she said.

On the other end of the scale, the journal’s study showed fewer than 1% had irritated eyes, about 5% had nasal congestion, about 14% had headaches, 14% had sore throat, 33% coughed up phlegm and 38% reported fatigue.

“I will say that we’ve had more and more case reports from more mildly ill people that fatigue was a big part of it,” Kline said. “All of the sudden they became extremely fatigued.”

In the telephone interview, Kline responded to a couple of additional questions about COVID-19:

  • It’s well-known by now that people can have COVID-19 without having any symptoms, she said. What isn’t clear yet is whether people who are without symptoms can spread the disease. “But it is thought that people, probably in the day or so or half-day before they have symptoms, could be infecting other people.”

  • It’s not known to what extent having had COVID-19 provides future immunity from the disease, Kline said. Data suggest that some coronaviruses that cause colds can leave the individual immune for one to three years. For SARS, data seemed to show a longer-lasting immunity. But nothing is conclusive. “This is the first time we’ve ever had this disease,” she said. “So we don’t know. We don’t know if a year from now or two years from now someone could get it again.”

Kline’s bottom line: Symptoms aren’t a foolproof barometer.

“(The) chart and what we doctors were told as well is that the most common symptoms are fever, cough and shortness of breath,” she said. “And yet, I think we have to realize not everyone's going to have those three symptoms.”

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