Coronavirus Symptoms Can Last for Weeks Even in Mild Cases, Preliminary Study Shows

Symptoms of COVID-19 can last for weeks in patients who don't need hospital treatment, according to a preliminary study.

In a group of 272 COVID-19 patients, 41 percent had a cough three weeks after their symptoms started, 24 percent had shortness of breath when they exerted themselves, and 23 percent couldn't smell or taste. A further 23 percent had sinus congestion, and a fifth had headaches.

The authors of the paper wrote: "Symptoms of acute COVID-19 frequently last longer than the minimum duration of isolation and patients and healthcare providers should be aware that symptom resolution may be gradual."

The participants were diagnosed with the disease caused by the coronavirus using nasal swabs. They were treated at the COVID-19 Virtual Outpatient Management Clinic in Atlanta, Georgia, which checks in with patients who are at home until their symptoms improve. The patients presented to the clinic within 10 days of their symptoms starting, and within five days of having their coronavirus test.

The researchers looked at data on patients who healthcare workers followed up with for an average of 20 days, to ask whether or not they had certain symptoms. Calls took place every 12 to 48 hours depending on how severe the patients' symptoms were.

The most common symptoms were a cough, headache, loss of smell or taste, sinus congestion, and body aches. Fewer patients had gastrointestinal symptoms, but they could also last for a relatively long period of time, with 10 percent suffering with diarrhea for the three weeks they were followed up.

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The authors acknowledged their study had a number of limitations, including that data on fevers may be incomplete as patients were asked whether they had a "current fever."

The researchers wrote in their paper that it "highlights the persistence of symptoms that may interfere with usual activity, such as shortness of breath with exertion."

The findings were released on the pre-print website medRxiv, meaning it has not been through the rigorous peer review process required to publish in scientific journals. Releasing studies this way enables scientists to prompt debate on a topic and are particularly useful at a fast-moving time like a pandemic.

Experts who did not work on the paper said the study was interesting because it sheds light on how long symptoms can last.

Dr. Joshua Barocas, assistant professor of medicine at Boston University School of Medicine and Boston Medical Center, told Newsweek via email: "From this study, we can see that symptoms that can be concerning can persist for at least three weeks, and probably longer. This helps clinicians with expectation setting with patients. This is not a disease that simply just 'goes away.'"

Barocas said although he had anecdotally seen patients with gastrointestinal symptoms, he was surprised by the "persistence" of symptoms in the study group.

The findings were limited, Barocas said, because they came from one center, and it was also unclear whether the patients had any treatments for their symptoms, either prescribed or over the counter, which may have skewed the findings.

"Additionally, still unknown is how long these patients were shedding virus and how long they were actually infectious. This is a key piece that is missing from the literature at this point."

Stephen Durham, professor of allergy and respiratory medicine at Imperial College London, told Newsweek that as well as confirming that a cough, headache, and loss of smell are common in COVID-19 patients and the coronavirus involves many bodily systems, the paper also draws attention to sinus congestion as a potential symptom—which has not been so widely reported.

Durham said the study also suggests that the loss of smell is an important differentiator of COVID-19, for instance from other conditions like the flu.

Echoing the authors of the study, Durham said fever is likely underestimated in the paper. It is important to ask patients to record their temperatures, he said.

The study also failed to answer whether those with symptoms could still carry the virus as the patients weren't repeatedly tested with swabs. "This is unfortunate as it may have informed the necessary duration of quarantine necessary in relation to persistent symptoms," said Durham.

According to Johns Hopkins University, more than 7.3 million people have been diagnosed with COVID-19 since the pandemic started late last year. As the graph by Statista below shows, the U.S. is the country with the most known COVID-19 cases.

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Coronavirus Symptoms Can Last for Weeks Even in Mild Cases, Preliminary Study Shows | Health