Broadway actor Nick Cordero dies of coronavirus at 41

Conventional wisdom suggests that when a sickness is mild, it’s not too much to worry about. But if you’re taking comfort in World Health Organization reports that over 80% of global Covid-19 cases are mild or asymptomatic, think again. As virologists race to understand the biomechanics of Sars-CoV-2, one thing is becoming increasingly clear: even “mild” cases can be more complicated, dangerous and harder to shake than many first thought.

Throughout the pandemic, a notion has persevered that people who have “mild” cases of Covid-19 and do not require an ICU stay or the use of a ventilator are spared from serious health repercussions. Just last week, Mike Pence, the US vice-president, claimed it’s “a good thing” that nearly half of the new Covid-19 cases surging in 16 states are young Americans, who are at less risk of becoming severely ill than their older counterparts. This kind of rhetoric would lead you to believe that the ordeal of “mildly infected” patients ends within two weeks of becoming ill, at which point they recover and everything goes back to normal.

While that may be the case for some people who get Covid-19, emerging medical research as well as anecdotal evidence from recovery support groups suggest that many survivors of “mild” Covid-19 are not so lucky. They experience lasting side-effects, and doctors are still trying to understand the ramifications.

Some of these side effects can be fatal. According to Dr Christopher Kellner, a professor of neurosurgery at Mount Sinai hospital in New York, “mild” cases of Covid-19 in which the patient was not hospitalized for the virus have been linked to blood clotting and severe strokes in people as young as 30. In May, Kellner told Healthline that Mount Sinai had implemented a plan to give anticoagulant drugs to people with Covid-19 to prevent the strokes they were seeing in “younger patients with no or mild symptoms”.

Doctors now know that Covid-19 not only affects the lungs and blood, but kidneys, liver and brain – the last potentially resulting in chronic fatigue and depression, among other symptoms. Although the virus is not yet old enough for long-term effects on those organs to be well understood, they may manifest regardless of whether a patient ever required hospitalization, hindering their recovery process.

Another troubling phenomenon now coming into focus is that of “long-haul” Covid-19 sufferers – people whose experience of the illness has lasted months. For a Dutch report published earlier this month (an excerpt is translated here) researchers surveyed 1,622 Covid-19 patients with an average age of 53, who reported a number of enduring symptoms, including intense fatigue (88%) persistent shortness of breath (75%) and chest pressure (45%). Ninety-one per cent of the patients weren’t hospitalized, suggesting they suffered these side-effects despite their cases of Covid-19 qualifying as “mild”. While 85% of the surveyed patients considered themselves generally healthy before having Covid-19, only 6% still did so one month or more after getting the virus.