Almost a third of people infected with the new coronavirus could suffer long-term ill-effects, including damage to their lungs and brain, according to leaked guidance document  For Britain’s National Health Service (NHS),

“Around 30% of patients who recover from Covid-19 may be left with damaged and scarred lung tissue,” reports  The  Daily Telegraph, which has seen the NHS England advice for GPs and community services.

“This could amount to around 100,000 of the 300,000 people who have so far tested positive in the UK.”

Since the early stages of the outbreak, doctors have been warning that “many patients will emerge from the shadow of the immediate threat of the disease only to face a range of long-term problems”, says the  Daily Mail.

In May, Professor Nicholas Hart - who treated British Prime Minister  Boris Johnson when he was hospitalized with Covid-19 - described the disease as “this generation’s polio”.

“Large numbers of patients will have physical, cognitive and psychological disability post-critical illness that will require long-term management,” Hart added. “We must plan ahead.”

Like much about the outbreak, the long-term effects of the new coronavirus are still shrouded in uncertainty.

“Covid-19 has existed for less than six months, and it is easy to forget how little we know about it,” says The Atlantic. Even with more established diseases, “the aftermath of viral infections is poorly understood”.

One mystery is why even young, healthy Covid-19 patients who recover without needing hospital treatment are suffering from persistent problems. Some have “been flattened by relentless and rolling waves of symptoms that make it hard to concentrate, exercise, or perform simple physical tasks”, the magazine reports.

In fact, “people with mild cases of the disease are more likely to have a variety of strange symptoms that come and go over a more extended period”, according to the Covid Symptom Study, a collaboration between King’s College London and health science company Zoe. 

These patients’ plight is one of many unanswered questions about Sars-CoV-2, the virus that causes Covid-19.

Over the past few months, says BBC Future, “it has become increasingly clear that Sars-CoV-2 is not just a turbocharged version of the virus that causes the common cold: it has a number of quirky, unusual and sometimes terrifying traits”.