THE PLIGHT of people who recover from Covid-19 but are left with debilitating symptoms for weeks afterwards is the subject of Professor John Wright's latest blog for the BBC.

In it he talks to two young women who are suffering many weeks on - Amira Valli, a doctor from a neighbouring hospital, get out of breath when climbing a flight of stairs while Molly Williams, a physio at BRI who has always been super-fit athlete, says "being breathless is becoming my norm".

Dr Wright, a leading epidemiologist of Bradford Royal Infirmary (BRI), said when patients who had recovered from the acute viral illness were applauded off the wards it would be the last they saw of them.

He said: "Back in March we knew so little about this virus. We assumed that it was a respiratory illness, only to find out that it affects almost every organ in the body. We assumed that we would rely on invasive ventilation and ICU only to find out that early CPAP (non-invasive ventilation with oxygen) on the medical wards was more effective.

"Four months on, and this new foe has become an old foe, and sometimes it seems our only foe. We have also become increasingly aware of the longer-term legacy for patients - not just those who have been in hospital, but those who have self-treated at home and recovered from the acute infection only to suffer from relapses and persistent symptoms. Patients who had the infection months ago are struggling to resume their normal lives.

"We know from studies of patients who had Sars - one of the family of coronaviruses - back in the 2003 epidemic, that almost half of survivors went on to have chronic fatigue or other long-lasting symptoms. So it should not be a surprise that this cunning descendant, Sars-CoV2, should have a similar inheritance.

"We are getting an increasing number of desperate emails and letters from patients and their GPs asking for help. Some are still suffering from the original symptoms of chest pains and breathlessness. Others have newer symptoms - headaches, memory loss and visual problems.

"Many have depression and anxiety. Most of them have persistent, chronic fatigue. All of them want their previous lives back. They celebrated their initial Covid-19 survival in haste and some are now filled with nagging doubt and deepening despair."

He says that Dr Valli's symptoms were quite mild. She thought she was getting over it but the next week she developed breathlessness and that has stayed with her for weeks.

Dr Wright also says she is becoming anxious and, although her chest x-ray is normal and her chest sounds normal, "something is not right and we will try to find out what it is".

He said like Dr Valli, physiotherapist Molly Williams almost certainly caught the virus at work in the hospital. She is one of the top 20 CrossFit athletes in the UK but she too is experiencing breathlessness.

Dr Wright said: "We don't yet understand why these patients are having such long-term problems.

"It is possible that the virus is lingering in reservoirs in their bodies and causing persistent symptoms, as we saw in survivors of ebola. Some of our patients are positive for the virus weeks after they first became infected but this is probably due to antigen-testing picking up residual fragments of the viral RNA.

"If so, these RNA fragments could be triggering a prolonged immune response that explains the persistent symptoms.

"But more likely, these long-haulers are experiencing a prolonged and exaggerated immune response to the original infection, on top of the damage caused to their lungs and other organs.

"Our challenge as doctors and researchers is to find out more about what causes these long-term effects and then develop treatments that help these patients, and others with similar post-viral chronic fatigue.

"This is a neglected area of research, because it is so difficult to find answers, but Covid-19 has been an incredible catalyst for science and discovery, and the spotlight on these long-haul survivors may help advance our understanding."

Dr Wright says in his blog that a colleague Dr Paul Whitaker has set up BRI's first Covid-19 survivors clinic to follow up on patients 12 weeks after their discharge from hospital with referrals being accepted from GPs.

"I think there could be a big iceberg out there of people who've had Covid-19 and just haven't got back to normal. Every week I'm getting three or four phone calls from GPs who are saying they've seen a patient who had Covid a couple of months ago, and they're still symptomatic," Paul Whitaker says.

"In the clinic we're running we're going to be having a dietician, a physiotherapist, as well as a lot of psychological input, because patients are developing the cardiorespiratory complications, but they're also developing post-traumatic stress, anxiety, depression, and they've got neurological symptoms and chronic-fatigue-like symptoms.

"And so how we can support them, how we can set programmes in place - either psychological programmes or rehabilitation programmes - is going to be really important. And we need good evidence about what works."

Rob Whittaker, a consultant clinical psychologist, says waves of tearfulness among Covid-19 survivors are very common and there is "an emerging picture" regarding cognitive difficulties.

"But it's really hard at the moment to tease apart what's to do with fatigue and emotional, or what might be more organic. It's too early to say."