British doctor Jake Suett had only been treating severely sick coronavirus patients for a week in a hospital in the eastern English county of Norfolk before he, too, fell ill.
That was back in March, just as the pandemic started to unfold in Britain.
Now, more than three months later, he hasn't been well enough to return to work and is suffering from what he terms "post-COVID syndrome." The 31-year-old intensive care specialist, who was healthy and had no pre-existing health conditions before he became infected, still suffers from breathlessness, blurred vision and episodes of high temperature.
Much of the public focus on the coronavirus, which causes the COVID-19 disease, has been on the death tally. In countries across the world, politicians and officials lament the daily death toll and are anxious to advertise how many of the infected have recovered. But the broad-brush announcements are masking a lot — Suett and other doctors say thousands will struggle to recover from the effects of the disease.
And some may never recover and likely will suffer long-term health consequences.
Thousands of the "recovered" are already suffering from chronic fatigue syndrome and other debilitating conditions. Suett told Britain's Sky News "things have improved" since he "spent three days just gasping for breath in bed" at the peak of his illness, but not by much "and only very, very slowly."
He added, "I've had gastrointestinal symptoms and shooting pains in my hands and feet too."
Britain's Chartered Society of Physiotherapy says tens of thousands of those who contracted the coronavirus and suffered severe symptoms will encounter long-term illness. The most serious patients are often debilitated. The ailment puts a strain on the respiratory muscles which become less efficient, according to Marta Lazzeri, an Italian respiratory specialist. "These patients report that they often feel tired, even struggling to shave or have a shower," he added.
Doctors say a proportion of those who become seriously ill are being left with irreversible pulmonary fibrosis, involving major lung scarring. Italian doctors are finding three out of 10 seriously ill patients will have permanent lung damage.
Looking for clues
Virologists and infectious disease specialists say they don't understand fully the possible long-term health implications of COVID-19.
"We don't know yet, because we're still early in this infection, what may happen in those survivors from this infection," David Heymann, an infectious disease specialist, said last week during a briefing at Britain's non-profit Chatham House. "But it appears that some have had continued reactions in the lungs, that are continuing to keep them short of breath, and hopefully these will resolve but we just don't know yet whether they will."
Medical researchers say some clues about the long-term health implications may be gleaned from follow-up studies in Hong Kong into two other coronaviruses, SARS and MERS-CoV. One study into the long-term effects of SARS showed that 50 percent of survivors had much reduced physical capacity two years later compared to those who never became infected. And only 78 percent of SARS patients were able to return to work a year after the infection.
Another Hong Kong study found that 40 percent of people recovering from SARS still had chronic fatigue symptoms more than three years later.
For a subset of patients, chronic fatigue is only a small part of the problem. Infectious disease specialists in Europe, the United States and Asia say those who suffered severe symptoms and had to be hospitalized will be left with debilitating problems from the damage caused by the virus to major organs aside from the lungs.
Physicians say hospitalized patients experienced blood clots, causing strokes, heart attacks, renal failure and other complications, including brain damage, prompting lifelong health complications. This hasn't just been for older patients but for younger ones as well.
A study earlier this year that looked at Wuhan, the Chinese city where the coronavirus first emerged, found 12 percent of COVID-19 patients showed signs of cardiovascular damage. Other studies have found evidence of myocarditis, inflammation of the heart muscle.
And around 50 percent of patients diagnosed with SARS-CoV-2 experienced neurological problems. Physicians remain divided on how COVID-19 affects the brain and say more studies are needed. Last month, Robert Stevens, a professor of anesthesiology and critical care medicine at the Johns Hopkins Medicine in Baltimore, Maryland, said there are four possible ways the disease impacts the brain.
One "possibility is that the immune system goes into overdrive in an attempt to fight COVID-19, producing a 'maladaptive' inflammatory response that may cause much of the tissue and organ damage seen in this disease — perhaps more than the virus itself," he noted in a commentary. High fevers to low oxygen levels could also contribute to brain dysfunction and longer-term impairment. The brain is also impacted by strokes caused by blood clots.
Stevens and other doctors worry that "the virus may have the capacity to enter the brain and cause a severe and sudden infection." He said, "Cases reported in China and Japan found the virus's genetic material in spinal fluid, and a case in Florida found viral particles in brain cells. This might occur due to the virus entering the bloodstream or nerve endings."
Even after the pandemic, post-COVID patients are likely to remain a strain on public health systems, requiring an expansion of specialized rehabilitation.