Some Covid-19 patients are reporting that their recovery is taking longer than expected, as they experience shortness of breath and fatigue. Some have problems focusing, and headaches and dizziness, while others suffer anxiety and post-traumatic stress disorder.

Still, six months since the first case here, not much is known about these patients, and who is clearly at risk. "Anecdotally, many of my patients who I see in follow-up tell me that they feel tired and not quite able to do as much as they used to, but that they are gradually improving," says Professor Paul Tambyah, a senior consultant at the Division of Infectious Diseases at the National University Hospital (NUH).

"This is common with many viral infections, such as influenza and dengue, so I usually reassure them that this will generally gradually resolve over time."

He says there are large observational cohort studies being conducted in Singapore and elsewhere, but it is too early to know details about who gets these "lingering effects" and for how long.

Earlier this month, the United Kingdom launched a major study that will look into the long-term health effects of Covid-19 and aims to recruit around 10,000 patients discharged from hospital.

"In a completely unscientific way, about one or two of the 10 patients I saw (just in one day) in clinic in follow-ups had some mild residual fatigue, but only with strenuous exercise (like long runs)," says Prof Tambyah. These are the people with mild illness who have fatigue for a few weeks.

Then, there is another group - a small number of patients who have had strokes or other neurological complications and will need long-term rehabilitation and take longer to recover, he adds.

Dr Ooi Say Tat, who leads the Division of Infectious Diseases under the Department of General Medicine at Khoo Teck Puat Hospital, says doctors are still learning about syndromes of post-acute Covid-19 patients. "Of what we know, some patients developed heart attack, stroke, clots in lungs, weeks after initial infection."

One patient, Mr Toh Kai Kiat, had a cardiac arrest while he was on extracorporeal membrane oxygenation (ECMO) treatment, used as a last resort to save critically ill patients. He is still slowly recovering three months after being discharged from NUH.

Upon his discharge, he was given blood thinner medication to prevent blood clots, and still has follow-up checks for his heart, kidney and liver. Covid-19 may not just affect the lungs, but also the kidneys, liver, heart, brain and nervous system, skin and gastrointestinal tract.

NEEDS WALKING STICK

The 54-year-old now gets about with the aid of a walking stick, as he says the ECMO treatment had affected his legs.

"Initially, I was walking so slowly that I was slower than an elderly person," he says in Mandarin.

When crossing a road, he could only make it to the road divider before having to stop.

"Even the elderly gave up their seat for me at the kopitiam.

"But now, my appetite is good and I am slowly feeling better."

Dr Barnaby Young, consultant and head of the National Centre for Infectious Diseases (NCID) Research Clinic at the Infectious Disease Research and Training Office, says: "Most patients will be discharged well and are able to go back to exercise, work and their usual life.

"Some reported persistent mild respiratory symptoms such as cough or a delay in return of sense of smell, but this is infrequent."

Patients who had very severe infection and required long periods in the intensive care unit take longer to recover. This sometimes includes a prolonged period of rehabilitation, and is a consequence of any critical illness, says Dr Young.

"Slower recovery is mainly observed in those who have more severe infection, so older adults and individuals with comorbidities such as diabetes and hypertension are at greater risk, since they are likely to have more severe infection," he says.

Dr Young says there are also psychological consequences, which may reflect the fear and anxiety some experience after being diagnosed with Covid-19 and can manifest in unusual ways.

These symptoms can also be exacerbated by prolonged isolation, while rumours on social media and "fake news" can also cause problems, he says.

NEW TREATMENTS

Six months on, it is now also clear that managing inflammatory response cannot be ignored when treating a severely ill patient.

"We know now that the immune response to the disease may be just as important as the virus itself in causing some of the symptoms and signs of the infection," says Prof Tambyah. "This has resulted in exploration of drugs which modify the immune system being considered for treatment of patients with severe disease."

One example is the drug dexamethasone, he says.

"In NUH and in Singapore, we are involved in clinical trials of other agents which modify the body's immune response to ensure that an over active immune response does not cause more harm than good."

Dexamethasone was shown in a large clinical trial in the UK to benefit patients with moderate to severe disease. The corticosteroid, cheap and widely available, has been shown to reduce deaths among critically ill Covid-19 patients.

Before that, the anti-viral remdesivir had hogged headlines as the most promising drug. Studies showed it can reduce recovery time.

Dr Young says: "The major difference in how we approach patients today is knowing that we have two drugs: remdesivir and dexamethasone, which have been proven in clinical trials to be beneficial."

He adds: "These drugs are only used for patients who have, or are at risk of, severe infection."

Dr Young says the NCID continues to run clinical trials as part of global efforts to find better treatments.

"Oxygen support will be given if necessary and patients may be asked to lie in different positions, which helps improve lung function," he says.

The full spectrum of the illness ranges from asymptomatic disease to mild respiratory tract illness to severe pneumonia, acute respiratory distress syndrome, multi-organ failure and death.

Most patients here have mild infections, and are given symptomatic treatment and kept isolated until they are non-infectious.

Dr Young says: "We also now know that the virus can be detectable for prolonged periods in the nose - usually for weeks, but sometimes months. However, the virus is not infectious for that long and most illnesses will also recover long before this."

Importantly, the lessons learnt along the way would have helped to reduce poor outcomes.

Says Prof Tambyah: "We have also learnt a lot about the ICU care of these patients and worldwide. Death rates have dropped dramatically, suggesting that the lessons learnt are being applied globally."

These lessons, he says, include "proning patients (lying them prone), the use of high-flow oxygen, the use of dexamethasone, appropriate ventilation strategies, surveillance for risk of blood clots".