Long Covid: what we know about it and how best to treat it

Much has been written about long Covid. Sufferers describe troubling ongoing symptoms on social media that persist for weeks after infection. Meanwhile, research to find a cause continues and multiple theories have emerged.

So what do we now know about long Covid, the risk of getting it and how best to treat it? Guardian Australia spoke to the leading physicians working with long Covid patients, including in long Covid and post-Covid clinics, to better understand the latest evidence.

People are often reassured by the multidisciplinary approach of the clinic and when they hear most patients improve over time and recover, she says.

Rees says people admitted to hospital with Covid-19 sometimes received corticosteroids and symptoms of this can include anxiety and poor sleep. Being on machines and a longterm stay in in intensive care can also leave people with fatigue and muscle weakness. Sometimes ongoing symptoms are due to the toll on the body of being in hospital rather than being due to long Covid, she says.

This correct diagnosis is important because if a different condition is causing the symptoms, it might be treatable in a different way.

Being vaccinated and boosted seems to protect against long Covid. Estimates of those with Covid who will develop long Covid range from 5% to 30%, but applying this prevalence to the general population is problematic.

Not all long Covid studies are well designed, with a control group. A control group comprises people who are similar to the participants being studied, except they do not have the condition in question.

Dr Kate Gregorevic, a geriatrician and internal medicine physician, says this control group is really important when looking at common long Covid symptoms such as fatigue, which is present in about 20% of the population anyway. By comparing the long Covid group with a control group, you can see if a symptom really is more common after Covid than would be expected in the general population.

Some long Covid studies also use a large range of symptoms, from fatigue to gastrointestinal disturbance, shortness of breath and brain fog. These symptoms also range in severity, and Gregorevic says this lack of specificity will identify more people to study, but depending on the way the study is designed, this larger size does not always mean the study findings are stronger or that all of those participants have symptoms caused by long Covid.

Sometimes studies ask participants to self-report their symptoms and while these studies can be useful, they can also have strong limitations, with questions around bias and validity.

Prof Gail Matthews from the Kirby Institute is a lead investigator on the Adapt study examining patients for long Covid, which has been running since mid 2020.

In research from the study published in January, her team examined blood samples from people with and without long Covid. They found some participants with symptoms eight months after a Covid-19 infection had elevated levels of types of proteins that cells make in response to the presence of a virus.

These proteins generally disappear after an infection clears, but in patients with long Covid, the proteins were still present. The cause of this requires further study.

The study involved 62 participants, including 31 control participants without long Covid. The study authors said the results now require validation in other long Covid cohorts.

Matthews says it is not possible to come up with a strong estimate of prevalence from studies conducted to date, including her own.

However, even a small percentage of people with Covid-19 developing long Covid will lead to significant numbers of people affected, given the high overall Covid-19 case numbers in the community. While the majority of these people will recover, this can take months or in very rare cases, years.

There are two Covid clinics at Royal Melbourne hospital: one that assesses people and rules out alternative explanations, and an allied health rehabilitation program focused more on therapies, exercise physiology, diet, psychology and even treatments such as singing therapy to help people to use their voice and strengthen their lungs.

A difficulty with treatment is the cause of long Covid is still being studied. There may be different causes for different people. Some theories about the trigger include immune system activation, ongoing inflammation and other abnormalities including in the lungs.

He says this is similar to how now disproven treatments like ivermectin and hydroxychloroquine were initially being heavily promoted as cures for Covid-19 early on in the pandemic, when little was known about how to care for patients.

The good news is, many others with long Covid manage and improve with an individualised program that fits within their needs and with what they can do.

Faux says the demographics and symptoms of those presenting with long Covid also differ by country, for reasons still being studied. In his clinic, he is also seeing high rates of people with pre-existing mental health conditions that are exacerbated after Covid-19 infection.