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The ‘huge health burden’ of a little understood condition

Already, thousands of New Zealanders are believed to have been affected by long Covid. Some are worried about the implications of that number blowing out in an outbreak of the Omicron variant. Katie Kenny reports.

In Aotearoa New Zealand, and worldwide, the main metrics of the coronavirus pandemic have been case numbers, hospital admissions and deaths. But there is another, more elusive and less well-understood statistic that gets less attention.

International data suggests between 10 and 30 per cent of all Covid-19 cases experience long-term symptoms such as fatigue, shortness of breath, and cognitive dysfunction. It’s estimated as many as 100 million people worldwide already suffer from the post-viral illness.

In New Zealand, where there have been 15,000 confirmed cases and 52 deaths, up to 4500 people could be affected by long Covid.

What is long Covid?

In June 2020, The Atlantic reported on Covid19 ‘‘long-haulers’’: previously young, fit and healthy people who were enduring relentless waves of debilitating symptoms months after testing positive for the virus.

At the time, they said they felt left out of the narrative and excluded from the figures that define the pandemic. Many of them faced disbelief from friends and medical professionals.

More than 200 symptoms have been reported to be associated with long Covid, and although it’s classified as a single condition it can affect multiple body systems, such as respiratory, cardiovascular, neurological, gastrointestinal and musculoskeletal systems.

‘‘Sars-CoV-2 is often described as ‘just’ a respiratory virus, but really, the upper airways and lungs are the gateway,’’ says Dr Anna Brooks, a senior lecturer and immunologist at Auckland University. ‘‘Once the virus gets there, it can cruise off and wreak havoc everywhere. The progression can vary so much, person to person. And anyone is susceptible.’’

The World Health Organisation says symptoms typically start within three months from the onset of Covid-19, can last for at least two months, and can’t be explained by an alternative diagnosis.

Otago University Emeritus Professor Warren Tate is a biochemist who has been studying myalgic encephalomyelitis (ME), also known as chronic fatigue syndrome (CFS) for more than 30 years.

In 2020, his team proved that ME/CFS is not psychosomatic but has a biological basis. The research identified changes in important physiological and biochemical pathways and systems in affected patients when compared with healthy people.

Tate is now collaborating with Brooks to study long Covid and post-viral illnesses more comprehensively.

Both have been working with the team led by Resia Pretorius, a professor of physiological sciences at Stellenbosch University in South Africa, whose lab has found significant microclot formation in the blood of long Covid patients.

In a recent article for The Guardian, Pretorius wrote: ‘‘Since early 2020, we and other researchers have pointed out that acute Covid-19 is not only a lung disease, but actually significantly affects the vascular (blood flow) and coagulation (blood clotting) systems.’’

In blood from patients with long Covid, her lab found persistent clots that were resistant to the body’s own agents that would usually break them down. Essentially, they result in a lack of oxygen in tissues to sustain bodily functions, known as cellular hypoxia. This could be what causes the numerous reported debilitating symptoms of long Covid.

The struggle to diagnose

While Brooks is working with international colleagues to develop a clinical test – and possible treatments – there is currently nothing readily available to diagnose long Covid.

It is thought that most people who have the condition aren’t seeking medical help. And those who do are often dismissed by their doctors.

‘‘If you have these confusing and difficult to describe symptoms and your doctors say they’re all in your head, that’s going to cause more harm,’’ Brooks says.

Longer-term symptoms such as fatigue are to be expected following any severe infection and prolonged hospital stays, says Professor Peter McIntyre, an Otago University paediatrician specialising in infectious disease. And among people managed in the community, it’s much more challenging to tease out persistent effects of Covid from symptoms or problems due to other causes.

One English study used a primary care database with 80 million records to identify more than 100,000 people with Covid and match them, by age and previously documented health problems, with the same number of people with influenza without Covid.

It found between three and six months after diagnosis, 42 per cent of those with Covid had one or more persistent symptoms, compared to 30 per cent of those with influenza, with significantly higher proportions of anxiety, depression, breathing difficulties and cognitive impairment.

Kurt Krause, a professor of biochemistry at Otago University and a Fellow of the Infectious Diseases Society of America, hopes the focus on long Covid will lead to increased funding and awareness for postviral illnesses generally.

He says while some post-viral complications are obvious and easy to document (if HIV is not treated, for example, it can target and weaken the immune system, leading to Aids), others are harder to quantify.

‘‘If you have these confusing and difficult to describe symptoms and your doctors say they’re all in your head, that’s going to cause more harm.’’ Dr Anna Brooks, right

‘‘These are more functional complaints: inability to concentrate, low energy, brain fog. We’ve seen these symptoms for decades, but I can’t draw blood to confirm them.’’

Thanks to research done on ME/CFS, it is well-established that functional complaints are ‘‘real’’, and work is being done to figure out causes and treatments.

‘‘In previous conditions like this, there was always this initial struggle that people who were suffering were dismissed. I’m hoping we’ll be wise enough [this time] to realise people could very well be having long-term effects from Covid. And then do our best to take care of those people.’’

The struggle to understand long Covid is also not helped by the lack of formal surveillance – there is still no country in the world doing this.

‘‘If you’re not tracing, then you can’t see the scale of the problem,’’ Brooks says.

New Zealand, given its relatively manageable number of cases, is in a unique position to lead the world in having a long Covid registry, she says.

At the time of publication, the Ministry of Health had not responded to questions about tracking the number of Kiwis experiencing long-term symptoms of Covid.

In August, the ministry awarded Victoria University of Wellington a contract to carry out a study into the impacts of Covid domestically. The study, which has a particular focus on Ma¯ ori and Pacific people, as well as people with disabilities, will inform how health services can better meet the needs of people with Covid. But results won’t be available for a year.

Who gets it, and how to avoid it

It’s difficult to work out the chance of getting long Covid from many of the studies done so far because they have involved people requiring hospital-level care for a wide range of problems relating to multiple organs.

Enough is known, however, to say that long-term symptoms are more likely among older people and those who have required hospital care.

But this doesn’t mean young people are spared. In a cohort of more than 300 healthcare workers in China with severe Covid and a median age of 36 years, one year on nearly a third had persistent symptoms including a decline in muscular strength, flexibly, agility and balance. Similar results have been reported in a study of young, Swiss soldiers.

Those most at risk are the unvaccinated, McIntyre says. ‘‘It’s clear that unvaccinated people who get severely ill from Covid can take a very long time to recover, may not ever recover fully, and among those who end up in intensive care are quite likely to die early even if they leave ICU.’’

While good data about Omicron and long Covid is hard to find, ‘‘my strong suspicion from what we do know is that people who are fully vaccinated, especially with a booster, will have a low risk of anything more than a cold’’.

Professor Stuart Dalziel, a paediatrician with sub-specialty training in paediatric emergency medicine, hopes a focus on long Covid will also shed light on how post-viral illnesses can affect children and young people.

‘‘If a child came into hospital with a runny nose, we never tested for a virus. Now, with every child in hospital we’re testing for Covid. So we’ve got something to link symptoms back to. But that sort of information hasn’t been collected in a robust way for childhood infections.’’

‘‘If long Covid is associated with this new variant, there’s going to be a huge health burden.’’ Warren Tate, left Otago University Emeritus Professor

What Omicron has to do with it

So far, there is nothing to suggest the burden of long Covid will be lower with Omicron cases, despite the variant being described as milder. Experts are concerned this description is leading people to underestimate the danger of long Covid, particularly if they’re unvaccinated.

‘‘My colleagues in the United States and elsewhere say it’s still too early to say,’’ Brooks says. ‘‘But there’s no-one out there who feels Omicron will spare us. The scale of infections we’re seeing already gives cause for alarm.’’

Her recommendation? Get a booster shot. And follow other public health measures.

‘‘[Long Covid] should have been at the forefront of our vaccine campaigns.’’

In the meantime, Tate, Brooks and others worry that with the increased transmissibility of Omicron, it is possible more people overall will be affected by long Covid than with previous variants of the virus.

‘‘If long Covid is associated with this new variant, there’s going to be a huge health burden,’’ Tate says. ‘‘We just don’t know.’’

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2022-01-16T08:00:00.0000000Z

2022-01-16T08:00:00.0000000Z

https://fairfaxmedia.pressreader.com/article/281629603634669

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