Among the current generation of kids, many are growing up with their mother or father confined to bed or confined to bed themselves. According to a study by ANU, long COVID is hitting up to an estimated 20% of Australians three months after they contracted COVID — mostly women, but also men and children. In the current COVID wave, that means a lot of people coming down sick for a long time.
Long COVID is keeping people from their jobs and their lives, and as COVID cases continue, it is unclear whether the rate of new long COVID cases is increasing faster than the old cases recover.
The result of infection is lasting symptoms. The result of lasting symptoms: suffering. As the report of the committee into long COVID says, long COVID causes “lost earnings, impacts on household finances, and, in some cases, an inability to work or to extend care to family members including children”.
The effect can be seen clearly in the US where disability has risen very quickly since 2020 amid low vaccination rates and rampant infectious spread.
The pattern is less visible in Australian data, as the next chart shows. Here, the share of people claiming to be unable to work thanks to disability is affected a lot by changes in the relative rates of the JobSeeker payment and the disability support pension.
But we see a general uptrend in people who are unable to work because of disability, which is not what we would expect in a time of low unemployment. The signal is particularly strong in people aged 35-44 — prime working years.
A recent study published in The Medical Journal of Australia suggested that the cost of the lost labour from a single round of infections in 2022 would be $9.6 billion and that hundreds of thousands of Australians would be affected.
We need to be clear about what long COVID is and how long it lasts. The disease is under-researched and the clinical course is still being discovered as time passes, but it is possible to say the following.
We can divide long COVID into a few groups. There are people with damaged lungs from serious disease and people with lingering coughs; that’s one group. Then there are people whose sense of smell takes a while to come back. That’s another group.
Then there’s the most important group: the group with mysterious lingering symptoms, even if they didn’t have a bad case of COVID in the first place. This is the group that’s been a mystery to science, and the group where we find people who don’t recover.
This group overlaps with the disease known as chronic fatigue syndrome (CFS), aka myalgic encephalomyelitis (ME): a mysterious post-infection condition that debilitates people — mostly women — and produces symptoms in a range of areas; neurological, blood pressure, pain, immune system, etc.
How common is long COVID? Well, there are all sorts of estimates, ranging from 0.09% to one in five, according to the NSW Agency for Clinical Innovation. It depends in part on how you define long COVID and when you ask about symptoms. If a cough four weeks after infection onset counts, long COVID is common; if you need to be severely debilitated 12 months later, long COVID is less common.
What seems to be true is that many people get better. Online forums devoted to long COVID are full of recovery stories — some spontaneous, others attributed to various actions the person took. Science is silent on what might lead to recovery, although many trials are underway.
Those same forums are also full of the stories of people who have not gotten better, and many who have gotten worse over time. The odds of spontaneous recovery for a person seem to worsen as their illness progresses. Many people have long COVID for less than six months, some for a year, some for a few years, and an unlucky group keep suffering for a longer time.
Obviously there are no cases of long COVID in the world that have lasted more than five years: five years ago the virus was almost exclusively infecting pangolins, or maybe bats. But the history of ME/CFS suggests that some people can be sick for decades.
Long COVID was most commonly caused by the delta virus. The more recent omicron virus can still cause long COVID, but does so less often. This is consistent with the finding that less severe illness is less likely to cause long COVID. Vaccination also appears to reduce the odds of getting long COVID.
The Burnet Institute is one of the leading Australian organisations studying long COVID. Its recent study argues that long COVID is caused by viruses persisting in the body. This is one of the two basic theories, the other being the “hit-and-run” theory, where the virus is gone but some key system, probably immunological in nature, is disturbed.
The Burnet Institute’s argument of viral persistence has some support. A French team has recently teased some brand new findings — as yet unpublished — saying they know where the virus has been hiding. The research group, from the French National Centre for Scientific Research, have found SARS-nCov-2 hiding in a special type of immune cell called megakaryocytes. These cells produce the little clotting factors in blood called platelets and — the French team says — can seed the virus into the platelets. If that leads to problems with blood flow, it could explain many of the problems in long COVID, including fatigue and brain fog.
There’s certainly precedent for a virus to hang around in immune cells after an acute infection. That’s what the human immune virus (HIV) does, infecting T-cells. It causes an even more dangerous post-infectious immune condition, known as AIDS, which is fatal if the infection is not kept in check by anti-viral drugs.
The big difference between long COVID and AIDS is that long COVID is not infectious after the acute infection. In that sense, the post-infectious period is more akin to the situation with polio where after an acute illness, a small proportion of sufferers go on to experience long-lasting symptoms. In the case of polio, the virus attacks nerves, causing post-polio syndrome.
The idea that infections can cause illness after their acute phase has been unfashionable until recently. While HIV/AIDS is well-understood, it has been considered an unusual case. People were thought to beat infections and move on. That way of thinking is being upturned by some large and powerful studies into the causes of chronic disease.
Several other viruses also seem to be implicated in the emergence of “other” diseases. Human papillomavirus is an obvious trigger for the emergence of cervical cancer. Most famously, the Epstein-Barr virus was revealed as a necessary trigger for the emergence of multiple sclerosis. That revelation came from an extremely strong study of 10 million members of the US armed forces and has been revolutionary.
And of course, two Australians won the Nobel Prize for proving that stomach ulcers were caused by bacteria rather than manifested by stress.
If long COVID is shown to be caused by viral persistence, then the techniques that have fought back against viruses in other conditions could be deployed again in this condition. That would be a vital step to getting a lot of people, both children and their parents, out of a miasma of suffering and back into life.
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