- Brian Owens, freelance journalist
- St. Stephen, NB, Canada
- brian.lawrence.owens{at}gmail.com
The global burden of the long covid has highlighted the neglected mystery of post-viral syndromes. Brian Owens asks what is changing
The long covid really shouldn’t have come as a surprise, says Vett Lloyd, a biologist at Mount Allison University in Sackville, Canada. “When the pandemic started, the general assumption was that there were two possible outcomes for an infection: you would either get better or you would die,” he says.
But there is a third possible outcome. A number of disease-causing pathogens (some viral and some bacterial) have long been known to be associated with post-infection symptoms in a significant minority of patients.
“There was no real reason to think that SARS-CoV-2 should be different from the original SARS, which also caused post-infection syndromes,” says Lloyd. He is one of many researchers who hope that the attention and funding directed toward a long covid will help figure out how and why other infections can cause persistent and sometimes debilitating symptoms.
Common symptoms
The list of infectious diseases associated with long-term symptoms includes Ebola, West Nile virus, polio, and Lyme disease. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is also believed to be a postviral syndrome.
Although these diseases all have different acute symptoms, the symptoms associated with post-infection syndromes are often remarkably similar: fatigue, neurological impairments, muscle and joint pain, sleep disturbances and irritability are common, says Andrew Lloyd, a disease infectious doctor at the University of New South Wales in Sydney, Australia (and no relation to Vett Lloyd), although each acute infection tends to add its own specific “flavor” or symptom.
Andrew Lloyd led the 2006 “Dubbo” study,1 which found that about 12% of people infected with infectious mononucleosis (glandular fever), Ross River virus or Q fever in the Australian rural township of Dubbo still had symptoms after six months. He says symptoms after glandular fever often include a sore throat, while in Ross River joint pain from the virus is dominant and Q fever leads to sweats and headaches. “The post-infection phenomenon seems to involve a common denominator, with variations on the theme,” he says.
And doctors often don’t take post-infection syndromes seriously, at least at first, something Vett Lloyd knows. His main area of study is Lyme disease, and post-treatment Lyme disease syndrome (or chronic Lyme) is still a controversial topic in many medical circles. The same thing happened with the long covid, but that changed soon.
“There was a tremendous response from the medical community,” he says. “It went from ‘this is all in your head’ to ‘this is real’ to dedicated clinics, the fastest I’ve seen for any post-infection syndrome.”
This was due, at least in part, to the large number of people affected, with some studies suggesting that up to half of all covid-19 infections may lead to persistent symptoms.23 Andrew Lloyd expects that the actual prevalence of covid-19 be more like 10. -15%.
Unanswered questions
Finding a common cause for the various syndromes would be a breakthrough in postviral syndrome research.
Several hypotheses have been proposed, including persistent but undetected infections, autoimmune responses, dysregulation of the microbiome, and tissue damage.4 But Andrew Lloyd of the University of New South Wales largely dismisses these ideas. “The lessons we’ve learned from other post-infection syndromes is that it’s not a persistent infection, not an immunological one, not a simple psychological disorder,” he says.
Among researchers studying these diseases, including long covid, the smart money is now on some sort of central nervous system disorder,5 he explains. And since there is no clear evidence of any major structural problems in the brain, this suggests that the disorder is at the cellular and protein level.
“There is circumstantial evidence to support that,” he says. “But nothing concrete yet.”
treatments
Alba Azola, co-director of the Post-Acute Covid-19 team at the Johns Hopkins University School of Medicine in Baltimore, USA, has been treating patients with persistent symptoms of covid-19 since April 2020.
At first, patients with long covid appeared to have a lot in common with people with postural orthostatic tachycardia syndrome (POTS), a blood circulation disorder characterized by an elevated heart rate and other symptoms triggered by standing, as fatigue and brain fog are also common symptoms of this condition. So Azola, a physical therapist and rehabilitator, along with a team of physical therapists, began treating these patients with the same protocols as for POTS, focusing on things like diet and exercise.
But after about three months, it became clear that this exercise-focused treatment regimen wasn’t working. The team realized that long covid was more like ME/CFS, Azola says, and started building on ideas from that area. That meant focusing on managing and conserving energy levels and understanding what triggers can lead to fatigue, to get off what she calls the “corona-coaster,” where patients start feeling better, become more active, and then crashes
He says that in the absence of a reliable treatment or cure, patients must learn to live with the disease by being selective with their energy and what they invest it in, which can be as simple as using a shower chair to avoid – it unnecessary effort “I learned all of this from the ME/CFS community,” he says.
The long covid causes investment, finally
Because post-acute conditions have been neglected for years, the medical field is far behind in finding effective treatments, but Azola hopes the focus on long-term covid will help shed light on other related illnesses.
In some places this is already starting to happen. The Canadian province of Quebec recently announced it would provide C$20.5 million (£13.5 million; €15.6 million; US$15.6 million) to open 15 clinics focusing on both long covid as in Lyme disease. The clinics, which will open in the fall of 2022, will bring together different specialists to help coordinate the treatments of these complicated conditions, in the type of multidisciplinary teams that Azola advocates. The American Academy of Physical Medicine and Rehabilitation has also launched a multidisciplinary team to develop clinical guidelines and educational resources for physicians.
Vett Lloyd also sees the Quebec clinics as an important step in getting to the bottom of the whole range of post-infection syndromes. “It’s horrible that it takes the suffering of so many people with long covid to make this happen, but integrated clinics like these will help people with many post-infection syndromes,” he says.
Andrew Lloyd agrees. “Billions of dollars have been invested in long-term covid research,” he says. “With any luck we will find something relevant not only to long covid but also to other post-infectious syndromes.”
Footnotes
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Competing interests: I have read and understand the BMJ’s declaration of interests policy and have no relevant interests to declare.
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Provenance and peer review: Assignment; externally peer reviewed.
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