The Long and the Short of it

One of our sons (D) and his partner (L) had covid-19 at the start of the pandemic in March 2020. They both had the standard covid symptoms but there were no available tests to confirm the diagnosis at that time. D was off-colour for all of three days with symptoms no worse than a cold,  whereas L, our de facto daughter-in-law, has been laid low for over a year and is still suffering the debilitating consequences.

Like L, many long-covid sufferers have not had a positive test for SARS-CoV-2 virus or for antibodies against it, either because tests were not available when they were ill or because  the antibody tests they had were not sensitive enough (a problem with several of the early tests). 

Broadly speaking, there are three types of long-covid symptoms: 

1. The first type is characterised by “exercise intolerance”, whereby the sufferers have little stamina and get exhausted from even the smallest tasks involving physical activity.
2. The second type involves cognitive disturbances, such as a sensation of ‘brain fog’ and memory problems. 
3. The third type affects the autonomic nervous system, which controls things like heartbeat, breathing and digestion. Patients in this group can experience heart palpitations and dizziness for example.

L has endured an extreme case of type 1 symptoms, as well as some symptoms of type 2. There are some first-hand accounts from sufferers in this Royal Society video.

Medical researchers are exploring three possible biological explanations:

Hypothesis 1. Long covid is a lingering viral infection which can hide out of reach of the immune system (like malaria, chickenpox and HIV), perhaps producing some active viral proteins not detectable by PCR and other antigen tests.

Hypothesis 2. It is an auto-immune disorder. There is strong evidence of cases of an over-reaction of the immune system in the acute stage of covid when many patients died from so-called cytokine storms

Hypothesis 3. It is due to tissue damage caused by inflammation during the initial acute stage, damage for example to the lining of blood vessels restricting blood flow to the brain.

To date there have been almost 4.5m confirmed cases of covid-19 in the United Kingdom and in reality probably many more. The Zoe Covid Symptom Study based in King’s College London found that 1 in 50 covid sufferers still had symptoms 12 weeks or more after the acute phase. This means that getting on for 100,000 UK citizens have post-covid-19 syndrome, and that many of them will need long-term treatment and possibly be unable to work. These cases will place a significant burden on the economy and the medical services over and above the existing negative impacts of the acute covid-19 cases. For this reason, there is hope that more research funding will be channelled towards research into long-covid in particular and post-viral illnesses in general, attracting more medical scientists to direct their efforts to understanding these conditions and finding treatments. That could bring relief and credibility to the many others who have found themselves languishing in similar ways after other viral or bacterial infections. “It’s an ill wind …”

(This blog post is informed by an excellent three-page article entitled “Post-covid syndrome — The sting in the tail” published in the print edition of The Economist on 1st May 2021, page 69.)