DR ROBBIE HAMMOND
SNR CLINICAL FELLOW, INFECTIOUS DISEASES
ROYAL FREE NHS TRUST
Despite many bumps in the road, we appear to be coming out of the worst of the pandemic, new variants permitting. Certainly cases and hospitalisations could continue to rise, but the high vaccination levels of the vulnerable mean we are unlikely to see the death rates of previous waves.
This means we now need to confront the consequences of the last 18 months. Right at the top of our list should be a reckoning with the effects of ‘long Covid’. This term has been bandied around a lot in the media, but its meaning can be unclear.
Keeping the definition as straightforward as possible, it has been defined as persistent symptoms (of any type) post Covid infection, lasting for over 12 weeks. Some lag of symptoms after the initial infection is to be expected, but if this crosses over the 3 month mark – that is when we can start to use the ‘long Covid’ marker. How many people are currently in this category?
Well as with most aspects of long Covid, it’s uncertain. Imperial College’s REACT study estimated as many as 2 million of the population, whilst a study from the commonly used ZOE app estimated likely a tenth of that number. Either way, it is a large number of people, at least in the hundreds of thousands. So just what are these symptoms? As with any new disease, this is hard to define. Some are very commonly recognised, such as extreme tiredness, shortness of breath, chest pain and tightness, and insomnia. The total list can run into the hundreds, which reflects the difficulty deciding what stems from a post-Covid syndrome, and what is simply reflecting symptoms present in a general presentation. Even within ‘long Covid’, there seems to be two distinct categories.
Firstly, those who had a severe initial presentation of the disease, often requiring hospitalisation, and breathing support. Long-term damage and
scarring to their lungs leads to decreased ability to exercise, crippling fatigue, and chest pain.
There is a second group however, who may not have such a ‘severe’ initial presentation, although even without breathing difficulties, the fever and cough can be unpleasant. This group presents with symptoms quite common to other post-viral fatigue syndromes we have seen with other viruses such as Epstein-Barr virus (causing glandular fever) – with persistent fatigue, body aches, and mental health difficulties. It is hard to explain what is happening here, but it seems to relate to a hyperactive immune system – it is rare for traces of the virus to still be found. Over-stimulated by the virus, the body continues to produce chemicals called ‘cytokines’ which may be causing these persistent symptoms.
This is an uncertain part of the science currently, but a research group at the University of Cambridge have found a cytokine blood marker which may mark out long Covid patients. So what should you do if you recognise yourself in these above symptoms? If they are having a debilitating effect, do not suffer in silence, but get in contact with your GP.
The NHS is setting up Long Covid clinics all over the country, and attending these may both help you, but also our developing understanding of this new and unsettling condition.