COV-19: What is long Covid?

Why are so many people still experiencing symptoms more than 12 weeks after their original infection?

This syndrome has been referred to as long Covid, long-haul Covid, post-acute Covid, long-term effects of Covid or chronic Covid.

Early official estimates suggest it affects 10-20% of all those who have tested positive, however a third of all those who catch the virus report continuing symptoms after the acute phase and, with many silently managing it at home, those figures are likely to be underestimates.

The syndrome is established in the early stages of disease – researchers found that those who experienced more than 5 symptoms during the first week of infection were at greater risk of developing long Covid. In contrast, asymptomatic or mild disease is characterized by a robust immune response very early on in the infection. 

There is wide variety in how the syndrome is experienced between people: different symptoms, severity and health problems and for varying lengths of time. Most tests are unhelpful as they come back normal, so diagnosis needs to be made by excluding other conditions first. Many sufferers never even produced a positive PCR COV-19 test in the acute phase, possibly due to delay or insufficient viral load. While severity varies, daily activity function is significantly impaired in most, with many unable to perform even the simplest daily tasks such as showering and remembering words, never mind being able to work. 

Symptoms

Over 200 symptoms have so far been identified with long Covid. People experience different combinations of symptom clusters, so only a few of them may apply to you and the symptoms you have are likely to differ from those of someone else who also has long Covid. There is no difference in symptoms between age groups.

The most common long Covid symptoms have been found to be: 

·       Severe fatigue

·       Post-exertional malaise (exercise intolerance) - this is when you feel worse after physical and/or mental activity. It can be felt immediately or delayed.

·       Shortness of breath, difficulty breathing, heart palpitations, chest pain or tightness

·       Cognitive dysfunction, difficulty thinking or concentrating, problems with memory (‘brain fog’)

·       Pain, which may be felt anywhere in the body

Other reported symptoms include:

Abdominal pain, Diarrhoea, Nausea, Vomiting, Bloating, Food intolerances, Loss of taste/smell

Neurocognitive & mental health difficulties, Anxiety, Panic attacks, Insomnia, Depression, Hallucinations, Irritability

Cough, Sore throat, Low grade fever, Vertigo, Low blood pressure, Lightheadedness, Tinnitus

Blood clots, Irregular heartbeat, Tingling/ numbness, Metabolic disruption, Menstrual irregularities

Headaches, Migraines, Muscle pains/weakness, Runny nose, Sneezing, Sweating/freezing, Joint pain

Itching, Sudden redness, Rashes, Eczema, Psoriasis, Rosacea

The symptoms that you experience may also change over time. They are likely to be different between the acute and chronic stages.  After 6 months, researchers found that most were still ill but had experienced some improvement. The remaining symptoms were mostly systemic, e.g. poor temperature regulation, fatigue, post-exertional malaise and neurocognitive symptoms. After 12 months no significant difference was observed but there had been marginal improvement. By that time most sufferers had learned to manage their symptoms and remain optimistic in the belief they were getting better. However most were either unable to work or did so in a reduced capacity. 

Relapse

86% of those studied experienced relapses, primarily triggered by exercise, physical or mental activity and stress. At 12 months, only 7.7% were able to work without relapse (6% at 7 months) and 28% were not able to work at all. The impact not only on the individuals concerned and their families, but also on wider society is a significant source of concern.

Testing

While most tests come back normal and so are not helpful for diagnosis, these abnormal markers have been observed to indicate greater predisposition to develop chronic symptoms:

·       D-dimer (clot formation), IL-6 and CRP (inflammation) are elevated. Persistently elevated d-dimer is more relevant than CRP.

·       Low blood lymphocyte count (‘lymphopenia’)

·       Low vitamins C and D

In my next post I look at what might be causing long Covid.

Disclaimer: these COV-19 posts were written based on the evidence available at the time of writing. As new information continues to emerge, they may no longer be up to date or correct.