In the early months of the pandemic, the idea that some people might develop a chronic condition after coronavirus infection didn’t seem important, in the urgency of trying to save lives. Over time, however, the long covid (with its most common symptoms such as chronic fatigue, shortness of breath, muscle aches, dry cough, headache, cognitive difficulties) has taken on more defined contours and has been recognized as a highly debilitating syndrome: not only does not contract covid in a severe form count, it would be preferable to avoid getting sick completely, because SARS-CoV-2 has an unpredictable impact on the human immune system and not yet fully understood.
Now that funds and staff are focused on the long covid and its treatment, here are four questions we should answer as quickly as possible:
- how many people contract long covid and who is considered most at risk?
- long covid: what exactly does it depend on?
- what is the relationship between long covid and other post viral syndromes?
- how to help people suffering from long covid?
1) How many people contract long covid and who is considered most at risk?
The first “censuses” of patients with long covid focused on people hospitalized, who very often report at least one symptom of the infection even after several months of recovery. But since most covid sufferers do not require hospitalization, the most accurate way to understand the prevalence of long covid is to track anyone who has received a positive swab over time. The most accurate analysis was published by the UK’s National Statistics Office (ONS) which followed 20,000 people who tested positive until April 2021: 13.7% of them still reported symptoms 12 weeks after the test.
In practice, more than one in 10 people who recovered from covid end up dragging the long covid for months. If we extend the conclusions of the English study to the rest of the world, it would mean having over 16 million people with long covids waiting for treatment. As explained on Nature, this condition mainly affects women, although it is men who are most often at risk of becoming ill with severe covid. Another ONS study found that 23% of women with covid still have symptoms after 5 weeks, compared with 19% of men.
Long covid also seems to affect middle-aged people more frequently: again according to the ONS, 5 weeks after diagnosis, the prevalence of the syndrome is 25.6% between 35 and 49 years, while it is less common (but not infrequent) in younger and older people. 9.8% of children between 2 and 11 years old still show symptoms 5 weeks after the positive swab.
2) Long covid: what exactly does it depend on?
Studies on the biology of the long covid are complicated by one primary question: it is a multisystem disease, that is, it affects various organs. Not only that: under the expression long covid fall different “families” of disorders (that is, there is no single type of long covid). It is unlikely that the virus, in these patients, is still at work – the body cleans itself of SARS-CoV-2 in a few weeks – however some viral fragments could remain in circulation longer, even for months, and continue to confuse the immune system even if they no longer infect the cells.
The long covid could be the consequence of an autoimmune reaction, in which an initial exaggerated activation of the immune system ends up turning against the organs and tissues of the organism itself rather than against viruses. Periodic monitoring of the blood and saliva of patients who suffer from it revealed altered levels of cytokines (the molecules that help regulate the immune response) in the blood, as well as some proteins that indicate neuronal dysfunction.
Speaking of cognitive relapses, an analysis by the English PHOSP-COVID study, which tracked the symptoms of 1,077 long covid patients, identified four groups of patients with different symptoms: three of them had physical and health difficulties. mental (anxiety) but no cognitive impairment, while a fourth group showed mild physical symptoms, moderate mental health changes but important cognitive difficulties with memory and language. Cognitive disturbances appear to manifest themselves separately from the remaining symptoms, a rather unexpected finding.
3) What is the relationship between long covid and other post viral syndromes?
It is not at all unusual for an infection to cause lasting aftermath even after official recovery. Fatigue, musculoskeletal pains, cognitive difficulties and mood disorders were found, six months after diagnosis, in 12% of people with bacterial or viral diseases, in a study of 253 patients: a very similar percentage. to that of prevalence of long covid.
There appear to be important similarities between long covid and chronic fatigue syndrome, CFS or myalgic encephalomyelitis, a long-term condition involving symptoms such as extreme fatigue not relieved by rest, chronic pain, mental confusion, sleep and memory difficulties, and which often occurs after a viral infection, it is not clear whether due to the pathogen itself (possibly the Epstein-Barr virus, responsible for mononucleosis) or an excessive response of the immune system.
However, the fact that long covid is not a unique and well-defined syndrome complicates the comparison. Researchers (such as those in the DecodeME study) are trying to recruit 20,000 patients to identify the genetic factors that contribute to CFS, and a comparison will then be made with those found for long covid.
4) How to help people suffering from long covid?
There is still no real treatment against long covid, but fortunately the first rehabilitation programs for these patients are starting (the UK national health system has financed 69 clinics with the equivalent of 11.6 million euros across the country, to help those suffering from this condition). Multidisciplinary teams are needed, because there are patients who also suffer from 16, 17 different symptoms, and the will to recognize long covid is needed. like a disability: Patients must rest for several months.
Clinical trials are testing the effects of anti-inflammatory, anti-fibrotic (that is, anti-scar tissue formation) and anticoagulant drugs, both on patients already with long-covid, and on people hospitalized for covid or in quarantine with mild symptoms. in your own home: a possible approach could in fact be attempt to prevent long covid while the disease is still ongoing, rather than treating it after its appearance.
The effects of vaccines on the long covid are also being studied. In fact, many patients with this condition report feeling better after vaccination, perhaps because the vaccine erases the residual traces of the virus in the body, or because it helps to put the immune system back on track.