Fatigue, shortness of breath, muscle aches… progress on the elusive long covid trail

Long covid is the name given to a variety of symptoms that usually appear within three months after infection and persist for at least two months after infection with the SARS-CoV-2 virus, the most common of which are fatigue, shortness of breath, muscle aches and brain fog. While it is difficult to assess the number of people affected by this event, it would represent 10 to 20% of people infected with Covid, according to the World Health Organization (WHO).

Many teams around the world are still working on the mechanism, diagnosis or treatment of this phenomenon. Some recent work shows progress. A study published in January in the journal Science showed significant differences in blood proteins in more than 110 patients with Covid, including 40 patients with symptoms six months after initial infection. Onur Boymann, a Swiss researcher and lead author of the study, believes it is a “central piece of the puzzle” to explain why some people have Covid for so long.

Impact on “all aspects” of life

Part of the body’s immune system — the complement system, which normally fights infection by killing infected cells — apparently remains active, continuing to attack healthy targets and damage tissue, these researchers say. The team found that when people recovered from Covid for a longer period of time, this complement system also improved, according to Onur Boyman. “This shows that chronic Covid is a disease and it is possible to measure it,” added the researcher, raising hopes for the identification of specific markers.

For Lucia, a longtime Covid-19 resident of the United States who chose not to give her last name, “studies like this bring us a lot closer to understanding the disease.” Another recent study in patients with long-term Covid, published in Nature, found abnormalities in muscle tissue and dysfunction of mitochondria – the energy sources for the cell – which could explain the great fatigue of some.

Climbing the stairs to her apartment became an ordeal, says Lucia, who never imagined how Covid would permanently affect “all aspects of life, even social and financial” and how “distrust from the medical community or social circles or Denial” is sometimes added to health problems. The importance of support for patients is underlined by a study published this week in the British Medical Journal, which found that group rehabilitation improves the quality of life of patients suffering from post-Covid syndrome.

Elusive Cause “Multisystemic”

The protection of vaccines against Sars-CoV-2 against the long-term risk of Covid in adults and children has been confirmed by several recent studies. But, for now, long-term covid is still elusive because it is “multisystemic,” while “our brains are trained to think of diseases based on organ systems,” according to Ziad Al-Ali, a clinical epidemiologist at Washington University in St. Louis. . . The causes may also be associated, or succeed each other in the same person, or vary from person to person.

According to Ziad Al-Ali, understanding the mechanisms of prolonged covid may also help to understand “why and how acute infections cause chronic diseases”. This can thus strengthen the fight against other conditions, such as chronic fatigue syndrome or persistent symptoms after the flu. Especially “in the context of climate change”, “there is a risk of an increasing emergence of infectious pathologies, many of which will give rise to post-infectious syndromes”, warned, in November, Brigitte Autrain, president of Covars, an advisory body that advised the French government on long-term covid sent an opinion on