What are people dying of coronavirus dying from?
Q: “I would like to know precisely what people who die from coronavirus die from. As is sometimes the case with other viruses, this virus may cause complications, such as pneumonia, which can lead to death in people who are weak. Is this actually the case? Is it the same cause (for example, pneumonia) for all deaths, or can it be different depending on the person’s situation? ” asks François Lefebvre, from Quebec.
A call at first that 80% of people with Covid-19 have mild symptoms. For the rest of the patients, pulmonary complications occur first and sometimes require hospitalization. About 5% to 10% of patients require intensive care and respiratory assistance.
When the virus enters cells, it “hijacks” them to make them produce and assemble copies of the virus. Each cell can produce millions of these new “virions” before they burst and die. The destruction of cells lining the airways makes breathing more difficult. Cell debris and fluids accumulate and acute respiratory distress syndrome can occur. It’s the first thing.
But that’s not all. This destruction triggers a local immune response, which in turn has collateral effects and can worsen symptoms.
In particular, activated immune cells release large quantities of cytokines, substances that play many roles in defense against infection (there are around fifty cytokines). Some “attract” white blood cell reinforcements to the site of infection, others activate macrophages (cells responsible for “cleaning” intruders and debris), still others inhibit replication of viruses, etc. If the “dosage” is poorly controlled, the surge in the lungs of immune cells themselves overactivated worse.
It is probably this hyperinflammation that has killed many patients with Spanish influenza, and it is also observed in severe cases of COVID-19. We speak of a “cytokine storm” or a cytokine storm.
Worse, inflammation can spread throughout the body. May result in sepsis or even septic shock, which are associated with high mortality. These are complications related to an inflammatory reaction that becomes systemic in response to the infection (rather than being localized to the lungs). This syndrome causes a decrease in the oxygenation of the various organs, and can cause renal failure, liver disorders, and very serious hypotension.
The few studies detailing the causes of death of patients with COVID-19 indicate precisely that the coronavirus can play on all these tables.
A study published in The Lancet of 54 deaths in Wuhan reports that sepsis was the most common complication, followed by respiratory distress, heart failure and septic shock. Superinfection was also very common (50% of cases).
According to the same study, cardiac complications (heart failure, arrhythmia, myocardial infarction) were also more frequent in patients with severe pneumonia and 3% of patients who did not survive had cardiac arrest.
Why do some people have severe symptoms and not others? Aside from age and the existence of comorbidities, genetic factors may explain why the immune response is disproportionate in some people. Individual variations in the ACE2 receptor gene, the “gateway” through which the virus enters cells, for example, may explain why some people are more vulnerable, the researchers believe.
COVID-19 raises a lot of questions. In order to respond to as many people as possible, science journalists have decided to join forces. The media members of the National Cooperative of Independent Information ( Le Soleil, Le Droit, La Tribune, Le Nouvelliste, Le Quotidien and La Voix de l’Est ), Québec Science and the Déclic Center team up to answer your questions. . You have some? Write to us . This project is made possible thanks to a contribution from the Chief Scientist of Quebec , who invites you to follow him on Facebook , Twitter and Instagram .