Early research into Covid-19 patients in Wuhan, China has found that 17 per cent of those infected developed acute respiratory distress syndrome.
Among this group, 11 per cent saw their condition worsened in a short period of time and ended up dying of multiple organ failure.
It was also discovered that many of those who succumbed to the latest novel coronavirus had underlying health conditions or were over age 60.
While plenty of stories have emerged tracking the spread of the virus worldwide, relatively little has been said about how the virus interacts with the human body, and how it can lead to severe consequences and even fatalities.
One reason could be because scientists are still figuring out how the virus works.
But here is what doctors in Canada know so far.
What does the Covid-19 virus do?
After the Covid-19 virus enters the body through droplets in the air, it appears to attach to a particular receptor found in lung tissue.
The virus then makes more copies of itself once it “hijacks” the host cell’s mechanisms.
Tissue damage happens as a result of viruses taking over the cell completely.
This causes the cell to die.
The lung cannot function effectively if large numbers of cells die.
So the Covid-19 virus leads to cell death?
There is another way cell death occurs.
It happens when immune cells mount a defence against the viral infection.
Immune system in healthy people causes havoc as a result of Covid-19?
Those with severe cases of Covid-19 are experiencing a clinical phenomenon known as a “cytokine storm”.
The term describes an overproduction of immune cells and their activating compounds, known as cytokines.
A surge of activated immune cells can enter the lungs.
This becomes too much of a good thing.
When the immune system overacts to the infection, the strength of the immune response can put a healthy person at risk for complications associated with respiratory illness.
This would see the immune system causing damage to the lungs rather than the virus itself.
A cytokine storm is also consistent with the disease that SARS caused previously.
It is also consistent with what is seen in people who are severely ill with influenza virus infections.
To reiterate: Cytokines are proteins used by the immune system as alarm beacons.
Cytokines recruit immune cells to the site of infection to kill off the infected tissue in a bid to save the rest of the body.
Humans rely on our immune systems but during a runaway coronavirus infection, when the immune system dumps cytokines into the lungs without any regulation, this culling becomes a free-for-all.
How is the novel coronavirus Covid-19 different from other coronaviruses?
The coronavirus causes respiratory infections.
Humans are infected every year by the common coronaviruses, which usually cause mild, uncomplicated upper respiratory infection.
But Covid-19 can cause acute respiratory distress.
This means that the patient’s lungs can accumulate fluid, which is more typical of pneumonias.
It’s respiratory failure or cardio-respiratory issues that lead to death.
The Covid-19 viral infection can cause lungs to be flooded with fluids?
As the site of gas exchange, lungs experience a lot of blood flow in them
Airways have to be relatively dry so that a healthy person can breathe in air, which gets transferred to red bloods cells and carried to the rest of the body.
But during infections or immune responses, the tissue becomes damaged.
Fluid that’s normally contained in the blood vessels starts to leak into airways.
That build-up of fluid in lungs is what can cause breathing distress, because the lungs are not exchanging gas very efficiently.
Cytokine storms can have other effects on the lungs, such as inflammation.
Kidney failure might also occur, and the stomach and liver might be impacted as well.
For a more in-dept read on how the Covid-19 virus can impact the rest of the body, National Geographic has written a detailed article on what happens to the human body beyond the lungs when the novel coronavirus attacks.
Top photo via Pixabay