Here’s how the new virus attacks the cells of our body by damaging the lungs and other organs and how it causes breathing problems. X-rays do not always show the disease.
For most patients of COVID-19 starts and ends in the lungs, because, like the flu o coronaviruses is a respiratory diseases. They typically spread through the cough and sneezing of infected people, through the micro drops that can transmit the virus to subjects who are in close contact. Coronavirus also manifest themselves with symptoms similar to those typical of the flu, that is why the two diseases can be confused: patients may initially have fever and cough, which then progress to becoming interstitial pneumonia.
How Does This Coronavirus Cause Infection?
The virus spreads through droplets spread in the air by coughing or sneezing from infected people who, who is close, can absorb through the nose, mouth or eyes. The viral particles in these droplets travel quickly to the back of the nose and to the mucous membranes inside the throat, attaching themselves to a particular receptor in the cells.
The new coronavirus has many tips reminiscent of those of crowns. The tips are made up of “peplomers” protein structures which together with other mechanisms serve to attack the virus in the cells of the organism to be infected. Once the viruses attach to the host cells, they release their genetic code by changing the behavior of the cell.
How Does This Process Cause Breathing Problems?
Copies of the virus multiply, explode and infect nearby cells. The first symptoms often start from the throat with sore throat and dry cough. Then the virus progressively crawls along the bronchi. When the virus reaches the lungs, their mucous membranes become inflamed. This can damage the alveoli or lung bags that have to work harder to perform their function of supplying oxygen to the blood that circulates throughout our body and removing carbon dioxide from the blood.
Swelling and impaired flow of oxygen can cause those areas of the lungs to fill with fluid, pus and dead cells causing pneumonia. Precisely because of this degeneration, some patients experience serious respiratory problems, so much so that they must be hospitalized in intensive care and ventilated in the worst cases.
What Trajectory Does The Virus Take in the Lungs?
The lungs of a 28-year-old boy hospitalized in intensive care. The white clouded veil is an indication of pneumonia.
Dr. Shu-Yuan Xiao, professor of pathology at the University of Chicago School of Medicine and director of the Center for Pathology and Molecular Diagnostics at Wuhan University, interviewed by the New York Times, reviewed reports on the pathological course of coronavirus patients in China. He explained, but it is still a hypothesis, that the inflammation caused by the virus seems to start slowly in the peripheral areas on both sides of the lung and then spread (also taking some time) towards the upper respiratory tract, the trachea and other airways power plants, where no symptoms occur at a very early stage. This course could explain why in Wuhan, where the epidemic started, many of the first cases were not identified immediately.
The tests done at the beginning in many Chinese hospitals did not always detect an infection in the peripheral part of the lungs therefore, some people who showed symptoms, would have been sent home without treatment, and would then seek treatment in other hospitals or stay home, thereby infecting the rest of the family. “This is one of the reasons why there has been such a wide spread,” speculates the scientist.
What Happens to The Lungs?
Associate Professor of the University of Maryland School of Medicine Matthew B. Frieman, who studies highly pathogenic coronaviruses, interviewed by National Geographic, explained that in the first days of the infection the new coronavirus rapidly invades human lung cells which are of two types: those of the first type produce mucus, the others have hair-like structures, and are therefore called ciliates. When expelled, mucus helps protect lung tissues from pathogens and ensures that the organs responsible for breathing do not dry out. Hair cells have the task of “shaking” mucus, eliminating foreign bodies such as pollen or viruses. Frieman explains that SARS infected and killed the hair cells, which eventually detached, filling the patient’s airways with residues and fluids, and speculates that the same is happening in the case of the new coronavirus. And this would be the reason why many patients develop pneumonia from both lungs.
What is The Role of the Immune System?
In the second stage of the disease, the immune system comes into play. Alarmed by the presence of a viral invasion, our body is committed to fighting the disease by flooding the lungs with immune cells that have the task of eliminating damage and repairing lung tissue.
When working properly, this inflammatory process is strictly controlled and confined only to infected areas. But sometimes the immune system goes haywire and these cells kill everything they encounter, including healthy tissue. The abnormal response of our immune system can cause more harm than good, and doctors agree on this and, in the case of coronavirus, more and more residues clog the lungs and pneumonia gets worse and worse.
In the final stage, lung damage is so serious that death from respiratory failure can occur and, in some cases, lung damage would be permanent. Inflammation also makes the membranes between the air sacs and blood vessels more permeable, which causes fluid to enter the lungs, compromising their ability to oxygenate the blood.
In severe cases, the body practically fills the lungs with fluids and cannot breathe. Practically the organism fills the lungs with liquids and one cannot breathe.
What are Honeycomb Holes in The Lungs?
A recent study conducted by a team led by researchers from the Icahn School of Medicine Mount Sinai found that over half of 121 patients examined in China had normal chest X-rays at the beginning of their disease.
When the disease progresses, the CT scans show opacity, a sort of hazy veil in some areas of the lung typical of viral respiratory infections. Those dull areas can thicken when the disease gets worse, creating what radiologists call “honeycomb” hole formation. These holes are probably created by the overactive response of the immune system, which creates scars that protect and stiffen the lungs.
What Scientists Don’t Know About Coronavirus Patients Yet?
Not many things are known yet. Although the disease resembles SARS in many respects and has elements in common with flu and pneumonia, the course of the disease is not yet fully understood. Some patients may remain stable for over a week and then develop pneumonia suddenly. Other patients seem to recover, but then develop symptoms again.
Some patients in China have recovered but have fallen ill again. Relapses in some cases, the virus was still circulating and had not been detected by the swab. But in other cases the patients had damaged and vulnerable lung tissue, which was later attacked by bacteria. Some of these patients ended up dying from a bacterial infection, not the virus, although this is rare. Other cases are mysteries.
Dr. Xiao said he personally knew a man and his wife who had been infected but seemed to be improving. However, the man began to deteriorate and was hospitalized. He was in intensive care, he was receiving oxygen and he had written to his wife that he was improving, he had a good appetite and so on.
In the late afternoon, however, the woman stopped receiving messages. He didn’t know what was going on, and at 10 p.m., she received a notice from the hospital telling her that her husband had died.