Once the corona virus is able to penetrate into the bloodstream, not only the lungs, but almost any organ in the body, can become the target of this dangerous pathogen.
For most patients with new coronary virus infection, the disease will appear as well as end in the lungs, because like flu, COVID-19 is a respiratory disease.
Looking back at the SARS (Severe Acute Respiratory Syndrome) pandemic, caused by SARS-CoV virus, a close relative of the new corona virus, through research and reports, the World Health Organization (WHO) concludes. that, the disease attacks the lungs in three stages: viral replication, overreaction of the immune system and lung destruction.
Not all patients go through all three stages. In fact, only about 25% of SARS patients experience complications of respiratory failure (classified as a severe case). According to the data collected so far, COVID-19 also showed similar statistics, with 82% of cases having mild symptoms and the remainder falling into severe or critical cases.
According to Professor Matthew B. Frieman, University of Maryland, an in-depth researcher of viral pathology, in the first days after infection, the new corona virus will quickly attack lung cells. These lung cells will be divided into two types: mucus cells and hair cells.
Talking about these two types, mucus will cover the outer layer of the organs in the respiratory system, tasking to protect lung tissue from pathogens and prevent drying out. Meanwhile, the hair cells will sweep continuously to remove dirt such as pollen or virus, kept in mucus, outside the body, with the help of coughing action.
Prof. Frieman explained that SARS will focus on infecting and destroying the hair cells, leading to the condition that the patient’s airway is filled with dirt and fluids. The expert also hypothesized that a similar “tactics” attack in the new corona virus. This hypothesis is now being supported by the earliest studies of COVID-19, showing that many patients develop pneumonia in both lungs, along with symptoms such as shortness of breath.
The pathogen attack is also the trigger for the second stage of lung destruction. At this point, the immune system will respond to foreign invaders, by launching an army of immune cells that flood the lungs, to clean the infected cells, as well as repair them. Damaged lung tissue.
If functioning smoothly, the inflammatory response (immune response) will be tightly regulated to appear only confined to areas affected by the virus. However, in some cases, your immune system will respond uncontrollably and these cells will destroy anything in its path, including healthy tissue.
“Therefore, you will be hurt more than you are mitigating the previous damage, by the immune response itself. The situation has also worsened pneumonia, ”said Professor Frieman.
Moving on to stage 3, the lesions on the lungs are constantly increased and to some degree will lead to respiratory failure, meaning the patient cannot perform oxygen exchange function on their own, but requires ventilator help. Even if the patient is healed, they can still live with two permanently damaged lungs. According to WHO, SARS creates small holes in the lungs, making them look like beehives, and this pattern of lung damage has also been observed in Covid -19 patients.
These holes in the lungs are mainly created by the overactive response of the immune system, by creating scar tissue that both plays a protective role and hardens the lungs. However, if there is too much scar tissue, the lungs will gradually lose their ability to breathe. In addition, the inflammatory reaction also makes the membranes between the alveoli and blood vessels more permeable, which causes the lungs to flood and affect the ability of oxygen to supply blood.
“In critical cases, the lungs will basically be flooded with fluid and the patient cannot breathe. This is also the way they die ”- Professor Frieman emphasized.
During the SARS and MERS pandemic (Middle East Respiratory Syndrome), nearly a quarter of patients had diarrhea, which is a characteristic symptom of corona-related illnesses. According to statistics so far, diarrhea and abdominal pain are quite rare in COVID-19 cases.
If you are wondering why respiratory viruses can cause intestinal diseases, know that, when this pathogen attacks the body, it will search and penetrate cells through a key mechanism. – lock. Specifically, the virus spikes will be compatible with one / several types of receptors on the host cell surface, and only when compatible can it penetrate.
Some viruses are quite picky about the compatible host cell type, while others are “easier” and can invade many different types of cells. Taking the prime example of the SARS and MERS virus, these pathogens are compatible with both cells on the intestinal wall, thereby causing damage to these organs or leading to diarrhea. Whether or not the new corona virus has such properties is currently unclear. Many researchers believe that the virus is also compatible with the same receptor as SARS, which occurs in both lung and small intestine cells.
There are also several studies showing the presence of new coronavirus in the stool sample of patients. However, in order to reach the conclusion that the new corona virus can spread through this waste, other scientific evidence is still required.
Excessive immune response to corona virus also causes problems outside of the lungs. “Instead of shooting with a gun, your body uses a whole rocket. It was really a cytokine storm, ”says Angela Rasmussen, a virologist at Columbia University (cytokine is a protein that signals and directs immune cells to the site of infection).
Excessive immune response means a cytokine storm will lead to a reaction that weakens blood vessels in the lungs, allowing body fluids to enter the alveoli. “Basically you will bleed in” – Angela Rasmussen analyzed.
The cytokine storm will also sweep through the circulatory system and create problems on many other organs. In 2014, patients with MERS also reported symptoms of thrombocytopenia and leukemia, hypotension, cardiac arrest. In some severe cases of COVID-19, the cytokine response combined with a reduced ability to pump oxygen throughout the body has also led to multiple organ failure.
In the SARS and MERS outbreak and most recently COVID-19, doctors observed liver damage. The severity of the damage is usually mild, but with severe cases the liver damage also increases, even in cases of liver failure. So how does this happen?
Once the virus has entered the bloodstream, it can swim to any organ. In particular, the liver, which is an organ of many blood vessels, will be where the virus easily penetrates. However, the characteristic of being an organ is able to recover and regenerate new cells very quickly, the damage caused by viruses on the liver is usually mild. Until now, scientists still do not understand how the corona virus attacks the liver. Some suggested that the virus will penetrate into the liver, multiply and destroy cells. Other ideas are likely to be due to the damage caused by excessive immune response on the liver.
The kidney also cannot escape becoming a victim of the new corona virus. In the past, a significant number of MERS patients also faced acute kidney damage. Studies also show that the new corona virus can cause the same problem. Although kidney damage is not specific to the disease caused by this strain, this is one of the causes of death. According to statistics, 91.7% of SARS patients with acute renal failure died.
The renal ureters (small tubules in the kidney) are the most vulnerable to corona virus. After the SARS pandemic, WHO announced that the virus was found in the ureters and caused inflammation. “It is not uncommon to detect viruses in the ureter, once they have entered the bloodstream,” said Professor Kar Neng Lai, University of Hong Kong. According to the expert, because the kidneys are constantly filtering the blood, in some cases, the ureter will retain the virus (already in the blood), thereby causing both short-term and mild damage.
These lesions can only be fatal once the virus enters the cell and begins to multiply. However, according to experts there is currently no evidence that the SARS virus can replicate in the kidney. Patients with acute kidney damage may be due to a combination of a range of other problems such as: low blood pressure, sepsis, medication side effects or metabolic disorders. For more severe cases of kidney failure, one of the causes that is discovered is not so strange: cyclone cytokine.
|Country / Territory||Number of infections||Dead||Suspected of infection||Recover|
|United Arab Emirates||9||0||0||1|
Statistical data sheet dated 02/18/2020 by Vietnam Ministry of Health
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