Health experts share that SARS-CoV-2 has the ability to invade and damage internal organs.
Until now, although scientific research and clinical reports on Covid-19 disease have been published in specialized journals, human knowledge about this disease is still very limited, both about Pathogenesis, treatment direction as well as preventive vaccine.
SARS-CoV-2 virus is very small but unpredictable harm in many cases. So how dangerous is it after SARS-CoV-2 virus enters the body?
Most people infected with the SARS-CoV-2 virus are thought to be from the respiratory tract. SARS-CoV-2 virus enters the nose and throat because the cells here have many receptors on the surface of the cell called ACE2 (angiotensin-converting enzyme 2, angiotensin 2 conversion enzyme).
The SARS-CoV-2 virus uses its surface protein to bind to these ACE2 receptors in such a way that the key looks into a lock to open a door into the home, invading the host cell. Once inside, the virus takes over the cell, using existing materials inside the cell to make countless copies of itself and invade new cells.
In the first week after infection, the virus often replicates a lot and patients can secrete countless copies of it from respiratory fluids, such as water droplets from coughing, sneezing or even breathing and talking normally (this is the reason we have to use masks this season to protect others and ourselves).
Possible symptoms at this time are fever, dry cough, sore throat, loss of smell and taste, or headache and muscle aches. However, there are many cases where patients also show no symptoms!
In the first week after infection, the virus often replicates a lot and patients can secrete countless copies of it from respiratory fluids, such as water droplets from coughing, sneezing or even breathing, talking normally.
If the immune system fails to defeat nCoV in this early stage, the virus will move down the trachea, where the thinner, deeper branches of the respiratory system are the lungs, ending with small air sacs called are alveoli, each branch is lined with a cell layer is also rich in ACE2 receptors. During this period the virus can cause more serious damage, even possibly leading to death.
With the normal function of the lungs, oxygen passes through the alveoli into the capillaries, then oxygen is delivered to the rest of the body. But when the immune system was fighting the nCoV virus, it was this battle that damaged the oxygen transport system.
The frontline white blood cells that recognize the presence of the invader release molecules called chemokines, which summon more immune cells to help kill the infected cells.
The battle of immune cells secretes a lot of inflammatory cytokine molecules (also known as cytokine storms), leaving behind a plethora of fluids and dead cells, something we often refer to as " pus".
The accumulation of pus in the lungs causes the underlying pathology of pneumonia, with the corresponding symptoms such as cough, fever, shortness of breath, and shallow breathing. Therefore, the delivery of oxygen in such adverse events is very important and shows that many patients recover from their illnesses only through assisted breathing (not medication).
How the virus attacks the heart and blood vessels is still a poorly understood thing, but more and more evidence from recent scientific reports suggests this is a fairly common phenomenon. An article published in March in "JAMA Cardiology" reported heart damage in nearly 20% of the 416 hospitalized patients for SARS-CoV-2 virus in Wuhan, China.
In another study in Wuhan, 44% of the 36 hospitalized patients who had to be treated in a special intensive care unit (ICU) had arrhythmia. Symptoms affecting the heart caused by SARS-CoV-2 virus seem to be caused by blood.
According to a scientific paper published in April in the journal "Thrombosis Research", of 184 patients with SARS-CoV-2 virus who had to be treated in a special intensive care unit in the Netherlands, 38% had blood clots. often and nearly a third already have a blood clot.
The blood clots can burst and enter the lungs, blocking important arteries that cause pulmonary embolism. Blood clots from arteries can also clog blood vessels in the brain, causing a stroke.
Scientists are working to understand exactly what causes cardiovascular damage caused by the SARS-CoV-2 virus. Is it possible for viruses to strike directly on the mucosa of the heart and blood vessels, the same way they attack the nose and alveoli (which is very rich in the ACE2 receptor)? or perhaps due to lack of oxygen, chaos in the lungs, indirectly affecting vascular lesions?
Understanding these things may help explain why patients with vascular disease, such as diabetes and high blood pressure, are at risk of developing SARS-CoV-2. more serious.
Recent data from the Centers for Disease Control and Prevention (CDC) on patients admitted to hospitals in 14 states shows that about one-third has chronic lung disease but nearly the same number as people with the disease. diabetes and half are high blood pressure.
During the SARS-CoV-2 pandemic, in addition to ventilator support, dialysis is also important because the kidney is also the place where cells express abundant ACE2 receptors, becoming another viral target. . In a study using electron microscopy, virus presence was found in kidney cells from patients who died of SARS-CoV-2 disease.
According to a scientific report, 27% of the 85 patients admitted to Wuhan have kidney failure. Another report said 59% of nearly 200 SARS-CoV-2 patients hospitalized in China, Hubei and Sichuan provinces had protein and 44% had blood in their urine, both of which were signs of damage. kidney injury. Patients with SARS-CoV-2 with acute kidney damage will have a 5-times higher probability of dying than other patients.
The big picture of the devastation that SARS-CoV-2 caused on the human body today is still a sketch with many blurry points. It will take years of hard research to understand it, which can draw a sharper and more realistic picture.
ACE2 receptors are present in the cortex and brain stem (cortex and brain stem) but it is still not clear in what cases the virus enters the brain and interacts with these receptors. During the 2003 SARS virus pandemic, SARS-CoV-2 virus was found to be able to penetrate nerve cells and sometimes cause encephalitis.
In April, a study published in the International Journal of Infectious Diseases, from a research team in Japan, showed traces of SARS-CoV-2 in the cerebrospinal fluid of a SARS patient. -CoV-2 causes meningitis and encephalitis, also showing that it can penetrate the central nervous system.
However, other factors can also cause brain damage such as a "cytokine storm" that can cause brain swelling, and the aforementioned blood clot can cause a stroke.
A scientific article in "The American Journal of Gastroenterology" reports a case in early March, a 71-year-old woman from Michigan returned from a cruise on the Nile with diarrhea. bleeding, vomiting and abdominal pain. Doctors initially suspected she had a common intestinal disease, such as Salmonella.
But after seeing her cough, doctors took a nasal swab and showed positive for SARS-CoV-2. The stool sample is also positive for viral RNA, signs of colon damage are also seen through endoscopy. This case was diagnosed with coronavirus gastrointestinal infection.
So far, viral RNA has been found in approximately 53% of fecal samples of SARS-CoV-2 patients. The presence of the virus in the gastrointestinal tract raises concerns that it may pass through the stool.
But it is currently not clear whether feces containing intact viruses are capable of transmitting or only viral RNA and proteins and there is no evidence to suggest that viral faecal transmission is important.
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