COVID-19 is a disease caused by the coronavirus called SARS-CoV-2. This video will show how the virus is transmitted, what are the symptoms of COVID-19, how the virus enters the body, and how our body responds to it. We will also look at what happens in the case of severe COVID-19 and why it is so dangerous. Lastly, you will learn more about what you can do to prevent this disease.
Hi, my name is Dr. Marta Gabryelska and today I will present basic verified facts about COVID-19 infections. And this presentation was created with BioRender. COVID-19 is the disease caused by a new Coronavirus, called SARS-Cov-2. The world first learnt of this new virus on 31st of December 2019, following a report of a cluster of cases of viral pneumonia in Wuhan, China. The virus is composed of several elements. The most important of them is RNA genome containing information how to overtake the human cells and build more viruses. The other important part is a spike protein, which serves as a key to open human cells through ACE2 receptor. As you can see, Spike protein and ACE2 receptor perfectly fit with one another. This interaction is starting the infection, allowing virus to enter the cell and create more copies of itself. As the number of viruses increase in the body, symptoms can be observed. The most common symptoms of COVID-19 are dry cough, difficulty breathing fatigue with high fever. Other symptoms that are less common, and may affect some patients, include loss of taste, or smell, nasal congestion, sore throat, headache, muscle or joint pain, different types of skin rash, nausea, or vomiting, diarrhea, chills, or dizziness. The time from exposure to COVID-19 to the moment when the symptoms begin is on average five to six days and can range from 1 to 14 days. This is why people who have been exposed to the virus are advised to remain at home and stay away from others for 14 days in order to prevent the spread of the virus, especially where testing is not easily available. After infection started, the number of viral copies is increasing until the antibodies are made and can fight the infection. Because early on the body doesn’t have antibodies, PCR test is used to detect COVID-19 infection. As you can see, there are two types of antibodies. IgM and IgG. IgM antibodies detect and fight the current infection. IgG antibodies contain information about the infection and can protect from COVID-19 coming back. However, as you can see, the numbers are dropping post the infection, they do not guarantee that you will not be infected again. In most situations, a PCR test is used to detect SARS-Cov-2 and confirm the infection. Polymerase chain reaction, or PCR, is the most commonly used molecular test. Samples are collected from the nose and/or throat with a swab. This tests detect the virus in the sample by extracting its viral RNA, changing it into DNA and amplifying it. For this reason, a molecular test is used to confirm an active infection, usually within a few days of exposure and around the time that the symptoms may begin. The diagnosis time is relatively long and difficult, and it’s suitable from early to advance infection. Anyone with symptoms should be tested wherever possible. People who do not have symptoms but have had close contact with someone who is or may be infected may also consider testing. While a person is waiting for the results, they should remain isolated from others. Antibody tests can tell us whether someone has had an infection in the past even if they have not have symptoms. Also known as serological tests, and usually done on a blood sample. These tests can detect antibodies produced in response to the infection. In most people antibodies start to develop after days to weeks and can indicate if the person had had the past infection. These tests are relatively fast and easy, but are used to detect advanced infection or it can be used in a recovered patients. To understand why COVID-19 is a threat, let’s have a look what is happening in the human body after contracting the virus. After entering the body, through the mouth or nose, SARS-Cov-2 makes it way into the lungs, which are built from these little circular sacs, allowing so called gas exchange, meaning getting rid of CO2 and taking oxygen into our bodies. In response to the presence of the virus, the immune system attacks the area of infection, killing healthy cells in the process. In result, there is a reduced amount of so called surfactant that is important and allows lungs to easily expand during breathing. Additionally, weakend blood vessels allow fluid to seep and fill lung cavities leading to a respiratory failure. In severe cases, fluid accumulating in the lungs is causing reduced or severely hindered exchange of CO2 into oxygen, the main system that keeps us alive. It can be compared to drowning in your own fluids. Let’s compare how the healthy lungs look like in comparison to lungs injured by COVID-19 infection. The weakened veins are leaking more fluid, alarmed immune cells are sending more signals for calling for help. And this is causing an immunological storm in the body. The veins are further apart from the lungs, which is jeopardizing CO2 and oxygen exchange even more. The lungs are severely inflamed. Symptoms of severe COVID-19 disease include shortness of breath, loss of appetite, confusion, persistent pain or pressure in the chest and high temperature above 38 degrees. Among those who develop symptoms, most, about 80%, recover from the disease without needing hospital treatment. However, about 15% become seriously ill and require oxygen and 5% become critically ill and need intensive care. Complications leading to death may include respiratory failure, acute respiratory distress syndrome, sepsis, and septic shock, developing blood clots and/or multi organ failure, including injury of the heart, liver, or kidneys. People aged 60 years and over and those with underlying medical problems like high blood pressure, heart and lung problems, diabetes, obesity, or cancer are at higher risk of developing serious illness. However, anyone can get sick with COVID-19 and become seriously ill or die at any age. COVID-19 is airborne which means it is transmitted from liquid particles in the air. Prolonged contact with infected person or touching surfaces exposed to the virus increase the risk of infection. Stay safe by taking some simple precautions such as regularly cleaning your hands, desinfecting high touch surfaces, wearing masks if you are sick or advised to, avoid non essential international travel, self isolate and practice social distancing, caughing to your elbow, tissues and dispose of them and get vaccinated if you have the opportunity. If you are worried about vaccinations, check out our other videos where we talk about vaccine safety. If you contracted COVID-19 stay hydrated. Contact your doctor and monitor your symptoms and rest, your body is weakend and is fighting the infection. In case of emergency, seek medical attention immediately. Also, check local advice where you live and work. Thank you for watching with STEMcognito. Find more videos using the search box or the drop down menus above. If you think there’s something wrong with this video, please use the Report button to inform the STEMcognito team. Questions about the video content should be directed to the researcher. You can find their details below. Go to our submission pages to find out how to submit your own video. Don’t forget to follow us on social media.
