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The Facts About COVID-19

Learn more about SARS-CoV2, the coronavirus that causes COVID-19.
The SARS-CoV-2 virus
© University of Glasgow

At the end of 2019 a new coronavirus infection was identified in Wuhan, China. The new virus is thought to have made the jump from animal species to humans and is called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). It causes the disease COVID-19. The virus is highly transmissible, infections spread quickly and can cause serious disease and death. The World Health Organization declared the outbreak a Public Health Emergency of International Concern on 30 January 2020, and a pandemic on 11 March 2020. On March 23rd 2020 the UK entered its first period of lockdown.

The Coronavirus Family

SARS-CoV2 is related to other coronaviruses, SARS, MERS and four coronaviruses that cause the common cold. SARS and SARS-CoV-2 enter cells in the respiratory tract by binding to a receptor called the Angiotensin-Converting Enzyme 2 (ACE2) receptor using spike proteins on their surface. Once inside the body’s cells the virus starts replicating. It is the spike protein on the SARS-CoV-2 virus that is the target of most effective vaccines.

This is an additional video, hosted on YouTube.


Symptoms linked to COVID-19 include a high fever, fatigue, a persistent dry cough and loss of taste and smell. More worrying symptoms include severe breathlessness.

Disease Course

In about 80% of people, the disease is mild and resolves over a period of about 10 days with supportive treatment such as bed rest, plenty of fluids, and over-the-counter medication such as paracetamol. However, in a smaller percentage of people, particularly those with additional medical issues, the disease is much more severe resulting in severe respiratory problems which can require admission to the hospital or the Intensive Care Unit. In some patients, a strong immune response to the virus results in a cytokine storm which can result in severe respiratory distress and respiratory failure. This is generally the cause of death in those who die from COVID-19 along with multi-organ failure. Sadly over 4 million people worldwide have lost their lives to COVID-19, over 130,000 of those within the UK.


Some people have symptoms related to COVID-19 long after the infection has gone. Because so many people have symptoms of long COVID, efforts are being directed towards research and specialist clinics to find effective treatments. Symptoms of long COVID may last for months and include extreme tiredness (fatigue), shortness of breath, chest pain or tightness, problems with memory and concentration (“brain fog”), difficulty sleeping (insomnia), heart palpitations, dizziness, pins, and needles, joint pain, depression and anxiety, tinnitus, earaches, feeling sick, diarrhoea, stomach aches, loss of appetite, a high temperature, cough, headaches, sore throat, changes to sense of smell or taste and rashes.

Transmission of COVID-19

The latest information from the World Health Organisation on the transmission of COVID-19 states:

“We know that the disease is caused by the SARS-CoV-2 virus, which spreads between people in several different ways.
The virus can spread from an infected person’s mouth or nose in small liquid particles when they cough, sneeze, speak, sing or breathe. These particles range from larger respiratory droplets to smaller aerosols.
Current evidence suggests that the virus spreads mainly between people who are in close contact with each other, typically within 1 metre (short-range). A person can be infected when aerosols or droplets containing the virus are inhaled or come directly into contact with the eyes, nose, or mouth. The virus can also spread in poorly ventilated and/or crowded indoor settings, where people tend to spend longer periods of time. This is because aerosols remain suspended in the air or travel farther than 1 metre (long-range). People may also become infected by touching surfaces that have been contaminated by the virus when touching their eyes, nose or mouth without cleaning their hands.”

It is the aerosol spread of the virus combined with issues around ventilation that have had the most impact on dentistry.

Virus Variants

Like all viruses, SARS-CoV-2 mutates and while most of these variants are of no consequence there are four that are currently variants of concern, these are Alpha, Beta Gamma, and Delta. This short video will tell you a bit more about virus variants.

This is an additional video, hosted on YouTube.

© University of Glasgow
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