What exactly is coronavirus (COVID-19), where did it come from and how does it spread?
More than 800,000 people have been infected with the novel virus, with significant outbreaks in the US, Italy and Spain, and now more than 1,800 deaths in the UK.
What exactly is COVID-19?
Coronavirus disease 2019 (COVID-19) is caused by a coronavirus called SARS-CoV-2. A coronavirus is a type of virus that causes respiratory tract infections, such as colds and pneumonia. Although coronaviruses usually cause mild symptoms, they can (on rare occasions) cause life-threatening breathing difficulties and death.
Coronaviruses are a large group of viruses that are known to infect both humans and animals, and in humans cause respiratory illness that range from common colds to much more serious infections. The most well-known case of a coronavirus epidemic was Severe Acute Respiratory Syndrome (Sars), which, after first being detected in southern China in 2002, went on to affect 26 countries and resulted in more than 8,000 cases and 774 deaths.
Where did the disease originate?
Coronaviruses are common amongst animals. They’re ‘zoonotic’, meaning that they can be spread between humans and animals.
The reservoir - where microbes such as viruses live and grow - for the coronavirus (COVID-19) appears to be bats. Research into where the infection started is ongoing, but a major source of the outbreak has been traced to a large seafood and animal market in Wuhan city, China.
The majority of people initially infected by COVID-19 had contact with the market in Wuhan city. Due to the ability of the virus to spread from person to person, it has since been declared a pandemic.
Coronaviruses are a large family of viruses which may cause illness in animals or humans. In humans, several coronaviruses are known to cause respiratory infections ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). The most recently discovered coronavirus causes coronavirus disease COVID-19.
What are the symptoms of COVID-19?
The most common symptoms of COVID-19 are fever, tiredness, and dry cough. Some patients may have aches and pains, nasal congestion, runny nose, sore throat or diarrhoea. These symptoms are usually mild and begin gradually. Some people become infected but don’t develop any symptoms and don't feel unwell. Most people (about 80%) recover from the disease without needing special treatment. Around 1 out of every 6 people who gets COVID-19 becomes seriously ill and develops difficulty breathing. Older people, and those with underlying medical problems like high blood pressure, heart problems or diabetes, are more likely to develop serious illness.
People with fever, cough and difficulty breathing should seek medical attention.
How does the novel coronavirus (COVID-19) spread?
People can catch COVID-19 from others who have the virus. The disease can spread from person to person through small droplets from the nose or mouth which are spread when a person with COVID-19 coughs or exhales. These droplets land on objects and surfaces around the person. Other people then catch COVID-19 by touching these objects or surfaces, then touching their eyes, nose or mouth. People can also catch COVID-19 if they breathe in droplets from a person with COVID-19 who coughs out or exhales droplets. This is why it is important to stay more than 2 meters (3 feet) away from a person who is sick.
Can the virus that causes COVID-19 be transmitted through the air?
Studies to date suggest that the virus that causes COVID-19 is mainly transmitted through contact with respiratory droplets rather than through the air.
The virus that causes COVID-19 is mainly transmitted through droplets generated when an infected person coughs, sneezes, or speaks. These droplets are too heavy to hang in the air. They quickly fall on floors or surfaces.
You can be infected by breathing in the virus if you are within 2 metres of a person who has COVID-19, or by touching a contaminated surface and then touching your eyes, nose or mouth before washing your hands.
Updated 31st March 2020