Coronaviruses are a type of virus. There are many different kinds, and some cause disease. A coronavirus identified in 2019, SARS-CoV-2, has caused a pandemic of respiratory illness, called COVID-19.
COVID-19 affects different people in different ways. Infected people have had a wide range of symptoms reported – from mild symptoms to severe illness.
Symptoms may appear 2-14 days after exposure to the virus. People with these symptoms may have COVID-19:Fever or chillsCoughShortness of breath or difficulty breathingFatigueMuscle or body achesHeadacheNew loss of taste or smellSore throatCongestion or runny noseNausea or vomitingDiarrheaLook for emergency warning signs for COVID-19. If someone is showing any of these signs, seek emergency medical care immediately:Trouble breathingPersistent pain or pressure in the chestNew confusionInability to wake or stay awakePale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone
Most common symptoms:feverdry coughtirednessLess common symptoms:aches and painssore throatdiarrhoeaconjunctivitisheadacheloss of taste or smella rash on skin, or discolouration of fingers or toes
How does the coronavirus spread?
As of now, researchers know that the coronavirus is spread through droplets and virus particles released into the air when an infected person breathes, talks, laughs, sings, coughs or sneezes. Larger droplets may fall to the ground in a few seconds, but tiny infectious particles can linger in the air and accumulate in indoor places, especially where many people are gathered and there is poor ventilation. This is why mask-wearing, hand hygiene and physical distancing are essential to preventing COVID-19
How did the coronavirus start?
The first case of COVID-19 was reported Dec. 1, 2019, and the cause was a then-new coronavirus later named SARS-CoV-2. SARS-CoV-2 may have originated in an animal and changed (mutated) so it could cause illness in humans. In the past, several infectious disease outbreaks have been traced to viruses originating in birds, pigs, bats and other animals that mutated to become dangerous to humans. Research continues, and more study may reveal how and why the coronavirus evolved to cause pandemic disease.
What is the incubation period for COVID-19?
Symptoms show up in people within two to 14 days of exposure to the virus. A person infected with the coronavirus is contagious to others for up to two days before symptoms appear, and they remain contagious to others for 10 to 20 days, depending upon their immune system and the severity of their illness.
How is COVID-19 diagnosed?
COVID-19 is diagnosed through a laboratory test. Diagnosis by examination alone is difficult since many COVID-19 signs and symptoms can be caused by other illnesses. Some people with the coronavirus do not have symptoms at all. Learn more about COVID-19 testing.
How is COVID-19 treated?
Treatment for COVID-19 addresses the signs and symptoms of the infection and supports people with more severe disease. For mild cases of coronavirus disease, your doctor may recommend measures such as fever reducers or over-the-counter medications. More severe cases may require hospital care, where a patient may receive a combination of treatments that could include steroids, oxygen, mechanical breathing support and other COVID-19 treatments in development. Infusions of monoclonal antibodies given to certain patients early in the infection may reduce the symptoms, severity and duration of the illness.
How do you protect yourself from this coronavirus?
Vaccines are now authorized to prevent infection with SARS-CoV-2, the coronavirus that causes COVID-19. But until more is understood about how the vaccines affect a person’s ability to transmit the virus, precautions such as mask-wearing, physical distancing and hand hygiene should continue regardless of a person’s vaccination status to help prevent the spread of COVID-19. Learn more about the COVID-19 vaccine and ways to protect yourself.
Does COVID-19 cause death?
Yes, severe COVID-19 can be fatal. For updates of coronavirus infections, deaths and vaccinations worldwide, see the Coronavirus COVID-19 Global Cases map developed by the Johns Hopkins Center for Systems Science and Engineering.
Why is it called coronavirus?
Coronaviruses are named for their appearance: “corona” means “crown.” The virus’s outer layers are covered with spike proteins that surround them like a crown.
Is this coronavirus different from SARS?
SARS stands for severe acute respiratory syndrome. In 2003, an outbreak of SARS affected people in several countries before ending in 2004. The coronavirus that causes COVID-19 is similar to the one that caused the 2003 SARS outbreak.
Since the 2019 coronavirus is related to the original coronavirus that caused SARS and can also cause severe acute respiratory syndrome, there is “SARS” in its name: SARS-CoV-2. Much is still unknown about these viruses, but SARS-CoV-2 spreads faster and farther than the 2003 SARS-CoV-1 virus. This is likely because of how easily it is transmitted person to person, even from asymptomatic carriers of the virus.
Are there different variants of this coronavirus?
Yes, there are different variants of this coronavirus. Like other viruses, the coronavirus that causes COVID-19 can change (mutate). In December 2020, B.1.1.7, a new variant, was identified in the United Kingdom, and since then, variants have appeared in other locations around the world, including B.1.351, first isolated in South Africa, and others. Mutations may enable the coronavirus to spread faster from person to person, and may cause more severe disease. More infections can result in more people getting very sick and also create more opportunity for the virus to develop further mutations. Read more about coronavirus variants.