What Is Coronavirus?

rnCoronaviruses 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. WHAT YOU NEED TO KNOWrnCOVID-19rnCOVID-19 is the disease caused by SARS-CoV-2, the coronavirus that emerged in December 2019.rnCOVID-19 can be severe, and has caused millions of deaths around the world as well as lasting health problems in some who have survived the illness.rnThe coronavirus can be spread from person to person. It is diagnosed with a laboratory test.rnCOVID-19 vaccines have been authorized for emergency use by the U.S. Food and Drug Administration, and vaccination programs are in progress across the U.S. and in many parts of the world.rnPrevention involves physical distancing, mask-wearing, hand hygiene and staying away from others if you feel sick.rnHow 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?rnThe 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?rnSymptoms 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.