What is COVID-19?

COVID-19 is the disease caused by an infection of the SARS-CoV-2 virus, first identified in the city of Wuhan, in China's Hubei province in December 2019. COVID-19 was previously known as 2019 Novel Coronavirus (2019-nCoV) respiratory disease before the World Health Organization (WHO) declared the official name as COVID-19 in February 2020.

The SARS-CoV-2 virus belongs to the family of viruses called coronaviruses, which also includes the viruses that cause the common cold, and the viruses that cause more serious infections such as severe acute respiratory syndrome (SARS), which was caused by SARS-CoV in 2002, and Middle East respiratory syndrome (MERS), which was caused by MERS-CoV in 2012. Like the other coronaviruses, the SARS-CoV-2 virus primarily causes respiratory tract infections, and the severity of the COVID-19 disease can range from mild to fatal. Serious illness from the infection is caused by the onset of pneumonia and acute respiratory distress syndrome (ARDS).

Symptoms

The most common symptoms of COVID-19 include dry cough, fever, and shortness of breath. It is thought that symptoms can appear between 2-14 days after exposure although there have been isolated cases which suggest this may be longer. If you develop symptoms, you should stay at home to prevent the spread of the disease into the community. Wearing a facemask will help prevent the spread of the disease to others.
Update: March 10, 2020 -- According to the latest research published in the Annals of Internal Medicine (March 10, 2020), the median incubation period is estimated to be 5 days, and almost all (~98%) patients who have been infected will develop symptoms within 12 days.

Transmission

The SARS-CoV-2 virus is thought to spread from person-to-person via:

droplet transmission (large respiratory droplets that people sneeze, cough or drip)
aerosol transmission (when someone coughs or sneezes in the room)
contact transmission (touching a contaminated surface then touching your mouth, nose or eyes)
direct transmission (kissing, shaking hands etc.)

Prevention

The best way to prevent infection is to avoid exposure to the virus.

The most important way to prevent COVID-19 is to WASH YOUR HANDS.

Wash your hands regularly and thoroughly with soap and water (lather for 20 seconds) OR use an alcohol based (at least 60%) hand sanitizer.

Other actions that help to prevent the spread of COVID-19:

avoid contact with others who are sick
avoid touching your mouth, nose, eyes or face
cover coughs and sneezes (into a tissue or into your elbow)
clean and disinfect surfaces (alcohol or bleach based cleaning solutions work best for coronaviruses)
facemasks will not protect you from COVID-19, but will help prevent the spread of the disease to others.
social distancing

What to do if you are sick?

Stay home except to get medical care

Stay home: Most people with COVID-19 have mild illness and are able to recover at home without medical care. Do not leave your home, except to get medical care. Do not visit public areas.
Stay in touch with your doctor. Call before you get medical care. Be sure to get care if you have trouble breathing, or have any other emergency warning signs, or if you think it is an emergency.
Avoid public transportation: Avoid using public transportation, ride-sharing, or taxis.

Call ahead before visiting your doctor

Call ahead: Many medical visits for routine care are being postponed or done by phone or telemedicine.
If you have a medical appointment that cannot be postponed, call your doctor’s office, and tell them you have or may have COVID-19. This will help the office protect themselves and other patients.