How COVID-19 Spreads

Person-to-person spread
The virus is thought to spread mainly from person-to-person.

Between people who are in close contact with one another (within about 6 feet).
Through respiratory droplets produced when an infected person coughs or sneezes.
These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

Can someone spread the virus without being sick?
People are thought to be most contagious when they are most symptomatic (the sickest).
Some spread might be possible before people show symptoms; there have been reports of this occurring with this new coronavirus, but this is not thought to be the main way the virus spreads.
Spread from contact with infected surfaces or objects
It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

How easily the virus spreads?
How easily a virus spreads from person-to-person can vary. Some viruses are highly contagious (spread easily), like measles, while other viruses do not spread as easily. Another factor is whether the spread is sustained, spreading continually without stopping.

The virus that causes COVID-19 seems to be spreading easily and sustainably in the community (“community spread”) in some affected geographic areas.

Community spread means people have been infected with the virus in an area, including some who are not sure how or where they became infected.

Situation in U.S.
Imported cases of COVID-19 in travelers have been detected in the U.S.
Person-to-person spread of COVID-19 was first reported among close contacts of returned travelers from Wuhan.
During the week of February 23, CDC reported community spread of the virus that causes COVID-19 in California (in two places), Oregon and Washington. Community spread in Washington resulted in the first death in the United States from COVID-19, as well as the first reported case of COVID-19 in a health care worker, and the first potential outbreak in a long-term care facility.
International Areas with Sustained (Ongoing) Transmission
Last updated February 28, 2020

China (Level 3 Travel Health Notice)
Iran (Level 3 Travel Health Notice)
Italy (Level 3 Travel Health Notice)
Japan (Level 2 Travel Health Notice)
South Korea (Level 3 Travel Health Notice)

Source: https://www.cdc.gov/