How COVID-19 (Coronavirus) Spreads
COVID-19 is a new disease and we are still learning how it spreads, the severity of illness it causes, and to what extent it may spread in the United States.
How COVID-19 Spreads
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 contaminated 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.
Different parts of the country are seeing different levels of COVID-19 activity. The United States nationally is currently in the initiation phases, but states where community spread is occurring are in the acceleration phase. The duration and severity of each phase can vary depending on the characteristics of the virus and the public health response.
- CDC and state and local public health laboratories are testing for the virus that causes COVID-19.
- More and more states are reporting cases of COVID-19 to CDC.
- U.S. COVID-19 cases include:
- Imported cases in travelers
- Cases among close contacts of a known case
- Community-acquired cases where the source of the infection is unknown.
- Three U.S. states are experiencing sustained community spread.
- View latest case counts, deaths, and a map of states with reported cases.
Last updated March 12, 2020
- China (Level 3 Travel Health Notice)
- Iran (Level 3 Travel Health Notice)
- Most of Europe (Level 3 Travel Health Notice)
- South Korea (Level 3 Travel Health Notice)
- Global Outbreak Notice (Level 2 Travel Health Notice)
For additional information, please visit CDC’s Travel Information page.
Page last reviewed: March 4, 2020