Coronavirus Disease 2019 (COVID-19)

The Centers for Disease Control and Prevention (CDC) is responding to an outbreak of respiratory disease caused by a novel (new) coronavirus that was first detected in China and which has now been detected in more than 100 locations internationally, including in the United States. The virus has been named SARS-CoV-2 (formerly commonly referred to as 2019-nCoV), and the disease it causes has been named coronavirus disease 2019 (abbreviated COVID-19).

There is an ongoing investigation to determine more about this outbreak. This is a rapidly evolving situation, and information will be updated as it becomes available. You can read the full situational summary at Link opens in a new window

How COVID-19 Spreads

COVID-19 is a new disease, and researchers are still learning how it spreads, the severity of illness it causes, and to what extent it may spread in the United States.

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 six 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.

In addition to CDC, many public health laboratories are now testing for the virus that causes COVID-19. With this increase in testing, more states have reported cases of COVID-19 to CDC. View the latest case counts, deaths, and a map of states with reported cases at Link opens in a new window

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

International Areas with Sustained (Ongoing) Transmission

(This was last updated February 28, 2020.)

  • China
  • Iran
  • Italy
  • Japan
  • South Korea

All COVID-19 travel-health notices can be found here: Link opens in a new window

The CDC updates a world map of confirmed COVID-19 cases at Link opens in a new window

Watch for symptoms.

Reported illnesses have ranged from mild symptoms to severe illness and death for confirmed coronavirus disease 2019 (COVID-19) cases. The following symptoms may appear two to 14 days after exposure*:

  • Fever
  • Cough
  • Shortness of breath

(*This is based on what has been seen previously as the incubation period of MERS-CoV viruses.)

Call your doctor in either of these circumstances.

Call your doctor if you


There is currently no vaccine to prevent coronavirus disease 2019 (COVID-19). The best way to prevent illness is to avoid being exposed to this virus. The virus is thought to spread mainly from person to person.

Older adults and people who have severe underlying chronic medical conditions like heart or lung disease or diabetes seem to be at higher risk for developing more serious complications from COVID-19 illness. Please consult with your health care provider about additional steps you may be able to take to protect yourself.

Take steps to protect yourself.

Clean your hands often.

  • Wash your hands often with soap and water for at least 20 seconds, especially after you have been in a public place, or after blowing your nose, coughing, or sneezing.
  • If soap and water are not readily available, use a hand sanitizer that contains at least 60 percent alcohol. Cover all surfaces of your hands, and rub them together until they feel dry.
  • Avoid touching your eyes, nose, and mouth with unwashed hands.

Avoid close contact.

Take steps to protect others.

Stay home if you're sick.

Stay home if you are sick, except to get medical care. Link opens in a new windowLearn what to do if you are sick.

Cover coughs and sneezes.

  • Cover your mouth and nose with a tissue when you cough or sneeze, or use the inside of your elbow.
  • Throw used tissues in the trash.
  • Immediately wash your hands with soap and water for at least 20 seconds. If soap and water are not readily available, clean your hands with a hand sanitizer that contains at least 60 percent alcohol.

Wear a facemask if you are sick.

  • If you are sick: You should wear a facemask when you are around other people (e.g. sharing a room or vehicle) and before you enter a health care provider's office. If you are not able to wear a facemask (e.g. because it causes trouble breathing), then you should do your best to cover your coughs and sneezes, and people who are caring for you should wear a facemask if they enter your room.
  • If you are NOT sick: You do not need to wear a facemask unless you are caring for someone who is sick (and they are not able to wear a facemask). Facemasks may be in short supply and they should be saved for caregivers.

Clean and disinfect.

  • Clean and disinfect frequently touched surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.
  • If surfaces are dirty, clean them: Use detergent or soap and water prior to disinfection.
  • To disinfect, most common household disinfectants will work. Other options include diluting your household bleach or solutions with at least 70 percent alcohol.
Save the bumblebees

U.S. Centers for Disease Control and Prevention (CDC), National Center for Immunization and Respiratory Diseases (NCIRD), Division of Viral Diseases. (Revised 2020, March 4–10 & February 29). COVID-19 situation summary: Background [Excerpt] & How it spreads, Symptoms, Prevention & treatment. In About COVID-19: What you should know. Retrieved March 10, 2020, from