Microscopic Rendering of Coronavirus
Coronavirus disease 2019 (COVID-19) is a virus (more specifically, a coronavirus) identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China.


What is coronavirus?

Coronaviruses are a family of viruses that can cause respiratory illness in humans. They get their name, “corona,” from the many crown-like spikes on the surface of the virus. Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and the common cold are examples of coronaviruses that cause illness in humans.

The new strain of coronavirus, COVID-19, was first reported in Wuhan, China in December 2019. The virus has since spread to all continents (except Antarctica).

How many people are infected with COVID-19?

The number of people infected changes daily. Organizations that collect this information, including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), are gathering information and continuously learning more about this outbreak. As of this writing (4/2/2020), more than 1,000,000 people in the world (of which more than 82,000 are in China and surrounding western pacific countries) have been infected. More than 50,000 people have died. Some 181 countries and territories on all continents (except Antartica) have now reported cases of COVID-19. The U.S. has the highest number of cases, with over 235,000 people infected. Italy has reported over 115,000 cases, Spain has more than 110,000 cases and Germany has reported close to 85,000 cases. For the latest statistics, see the World Health Organization's situation reports and references at end of article.

How does the new coronavirus (COVID-19) spread from person to person?

COVID-19 is likely spread the same way other human coronaviruses, like the cold, are spread:

  • When the virus becomes airborne and travels in respiratory droplets when an infected person coughs, sneezes or talks near you (within six feet). This is thought to be the main way COVID-19 is spread.
  • From close contact (touching, shaking hands) with an infected person.
  • By touching surfaces that the virus has landed on, then touching your eyes, mouth, or nose before washing your hands.

COVID-19 enters your body through your mouth, nose or eyes (directly from the airborne droplets or from transfer of the virus from your hands to your face). The virus travels to the back of your nasal passages and mucous membrane in the back of your throat. It attaches to cells there, begins to multiply and moves into lung tissue. From there, the virus can spread to other body tissues.

It's important to know that scientists are seeing cases of COVID-19 in people who were infected by individuals who had COVID-19 but were not yet showing symptoms. This is why many governments are requiring a 14-day isolation period for people returning from areas of outbreak. Governments, health agencies, researchers and healthcare providers are all working together to develop policies and procedures to limit the spread of this virus both globally and from individual to individual.

Who is most at risk for getting COVID-19?

Persons at greatest risk of contracting COVID-19 are:

  • People who live in or have recently traveled to any area with ongoing active spread.
  • People who have had close contact with a person who has a laboratory-confirmed or a suspected case of the COVID-19 virus.
  • People over age 60 who have pre-existing medical conditions or a weakened immune system.

If I recover from a case of COVID-19, can I be infected again?

The U.S. Centers for Disease Control says that "the immune response to COVID-19 is not yet understood." Because this is a new strain of coronavirus, scientists are still collecting information and research on the virus so it's still too early to know.

Symptoms and Causes

What are the symptoms of the novel coronavirus (COVID-19) infection?

Patients with confirmed infection from the COVID-19 virus reported these respiratory symptoms:

  • Fever (not always present).
  • Difficulty breathing/Shortness of breath.
  • Cough.

Other possible coronavirus symptoms of COVID-19 include:

  • Sore throat.
  • Body aches.
  • Diarrhea.
  • Tiredness.

Symptoms can range in severity from very mild to severe. In about 80% of patients, COVID-19 causes only mild symptoms.

How soon do symptoms of COVID-19 appear?

Symptoms of COVID-19 appear within two to 14 days after being exposed to the virus.

Diagnosis and Tests

How is COVID-19 diagnosed?

COVID-19 is diagnosed with a laboratory test. Your healthcare provider may collect a sample of your saliva or swab your nose or throat to send for testing.

When should I be tested for the coronavirus (COVID-19)?

Call your healthcare provider if you:

  • Feel sick with fever, cough or have difficulty breathing.
  • Have been in close contact with a person known or suspected to have COVID-19.
  • Live in or recently traveled from an area with ongoing active spread or for which there are travel alerts.

Your healthcare provider will ask you questions about your symptoms and recent travel history. Your healthcare provider will tell you if you need to be tested for the novel coronavirus, COVID-19 and where to go to be tested.

Management and Treatment

How is COVID-19 treated?

Current ways to manage COVID-19 include using the same support care (e.g., rest, fluids, fever control) and preventive measures used to treat other coronaviruses such as a cold.

At the moment, there is no cure for COVID-19. Scientists are currently developing a vaccine, which has begun being tested in a limited number of people. There are several stages to vaccine testing in humans, each of which takes many months to complete. Scientists first make sure the vaccine is safe, then determine the most effective dose before manufacturing can begin. Typical vaccine development time is 12 to 18 months, but scientists (all working around the world) are hopeful that this time frame will be shortened.

There are no drugs specifically approved to treat COVID-19. Some drugs already approved in the U.S. for other medical conditions are beginning to be given -- as a trial -- to patients infected with COVID-19. These drugs include hydroxycholoroquine (approved to treat malaria, lupus and arthritis) chloroquine (approved to treat malaria) and the antibiotic azithromycin.


How can I prevent getting the novel coronavirus (COVID-19)?

Right now, the best defense to prevent getting COVID-19 is to follow some of the same steps you would take to prevent getting other viruses, such as the common cold or the flu.

  • Wash your hands for at least 20 seconds— especially before eating and preparing food, after using the bathroom, after wiping your nose, and after coming in contact with someone who has a cold.
  • Avoid touching your eyes, nose and mouth to prevent the spread of viruses from your hands.
  • Cover your mouth and nose with a tissue when sneezing and coughing or sneeze and cough into your sleeve. Throw the tissue in the trash. Wash your hands afterward. Never cough or sneeze into your hands!
  • Avoid close contact (within 6 feet) with those who have coughs, colds or are sick. Stay home if you are sick.
  • If you are prone to sickness or have a weakened immune system, stay away from large crowds of people. Follow the directions of your healthcare authorities especially during outbreaks.
  • Clean frequently used surfaces (such as doorknobs and counter tops) with a virus-killing disinfectant.
  • Use hand sanitizers that contain at least 60% alcohol if soap and water are not available.
  • Greet people with a friendly gesture instead of shaking hands.
  • Get enough sleep, eat a healthy diet, drink plenty of liquids and exercise if you are able. These steps will strengthen your immune system and enable you to fight off infections easier.

Should I wear a face mask? Will a face mask help protect me from getting COVID-19?

Masks do help prevent the spread of COVID-19 when worn by people who are actively sick or caring for someone who has COVID-19. Currently, the Centers for Disease Control and Prevention (CDC) does not recommend wearing masks if you are healthy. If you are not sick and do not have symptoms, following the preventive tips listed above (hand washing, cough etiquette and so on) is your best defense.

How deadly is COVID-19?

So far, health officials are seeing mostly mild to moderate infections caused by the novel coronavirus, COVID-19. The death rate from COVID-19 compared with other coronavirus outbreaks remains low at this point in time. The death rate from the SARS outbreak was about 10% of the about 8,000 people who were infected with this virus worldwide. The death rate from the MERS outbreak was about 35% in the nearly 2,500 reported cases. So far, the death rate from the COVID-19 virus about 3%. However, this can change. Scientists are still continuing to learn about this virus including how it’s spreading, how quickly it’s spreading, how severe an illness it’s causing and how it might be treated.


Where can I learn more about COVID-19?

Additional Information

Where do coronaviruses come from?

Coronaviruses are often found in bats, cats and camels. The viruses live in but do not infect the animals. Sometimes these viruses then spread to different animal species. The viruses may change (mutate) as they transfer to other species. Eventually, the virus can jump from animal species and begins to infect humans. In the case of COVID-19, the first people infected in Wuhan, China are thought to have contracted the virus at a food market that sold meat, fish and live animals. Although researchers don’t know exactly how people were infected, they already have evidence that the virus can be spread directly from person to person through close contact.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy