COVID-19 Definitions and Resources

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By News Team on March 13, 2020

The anxiety people have about the spread of what’s been commonly called “coronavirus” is understandable. It’s new (that’s why it’s called a “novel” coronavirus), so information about its origin, the way it spreads, the way it’s treated and—most importantly—how to stop it from spreading are all still being developed and understood, even by scientists.

Adding to the anxiety is a growing list of words and phrases that non-medical professionals haven’t heard and don’t understand.

We have compiled some of those terms here to help readers better understand developments as they occur—and hopefully decrease some anxiety.

First, the key terms and the difference between the virus and the illness:

  1. Coronavirus refers to a family of viruses, not only the one that is currently in the news; “corona” refers to the shape of the virus when seen under a microscope
  2. Novel coronavirus refers to a newly identified virus in the coronavirus family that has not been seen in humans before
  3. SARS-CoV-2 is the specific strain of coronavirus spreading throughout the world now 
  4. COVID-19 is the name the World Health Organization has given to the illness caused by SARS-CoV-2; it is an abbreviation of "coronavirus disease 2019"


cluster: this term is used when a group of similar health-related events occur in the same geographical area in a short period of time; known as disease clusters, infection clusters or outbreak clusters.
community spread: this is when the disease is present in the community and cannot be linked to a specific index case, such as someone who just returned from overseas. While some cases of coronavirus can be pinpointed to certain trips, associations between people or other events, instances of "community spread" are less specific and harder to trace.
epidemic: a situation where a disease spreads rapidly among many people, and in a higher concentration than normal. It is on a smaller scale, however, than a pandemic. The World Health Organization classified the coronavirus outbreak as a pandemic on March 11, 2020.

facemasks: a physical barrier worn over the nose and mouth by health care workers and people who are ill. Facemasks are not necessary or effective for healthy people to avoid exposure.
influenza: a family of viruses (named influenza A, B, C and D), some of which cause seasonal epidemics of influenza, a respiratory infection that causes fever, sore throat, dry cough, runny nose, headache, muscle and joint pain. Most people recover within a week without medical attention, but vulnerable populations are at risk of severe illness or death. The best way to prevent seasonal influenza is by getting the annual vaccine, and the best way to prevent its spread is through regular, thorough hand washing.
isolation (also see quarantine and social distancing): separating a person who is infected from others in a hospital setting and having the hospital staff use special protective equipment when entering the patient’s room.
MERS (Middle East respiratory syndrome): a viral respiratory illness caused by the coronavirus MERS-CoV.
outbreak: a higher than normal rate of disease in a specific area; outbreaks can be specified as epidemics and pandemics depending on how wide the affective areas are.
pandemic: a worldwide spread of a disease; also known as a "global epidemic." The World Health Organization classified the coronavirus outbreak as a pandemic on March 11, 2020.
person-to-person spread: when a virus is transmitted through close contact between people. This can involve physical contact as well as droplets from coughs and sneezes. It does not refer to diseases that spread from animals to people, or via contaminated surfaces.
public health emergency: an official designation made by a government body, such as a city or a state, to enable access to special funds and resources that have been set aside to address emergencies. The U.S. Department of Health and Human Services can designate a nationwide public health emergency, and the World Health Organization can designate larger global public health emergencies. Governor Ralph Northam declared a state of emergency for Virginia on March 12, 2020. 
quarantine (also see isolation and social distancing): separating a person or group of people from other people, when they are believed to have been exposed to a communicable disease, even if they do not show symptoms
SARS (severe acute respiratory syndrome): a 2002-2003 epidemic caused by the SARS-CoV coronavirus; it killed more than 770 people, mostly in China and Hong Kong.
social distancing (also see isolation and quarantine)when someone sneezes or coughs, the maximum distance infected particles can travel is 3 to 6 feet. Social distancing means voluntarily keeping a distance of 6 feet away from others with this particular virus. 
symptomatic: showing symptoms of an illness or disease. The risk of transmitting most viruses, including SARS-CoV-2 and influenza, is highest when patients are symptomatic, although disease can also be spread when patients are pre-symptomatic, or before they show signs of illness. COVID-19 symptoms include fever, cough and shortness of breath.
virus: a microscopically tiny “parasite” that first attaches itself to our cells, and then gets inside so that it can use our cells’ genetic machinery to "grow" through replication. While they are organic microbes, viruses are not considered “living” since they cannot exist outside a host—in our case, our body’s cells.
vulnerable populations: groups of people who are at higher risk of infection, complications and even death because of their circumstances or illnesses that existed before they came in contact with the virus. These groups include the frail elderly and infants; people with serious chronic medical conditions such as heart disease, diabetes and lung disease; and people whose immune systems are suppressed: people living with chronic illness, especially autoimmune disorders, organ transplant recipients, cancer patients and others.
zoonotic: when a coronavirus can be transmitted, or spread, from animals to humans. This happens rarely, and is believed to have occurred with SARS-CoV-2.


This article was reviewed March 12, 2020 by Thomas M. Kerkering, M.D., F.A.C.P., F.I.D.S.A., Professor of Medicine, Section of Infectious Diseases, Virginia Tech Carilion School of Medicine.

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