The situation of the coronavirus outbreak is changing fast. And news and information about the disease can be overwhelming, not least of which are the many new, confusing, and technical terms being used about the outbreak. Understanding these terms is essential to helping people stay informed and safe—and we take seriously our role in defining and explaining them for you.

In addition to our in-depth articles on pandemic vs. epidemic, quarantine vs. isolation, and COVID-19, we have put together a glossary of some of the most important terms about COVID-19 to keep you up-to-date and in-the-know. We will continue updating the glossary as needed as the situation evolves.

asymptomatic

Asymptomatic means “showing no evidence of disease.”

Just because a person is asymptomatic doesn’t mean they aren’t infected with COVID-19.

CDC

CDC stands for the Centers for Disease Control and Prevention. It is a US federal agency based in Atlanta, Georgia.

According to its mission statement, the CDC:

… works 24/7 to protect America from health, safety and security threats, both foreign and in the U.S. Whether diseases start at home or abroad, are chronic or acute, curable or preventable, human error or deliberate attack, CDC fights disease and supports communities and citizens to do the same.

community spread

Community spread is spread of a disease where the infection source is unknown.

According to the CDC, many sources of COVID-19 are due to exposure to a returned traveler who was infected.

communicable

Communicable means “capable of being easily communicated (spread) or transmitted.” COVID-19 is a communicable disease.

coronavirus

Coronavirus refers to any of various RNA-containing spherical viruses of the family Coronaviridae, including several that cause acute respiratory illnesses.

Notable types of coronavirus are SARS, MERS, and COVID-19. COVID-19 is popularly referred to as (the) coronavirus or corona for short. COVID-19 is referred to as the novel coronavirus because it is a new (novel) virus (i.e., it hasn’t been detected before).

When looked at under a microscope, coronaviruses appear to be surrounded by a spiky array thought to look like a corona, or a crown-like shape, hence the name coronavirus.

COVID-19

COVID-19 is a highly infectious respiratory disease caused by a new coronavirus. The disease was discovered in China in December 2019 and has since spread around the world.

COVID is short for coronavirus disease. The number 19 refers to the fact that the disease was first detected in 2019.

The technical name of the virus that causes COVID-19 is severe acute respiratory syndrome coronavirus 2, abbreviated as SARS-CoV-2.

epidemic

An epidemic is a temporary prevalence of a disease spreading from person to person in a locality where that disease is not permanently prevalent.

epidemiology

Epidemiology is the branch of medicine dealing with the incidence and prevalence of disease in large populations and with detection of the source and cause of epidemics of infectious disease.

An epidemiologist is a person who studies or is an expert in epidemiology.

flatten the curve

Flatten the curve means slowing the spread of an epidemic disease so that the capacity of the healthcare system doesn’t become overwhelmed. The curve represents the number of cases over time, and flattening that curve means preventing a huge surge of new cases in a very short period of time.

Our #FlattenTheCurve graphic is now up on @Wikipedia with proper attribution & a CC-BY-SA licence. Please share far & wide and translate it into any language you can! Details in the thread below. #Covid_19 #COVID2019 #COVID19 #coronavirus Thanks to @XTOTL & @TheSpinoffTV pic.twitter.com/BQop7yWu1Q — Dr Siouxsie Wiles (@SiouxsieW) March 10, 2020

herd immunity

Herd immunity is the immunity or resistance to a particular infection that occurs in a group of people or animals when a very high percentage of individuals have been vaccinated or previously exposed to the infection.

immunity

Immunity is the state of being immune from (“protected from a disease”) or insusceptible to a particular disease; the condition that permits either natural or acquired resistance to disease.

Humans don’t currently have immunity to COVID-19.

immunocompromised

Immunocompromised means having an impaired or compromised immune response; also referred to as immune-compromised or immunodeficient.

incubation period

Incubation period means the period between infection and the appearance of signs of a disease.

isolation

Isolation is the complete separation from others of a person suffering from contagious or infectious disease.

In public health, isolation happens when a person is infected with a communicable disease, and is separated from people who are healthy. This helps stop the spread of disease.

Self-isolation is voluntary isolation. Note that everyday people may use self-isolation when they aren’t infected and are social distancing.

mitigation

Disease mitigation are measures taken to slow the spread of infection. Quarantine, isolation, and social distancing are forms of mitigation.

Washing your hands with soap for at least 20 seconds is one important thing to do to help prevent the spread, or mitigate, COVID-19.

pandemic

A pandemic is a disease prevalent throughout an entire country, continent, or the whole world. A pandemic is an epidemic that has spread over a large area.

The World Health Organization (WHO) specifically uses pandemic to refer to new diseases people do not have immunity for and that have spread worldwide. The WHO has declared the coronavirus outbreak a pandemic.

Pandemic can be both a noun and an adjective (e.g., a pandemic disease).

quarantine

Quarantine is a strict isolation imposed to prevent the spread of disease.

In public health, people are placed in quarantine when they are not currently sick, but have been or may have been exposed to a communicable disease. This helps stop the spread of the disease.

Self-quarantine is when someone isn’t ordered to go into quarantine but chooses to do so out of caution; also called voluntary quarantine.

screening

Screening is examining a person to see if they have a disease. This frequently involves taking their temperature, asking about symptoms, and asking about potential exposures to infected people.

social distancing

Social distancing refers to measures that reduce contact between large groups of people.

Social distancing measures often entail canceling big gatherings (such as conferences, classes, church services, concerts, and sporting events), restricting mass transit and travel, and working from home.

The CDC specifically recommends maintaining a distance of 6 feet (2 meters) between people.

symptom

Symptom is a phenomenon that arises from and accompanies a particular disease or disorder and serves as an indication of it.

Major symptoms of COVID-19 include fever, dry cough, fatigue, and difficulty breathing.

virus

A virus is an infectious agent that replicates only within the cells of living hosts, mainly bacteria, plants, and animals.

Viruses are composed of an RNA or DNA core, a protein coat, and, in more complex types, a surrounding envelope. They are ultramicroscopic, 20 to 300 nanometers (nm) in length. A nanometer is one billionth of a meter. Viruses are also metabolically inert, which is why they only can replicate themselves in cells of living hosts.

COVID-19 spreads through droplets from the mouth and nose of a person with COVID-19 after coughing, sneezing, exhaling, talking, etc.

WHO

WHO stands for the World Health Organization, a United Nations agency based in Geneva, Switzerland.

According to the WHO, its main role is

… to direct and coordinate international health within the United Nations system. Our main areas of work are health systems; health through the life-course; noncommunicable and communicable diseases; preparedness, surveillance and response; and corporate services.

zoonotic

Zoonotic means “relating to any disease of animals communicable to humans.” The noun form is zoonosis.

The source of COVID-19 is believed to be an animal, which makes it a zoonotic disease.

Reported dictionary.com