As a public service, The Inquirer is making this article and other critical public health and safety coverage of the coronavirus available to all readers.

What’s the difference between the coronavirus and COVID-19? Why is it always called the “new” coronavirus? What’s a nonessential business? And why do we keep calling positive tests “presumptive”?

There are a variety of terms and phrases journalists are referencing to describe the spread of the new coronavirus and the mass social disruption it has caused around the world.

Here are some of the terms The Inquirer is using in its coverage and definitions to help better understand the reporting:

Medical terms

The coronavirus — Coronaviruses are a family of viruses common both in people and animals. Sometimes, the viruses can transfer from animals to people, which scientists believe happened in the case of the coronavirus spreading now. It is often called the “new” or “novel” coronavirus, because it hasn’t been widespread before in humans. The technical term is SARS-CoV-2, not to be confused with SARS-CoV, the virus that contributed to a global outbreak in 2003.

COVID-19 — The disease caused by the new coronavirus. COVID-19 is marked by symptoms that can include fever, dry cough, and shortness of breath.

Confirmed positive case — A case of the new coronavirus that has been tested and confirmed by the U.S. Centers for Disease Control and Prevention or the state Department of Health.

Presumptive positive case — A case of the new coronavirus that has been tested by a local or commercial laboratory but has not been confirmed by the CDC or the state.

Epidemic — An outbreak of disease in a community at a particular time.

Pandemic — An epidemic that spreads worldwide, often because the disease is new and there is little to no immunity.

Isolation — The Pennsylvania Department of Health defines isolation as someone who is sick with COVID-19 staying at home or at a hospital and getting medical care.

Quarantine — The Pennsylvania Department of Health defines quarantine as a person who has been exposed to someone who has COVID-19 and is at home to limit exposure to the community.

Self-quarantine — To refrain from contact with others during an outbreak of disease.

Community spread/ transmission — The phrase used to describe when a disease is spread through a community and there are cases where the exposure is unknown. For example, known exposure would be if someone came into contact with another person confirmed to have a disease or if they traveled to an area heavily affected.

Incubation period — The amount of time between exposure to a virus and the first showing of symptoms. The incubation period of the new coronavirus is two to 14 days.

Fatality rate — The share of those infected who die. Scientists and public health officials have estimated the new coronavirus has a fatality rate of about 1%, though rates are higher in places where large numbers of patients have overwhelmed health care systems. The actual rate isn’t yet known, as asymptomatic patients typically don’t seek treatment and therefore aren’t counted as survivors while calculating fatalities.

Patients — Generally considered, in this case, as someone who is being treated for the new coronavirus.

Persons Under Investigation (PUI) — The number of people who have been tested for the new coronavirus in a geographic area.

Asymptomatic — Used to describe someone who is not showing symptoms of COVID-19. Scientists believe the new coronavirus can and does spread through asymptomatic people.

Outbreak — A sudden start, in this case, of a disease.

Epidemiologist — A scientist who studies diseases within certain populations and works to understand how, why, and where they spread.

High-risk — Someone who is at high risk of getting the coronavirus or of becoming gravely ill if they contracted it is generally determined by age and/ or underlying health risks, including people whose immune systems are compromised.

Ventilator — A machine that blows oxygenated air into a person’s lungs because they unable to breathe sufficiently on their own. Some have questioned whether hospitals are equipped with enough ventilators to handle a surge of patients whose respiratory systems are failing as a result of the virus.

This undated photo provided by Vyaire Medical, Inc. shows an Avea CVS ventilator. U.S. hospitals bracing for a possible onslaught of coronavirus patients with pneumonia and other breathing difficulties could face a critical shortage of mechanical ventilators.
/ AP
This undated photo provided by Vyaire Medical, Inc. shows an Avea CVS ventilator. U.S. hospitals bracing for a possible onslaught of coronavirus patients with pneumonia and other breathing difficulties could face a critical shortage of mechanical ventilators.

ARDS — Acute respiratory distress syndrome. The disease is a severe complication that could arise for 1 in 100 people who contract the new coronavirus. ARDS kills 30 to 40% of the people who get it and survivors require being on a ventilator for weeks.

Influenza/flu — A viral infection that attacks the respiratory system and can cause mild to severe illness. Common symptoms include fever, cough, congestion, and runny nose.

1918 flu — An influenza pandemic that was abnormally deadly. It infected 500 million people globally, which at the time was more than a quarter of the world. The 1918 pandemic is considered the deadliest in history.

Vaccine — A substance used to provide immunity to a disease. Experts say it could be more than a year before a vaccine for the new coronavirus is ready for distribution.

Faraz Zaidi, project manager, does a western blot analysis to compare different versions of the coronavirus vaccine at the Wistar Institute.
MONICA HERNDON / Staff Photographer
Faraz Zaidi, project manager, does a western blot analysis to compare different versions of the coronavirus vaccine at the Wistar Institute.

Clinical trial — Research studies performed using people. Clinical trials happen during the research and development phase of new drugs and vaccines.

Social and governmental terms

Flattening the curve — This concept refers to shortening and lengthening the curve, or the number of cases of a disease present represented on a graph. The idea is that lengthening the curve through social distancing can keep the number of cases at any one time low enough for the health-care system to manage.

Social distancing — The concept of restricting behavior and limiting in-person interactions to slow the spread of disease. The tactic is often used to keep a fast-spreading infection from overwhelming health-care systems.

Contact tracing — The method by which public health officials trace with whom an infected person interacted. The process is used to determine who might be at-risk of contracting the virus after coming into contact with a person infected.

Shutdown recommendation — A guidance from a government agency to close a business or other entity that can’t or won’t be enforced.

Shutdown order — A requirement from a government agency to close a business or other entity that may be enforced through a variety of measures, including citations and prosecution.

Shelter-in-place order — A directive from the government to stay inside the place one occupies. The orders are often used during natural disasters to keep people inside their homes or workplaces. The first widespread shelter-in-place order in the U.S. was issued in the San Francisco Bay Area on March 16 and affected 7 million people.

State of emergency — A declaration by a local, state or federal government that allows for that government to take steps to mitigate an emergency, including diverting funding and exercising new powers.

Essential business — Officials in Pennsylvania moved to shut down all nonessential businesses statewide on March 16. Essential services and sectors, according to the state of Pennsylvania, include but are not limited to: food processing, agriculture, industrial manufacturing, feed mills, construction, trash collection, grocery and household goods (including convenience stores), home repair/hardware and auto repair, pharmacy and other medical facilities, biomedical and health care, post offices and shipping outlets, insurance, banks, gas stations, laundromats, veterinary clinics and pet stores, warehousing, storage, and distribution, public transportation, and hotel and commercial lodging.

The City of Philadelphia issued its own guidelines, also including as essential businesses any commercial establishment that sells the following: frozen products; non-specialized stores of computers, telecommunications equipment, audio and video consumer electronics, household appliances; IT and telecommunication equipment; hardware, paint, flat glass; electrical, plumbing and heating material; automotive fuel; domestic fuel; sanitary equipment; personal hygiene products medication not requiring medical prescription; medical and orthopedic equipment; optics and photography equipment; and soaps and detergents.

Nonessential business — According to the state of Pennsylvania, nonessential businesses include public-facing industries such as entertainment, hospitality, and recreation facilities, including but not limited to community and recreation centers; gyms, including yoga, barre, and spin facilities; hair salons and barber shops, nail salons and spas; casinos; concert venues; theaters; sporting event venues and golf courses; retail facilities, including shopping malls except for pharmacy or other health-care facilities within retail operations.

Life-sustaining business - Pennsylvania officials on March 19 began to use the phrase “life-sustaining businesses” to describe entities that could remain open. This is a smaller pool than “essential” businesses and does not include daycares, laundromats, car dealers, lawn and garden stores, specialty food stores, or offices that provide legal or accounting services. A full list of life-sustaining businesses can be found here.

A sign of closure hangs outside of the Philadelphia Film Society in Center City .
HEATHER KHALIFA / Staff Photographer
A sign of closure hangs outside of the Philadelphia Film Society in Center City .

Containment area or containment zone — A geographic area where an outbreak has taken place and aggressive social distancing measures have been ordered by government officials to keep the spread of the virus contained in the zone. The first containment area in the United States was established in New Rochelle, N.Y.

Groups, agencies and organizations

WHO — The World Health Organization. The agency falls under the umbrella of the United Nations.

CDC — The Centers for Disease Control and Prevention, or the federal agency that oversees public health. The CDC is playing a wide variety of roles during the spread of the new coronavirus, including confirming positive cases and making recommendations related to how Americans should respond.

White House Coronavirus Task Force — A group of top health officials chaired by Vice President Mike Pence. Among its members are Dr. Robert R. Redfield, director of the CDC, and Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, who has become something of a spokesperson for the group.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, speaks during a press briefing with the coronavirus task force.
Evan Vucci / AP
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, speaks during a press briefing with the coronavirus task force.

State Department of Health — This refers to a state’s own Department of Health, separate from the CDC or other federal entities. State Departments of Health are doing much of the testing for the new coronavirus to determine presumptive positive cases. Before commercial laboratories were authorized to conduct such tests, state labs were generally the only testing facilities outside the CDC. State departments of health are also coordinating mitigation tactics, tracking patients and their contacts, and making social distancing recommendations.

City/county Health Department — Some cities and counties have their own health departments that play similar roles to the state departments of health, but are more localized. Philadelphia has a city Department of Health, and Bucks, Chester and Montgomery Counties have county Departments of Health.