Deciphering the terminology you're likely to hear
Asymptomatic
COVID-19 The name of the disease caused by the novel coronavirus, SARS-CoV-2, and is short for “CO-rona-VI-rus D-isease 2019”. Source: WHO
Case fatality rate (CFR) An estimate of the risk of mortality from a contagious disease. The CFR is calculated by dividing the number of deaths caused by a disease by the number of cases of that disease in a given time period. The CFR is time and location-dependent, and many different factors can influence the CFR, such as speed of diagnosis of cases, health system capacity, age and other demographic characteristics, among others. For COVID-19, estimates of the CFR have varied; in China, CFR estimates by province have ranged from <1% to 5.8%. Sources: CDC/Lipsitch et. al./WHO
Close contact A person who may be at risk of a contagious disease because of their proximity or exposure to a known case. Exact definition of close contact differs by disease; for COVID-19, the CDC defines a close contact as anyone who has been within 6 feet of a person infected with the virus for a prolonged period of time, or has had direct contact with the infected person’s secretions. Source: CDC
Community transmission/spread
Infections identified in a given geographic area without a history of travel elsewhere and no connection to a known case.
Contact tracing The process of identifying, assessing, and managing people who have been exposed to a contagious disease to prevent onward transmission. Source: WHO.
Contagious vs. Infectious
Contagious and infectious often cause confusion, as the words overlap in significant ways, yet also have meanings which are in some ways distinct. Contagious is “transmissible by direct or indirect contact with an infected person,” and infectious is “producing or capable of producing infection” and “containing pathogenic agents which may be transmitted.” Both infectious and contagious diseases are caused by bacteria and viruses; they differ in that contagious diseases may be spread by direct or indirect contact.
An ailment such as food poisoning is infectious, it is capable of producing infection, but it is not contagious. The coronavirus, on the other hand, is both contagious and _infectious. Anything that is contagious is automatically also infectious, but the reverse is not true. Both words are frequently used in a figurative manner.
Cordon sanitaire A measure preventing anyone from leaving a defined geographic area, such as a community, region, or country infected by a disease to stop the spread of the disease.
Coronavirus
A family of viruses that cause illness ranging from the common cold to more severe diseases, such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). The novel coronavirus recently discovered has been named SARS-CoV-2 and it causes COVID-19. Source: WHO
Drive through testing Individuals remain in their vehicles, and medical staff in protective gear come to administer the swab test and the swabs are sent to a laboratory for testing.
Droplet transmission/spread A mode of transmission for a contagious disease that involves relatively large, short-range (less than 6 feet) respiratory droplets produced by sneezing, coughing, or talking. Source: CDC
Elective surgeries Procedures that are considered non-urgent and non-essential. During periods of community transmission, CDC is recommending postponing elective procedures, surgeries, and non-urgent outpatient visits. (Source: CDC)
Epidemic An increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area. Source: CDC
Essential activities
(Source: City and County of San Francisco):
Tasks essential to main health and safety, such as obtaining medicine or seeing a doctor;
Getting necessary services or supplies for themselves or their family or household members, such as getting food and supplies, pet food, and getting supplies necessary for staying at home;
Engaging in outdoor activity, such as walking, hiking or running provided that you maintain at least six feet of social distancing;
Performing work providing essential services at an Essential Business or Essential Government function;
Caring for a family member in another household;
Caring for elderly, minors, dependents, person with disabilities, or other vulnerable persons
Essential businesses: (Source: https://sfmayor.org/article/san-francisco-issues-new-public-health-order-requiring-residents-stay-home-except-essential):
Healthcare operations, including home health workers;
Essential Infrastructure, including construction of housing and operation of public transportation and utilities;
Grocery stores, farmers’ markets, food banks, convenience stores;
Businesses that provide necessities of life for economically disadvantaged individuals and shelter facilities;
Pharmacies, health care supply stores, and health care facilities;
Gas stations and auto repair facilities;
Banks;
Garbage collection;
Hardware stores, lumbers, electricians, and other service providers necessary to maintain the safety, sanitation, and essential operation of residences and other essential businesses;
Educational institutions, for the purposes of facilitating distance learning;
Laundromats, dry cleaners, and laundry service providers;
Businesses that ship or deliver groceries, food, and good directly to residences;
Childcare facilities providing services that enable essential employees to go to work;
Roles required for any Essential Business to “maintain basic operations,” which include security, payroll, and similar activities
Essential government functions (Source: City and County of San Francisco) All services needed to ensure the continuing operation of the government agencies and provide for the health, safety and welfare of the public.
Flattening the curve
(Source: CDC)
Fomite
An inanimate object that can be the vehicle for transmission of an infectious agent (e.g., bedding, towels, or surgical instruments). There is evidence that coronavirus spreads via fomites although, this is a less common route of transmission. (Sources: CDC)
The word fomite (which rhymes with ‘toe blight’) is “an object (such as a dish or a doorknob) that may be contaminated with infectious organisms and serve in their transmission.” While this word is infrequently encountered, there has been considerable talk of late about possible surfaces and objects which might harbor infectious substances, and it may well be useful to have this specific word at hand.
Herd Immunity
Home isolation Persons with COVID-19 who have symptoms or laboratory-confirmed COVID-19 who have been directed to stay at home until they are recovered. (Source: https://www.cdc.gov/coronavirus/2019-ncov/hcp/disposition-in-home-patients.html)
Immunity
Immunocompromised
Index case
An index case is “the first documented case of an infectious disease or genetically transmitted condition or mutation in a population, region, or family.” It may also, however, refer to an individual whose has a disease, condition, or mutation that is the first one identified in a population. This second sense is synonymous with index patient. A related term is patient zero, “a person identified as the first to become infected with an illness or disease in an outbreak.”Patient zero is especially used to refer to a person documented as being the first known case of a communicable disease in a particular population or region.
Isolation Separating sick people with a contagious disease from those who are not sick. Source: CDC.
Mitigation
N95 respirator (face mask) Personal protective equipment that is used to protect the wearer from airborne particles and from liquid contaminating the face (Source: https://www.thoracic.org/patients/patient-resources/resources/disposable-respirators.pdf)
Outbreak vs. epidemic and pandemic
An outbreak is “a sudden rise in the incidence of a disease”; an epidemic is “an outbreak of disease that spreads quickly and affects many individuals at the same time”; a pandemic is “an outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population.” An outbreak may become an epidemic if it spreads enough, as an epidemic may likewise become a pandemic.
Negative-pressure rooms Rooms specifically designed for patients with contagious diseases that contain any circulating air in the room and prevent it from being released into any other part of the hospital.
Pandemic
Source: CDC
Quarantine
Source: CDC
R0 / reproductive rate An epidemiologic metric used to describe the contagiousness or transmissibility of infectious agents, which is usually estimated with complex mathematical models developed using various sets of assumptions. It is an estimate of the average number of new cases of a disease that each case generates, at a given point in time. R0 estimates for the virus that causes COVID-19 are around 2 to 3, which is slightly higher than that for seasonal influenza (R0 ~1.2-1.3), but far lower than more contagious diseases such as measles (R0 ~12 - 18). Source: Delamater et. al./Guerra et. al./Biggerstaff et. al.
SARS-CoV-2 The name of the novel coronavirus that causes COVID-19 disease. Source: WHO
Self-quarantine Staying home and away from other people as much as possible after exposure. The idea is to refrain from any contact with other individuals for a period of time (such as two weeks) during the outbreak of a contagious disease usually by remaining in one's home and limiting contact with family members.
Shelter in place All residents must remain at their place of residence, except to conduct essential activities, essential businesses, and essential government functions. (Source: https://sfmayor.org/article/san-francisco-issues-new-public-health-order-requiring-residents-stay-home-except-essential)
Social distancing
Source: CIDRAP
Super-spreader
A super-spreader (also written as superspreader) is “an individual who is highly contagious and capable of transmitting a communicable disease to an unusually large number of uninfected individuals.” The term for the spread of disease by super-spreaders is super-spreading.
Ventilator A device that delivers air into the lungs through a tube that is placed into the mouth or nose and down into the windpipe. (Source: https://www.thoracic.org/patients/patient-resources/resources/mechanical-ventilation.pdf)
Viral shedding The period of time after the virus has replicated in the host and is being emitted.
Virus
Virus has been used to describe something unwelcome for hundreds of years before it became a term for ‘the reason your computer is doing that funny thing that really isn’t funny at all.’ The word comes from classical Latin in which it referred a number of things which might make one wish to wash their hands (venom, pus, and poisonous emanations). The biological sense we all know and fear today (“any of a large group of submicroscopic infectious agents that are usually regarded as nonliving extremely complex molecules, that typically contain a protein coat surrounding an RNA or DNA core of genetic material but no semipermeable membrane, that are capable of growth and multiplication only in living cells, and that cause various important diseases in humans, animals, and plants”) began being used around the beginning of the 20th century. Prior to this virus had such meanings as “venom emitted by a poisonous animal,” and “a morbid corrupting quality in intellectual or moral conditions.”
What is the difference between self-monitoring, self-isolation, and isolation?
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