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COVID-19 terminology guide from the Douglas County Health Department

By Elizabeth Sayasane 
Douglas County Health Liaison
Back in March, when Gov. J.B. Pritzker announced the stay-at-home order and the precautions the state would take to slow the spread of COVID-19, life seemingly flipped upside down. Communities worked quickly to adapt, but staying up to date on all of the new information coming out every day was difficult, given the sheer volume of it. 

In order to better stay on top of all COVID-19 related information, here is a brief guide to some of the terms and practices being used now.

Coronavirus vs COVID-19: A coronavirus is a large family of viruses which includes COVID-19, the newly discovered infectious disease.


Diagnostic Tests: These tests determine if you currently have COVID-19, whether or not you’re symptomatic. They currently include the following:

Molecular Test: This test is administered either as a nasal or throat swab, or sometimes as a saliva test. It can determine if you are currently infected with COVID-19, with results back in a couple of days.

Antigen Test: This test is administered as a nasal or throat swab and can tell you if you are infected. You can have your results in an hour or less.

Antibody Tests: This test looks for antibodies to determine if you had COVID-19 in the past, even if you presented no symptoms. It’s a blood test and you will have your results within three days. This test does not say if you currently have COVID-19.  

Contact Tracing: This process is used by health departments to prevent the spread of infectious diseases. Tracers let people know they may have been exposed to COVID-19 and should monitor their health for signs and symptoms. Tracing may also involve helping people with such exposure learn how to get tested, and asking people to self-isolate if COVID positive or self-quarantine if they are a close contact.


Isolation: Isolation is meant to separate sick people with a contagious disease from people who are not sick. A positive COVID-19 test results in isolation.

Quarantine: Quarantine restricts the movement of people who were exposed to a contagious disease to see if they become sick.

Social Distancing: To help minimize the spread of coronavirus, people should practice social distancing by staying at least 6 feet (about 2 arms’ length) from people, indoors and outdoors, who are not living in their household. 

Close Contact: This refers to anyone who was within 6 feet of an infected person for 15 minutes or more. Those who are close contacts should quarantine for 14 days from their most recent exposure to the infected person.

Phases: The Restore Illinois plan has five phases meant to help the state overcome the worst of the virus and reopen. The state is currently at Phase 4–which restores much of life, such as group gatherings, travel, and restaurant dining–but with strong safety precautions put in place.


Positivity Rate: This is the percentage of all coronavirus tests performed that are actually positive.

Recovery Rate: This refers to the rate at which people who have been infected and tested positive for COVID-19 have recovered from it.

Confirmed Case: A person who has tested positive for COVID-19, regardless of whether or not they are displaying symptoms, is a confirmed case.

Probable Case: This is a person who is either exhibiting strong COVID-19 symptoms, has had close contact with someone who tested positive or is a probable case themselves, or has traveled to a known high-risk area. 

County Warning Levels: This determines if a county has the warning signs of increased COVID-19 risks. It is assessed in a number of ways, including new cases per 100,000 people and weekly test positivity. The full list of indicators can be found on the DCHD website.

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