Confirmed Positive: An individual who had a confirmatory viral test performed by way of a throat swab, nose swab or saliva test and that specimen tested positive for SARS-CoV-2, which is the virus that causes COVID-19.

Contact Tracing: A strategy for slowing the spread of disease in which public health workers communicate with infectious people to identify their contacts. They then follow up with those contacts to provide guidance on how to quarantine themselves and what to do if they develop symptoms of disease.

Isolation: The practice of separating people infected with the virus (those who are sick with COVID-19 and those with no symptoms) from people who are not infected. People who are in isolation (usually for 10 days) must stay home until it’s safe for them to be around others. In the home, anyone sick or infected must separate themselves from others by staying in a specific “sick room” or area and using a separate bathroom (if available).

Primary Contact (Close Contact): A person who was within 6 feet of a person infected with COVID-19 for more than 15 minutes, with or without a mask, starting from two days before illness onset (or, for asymptomatic patients, two days prior to positive test result). 

Probable Cases: The Centers for Disease Control and Prevention defines a probable case as a person meeting clinical criteria AND epidemiological evidence with no confirmatory laboratory testing performed for COVID-19; a person meeting presumptive laboratory evidence AND either clinical criteria OR epidemiologic evidence; a person meeting vital records criteria with no confirmatory laboratory testing performed for COVID-19. 

Quarantine: The practice of keeping someone who might have been exposed to COVID-19 away from others. Quarantine helps prevent spread of disease that can occur before a person knows they are sick or if they are infected with the virus without feeling symptoms. People in quarantine must stay home (usually 10 days), separate themselves from others, monitor their health, and follow directions from their state or local health department.

Secondary Contact: A person who was within 6 feet of a primary contact for more than 15 minutes with or without a mask.