Glossary and definitions: COVID-19 terminology

General COVID-19 terms


COVID-19 is the common name for the novel coronavirus disease 2019, which is caused by the SARS-CoV-2 virus.

Check in at venues

Checking in is a way to help contact tracing officers to be able to contact all people at risk of catching COVID-19 from a  confirmed case. In Queensland, businesses are required to keep electronic records of the contact details of all guests and staff (excluding takeaway and delivery).

Cluster or outbreak

A cluster or outbreak is the occurrence of several cases of COVID-19 in a specific place or group of people (who do not reside in the same household) over a given period of time.

If the illness is associated with a common source (such as an event or within a community) it is referred to as an outbreak. If the common source of the infection is suspected but not yet established it is referred to as a cluster.

Contact tracing

The process of talking to a confirmed case of COVID-19 to determine where they have been and who they have had contact with.

This is to identify who is at risk of catching the disease from the case. Wherever possible, people identified as close contacts will be notified of their risk of acquiring the disease and will be asked to quarantine for 14 days from their last exposure to the case. When the contact tracing officers are unable to obtain contact details of close contacts or there is significant risk of casual contact, a public health alert will be issued on our website and via the media.

Genome sequencing

Genome sequencing uses a person's positive COVID-19 sample and compares it to other cases to determine the variant of COVID-19 and whether there are links to other cases.


Hotspots are places in Australia or safe travel zone countries where health officials have found a lot of people with COVID-19, or places that are at risk of a lot of COVID-19 infections. Hotspots are legally listed so that people travelling from those high-risk areas into Queensland can be identified.

Restrictions will apply to persons who have been in a hotspot in the previous 14 days or since the start date identified for the hotspot (whichever is shorter). The start date identified can be earlier than the date when the hotspot was declared. This is because the start date for the hotspot is when the risk of COVID-19 transmission started.


Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus that causes the respiratory illness COVID-19.

Social (physical) distancing

Staying a safe distance from others to prevent the spread of the virus.

This includes:

  • staying at least 1.5 metres from others
  • avoiding physical greetings such as handshakes, hugs and kisses.


A physical sign of illness which suggests that you may have COVID-19 such as a cough, fever, shortness of breath, sore throat, runny nose or loss of smell or taste.

Case definitions

Close contact

A close contact is a person who has:

  • had face-to-face contact for any amount of time or shared a closed space for at least 1 hour with a confirmed case during their infectious period
  • been to a venue or location where the risk of transmission is considered high based on public health assessment
  • been identified by public health authorities to be at high risk for developing COVID-19 as they have or may have been in contact with someone with COVID-19, for example in a school or other institutional setting.

The local public health unit will tell you if you have been deemed a close contact of someone who has COVID-19. They may direct you to quarantine for 14 days. If you get sick with any COVID-19 symptoms during that period, even mild, get tested immediately.

Casual contact

Casual contacts are people who may have been at the same location as a confirmed case of COVID-19 in their infectious period but has not had face-to-face or has not shared a closed space for more than 1 hour.

Community transmission

A confirmed case of COVID-19 where the source of infection is unknown, but was presumably infected in the local community. May also be called locally acquired—no known contact.

Historical case

A historical case is someone who is suspected of having had a case of COVID-19 but was not diagnosed with a PCR test. These cases are generally identified through serology testing which may be used when investigating an outbreak.

Identified date

The identified date for an interstate exposure venue is the date and time that determines if you need to quarantine under the Interstate Exposure Venues Direction. This includes people arriving into Queensland and those already in Queensland.

Interstate exposure venue

An interstate exposure venue is identified by another state, territory or Queensland safe travel zone country and published on the Queensland Health website. This is a place where a person who has been diagnosed with COVID-19 has been.

See a list of interstate exposure venues on the Queensland Health website.

See the Interstate Exposure Venues Direction for more information.

Source of infection (transmission source)

The source of infection is how someone who has been diagnosed with COVID-19 is thought to have caught the virus. We use the following classifications for sources of infection:

  • Overseas acquired: the person was infected while in another country
  • Interstate acquired: the person was infected in another Australian state
  • Locally acquired—close contact with confirmed case: the person was infected in Queensland, but the source of the infection has been identified, for example a household or workplace contact
  • Locally acquired—no known contact (may also be called community transmission): the person was infected in Queensland and the source of the infection hasn't been found through contact tracing and further testing.

Quarantine and isolation



Quarantine is when people who are well and may have been in contact with someone with COVID-19 have to stay away from others to stop the spread of COVID-19. The quarantine period is 14 days, which is the standard incubation period (the time between getting the virus and showing symptoms) for COVID-19.  Read more about quarantine.



Isolation is when people who have COVID-19 symptoms or are infectious have to stay away from other people to stop the spread of COVID-19. People who have been tested for COVID-19 and are awaiting their test results are required to isolate at home until they get a negative result.

People who have been to a low risk exposure venue and develop COVID-19 symptoms are required to get tested and isolate.

People diagnosed with COVID-19 are currently required to be managed in a hospital setting.

Quarantine at government arranged accommodation (hotel or supervised quarantine)

Quarantine at government arranged accommodation is when people at high risk of having contact with a COVID-19 case are required to stay in a hotel or other accommodation provided by the government to ensure they do not come into contact with other people in the community.

This is due to the significant health risk that cannot be appropriately managed at other residences or accommodation providers. If the mandatory quarantine requirements are not strictly followed and people mix more easily in the community, there is unacceptable risk of COVID-19 transmission in the community.

Quarantine at home (or self-quarantine)

Quarantine at home means a person must stay at their residence (or accommodation if travelling) usually for 14 days to prevent the spread of COVID-19.

They must not leave their residence unless it is to get essential medical care, to avoid injury or illness, or to escape a risk of harm. They should not allow anyone into their place of quarantine unless they live there or need to enter to provide emergency or medical care.


Tests for COVID-19 aim to detect the virus SARS-CoV-2, or an immune response to SARS-CoV-2.

PCR testing

Testing for COVID-19 is done using a PCR (polymerase chain reaction) test. This involves a swab of the nose and throat. The swab sample is then sent to the laboratory to detect the genetic material from SARS-CoV-2, (the virus that causes COVID-19).

Asymptomatic testing

When a person is tested for a disease without having any symptoms of the disease (such as a fever, cough or shortness of breath).

Serology testing

Serology testing is testing of a blood sample to measure antibodies to a disease. People develop antibodies as part of an immune response to a virus. Antibodies take time to develop (from days to weeks) and so serology testing cannot be relied on to diagnose an active infection. It can be used under certain circumstances for the diagnosis of a past COVID-19 infection.

Wastewater surveillance testing

Wastewater surveillance looks for undetected cases of the virus by taking samples from wastewater (sewage) and testing for SARS-CoV-2, the virus that causes COVID-19. This helps determine where in our state there might be people with a current COVID-19 infection, or who have been infected in the recent past.

People who currently have or have recently had coronavirus (COVID-19) may shed fragments of the virus. These fragments can enter the wastewater system via toilets, sinks and drains. These viral fragments are not infectious and there is no risk to public water supplies.