5.6 Case definitions and symptomology

5.6.1 Definition of a confirmed COVID-19 case

5.6.2 Definition of a possible COVID-19 case

5.6.3 Vaccine definition


Case definitions for COVID-19 have been widely used throughout the course of the pandemic and these will continue to be used going forward. These align with case definitions in Public Health Scotland guidance.

Establishing which symptoms are a result of COVID-19 and which symptoms are a result of another respiratory virus is often not possible.  Respiratory testing is the only way to identify the causative pathogen.

The case definitions being used across the UK reflects current understanding from the epidemiology available and may be subject to change.  Case definitions can be found below.

5.6.1 Definition of a confirmed COVID-19 case

A person with laboratory confirmed detection of SARS-CoV-2 by PCR in a clinical specimen OR a positive LFD test for SARS-CoV-2.

Things to note:


5.6.2 Definition of a possible COVID-19 case

Persons with any of the symptoms of a respiratory infection and with a high temperature or not well enough to go to work or carry out normal activities, should be considered a possible case.

Symptoms of COVID-19, flu and common respiratory infections include:

A wide variety of additional clinical signs and symptoms have also been associated with COVID-19. Fever may not be reported in all symptomatic people and cases may also be asymptomatic. It is important to take into account atypical and non-specific presentations in older people with frailty, those with pre-existing conditions and those who are immunocompromised. (further information on presentations and management of COVID-19 in older people and Scottish Government and Appendix 1 :Think COVID:Covid-19 Assessment in the Older Adult - Checklist).

Individuals must be assessed for bacterial sepsis or other causes of symptoms as appropriate.


5.6.3 Vaccine Definition

Vaccination status impacts on IPC only for adults and is defined as;

Fully vaccinated: An adult (18 years and 4 months or older) who has had three doses of MHRA approved vaccines; either through completing a two-dose course of approved vaccine and received a booster, or three doses of an approved vaccine (e.g. in the case of someone who is immunocompromised), at least 14 days prior to their contact with the index case, where day 1 is the day of the most recent vaccination.

Where an individual has been fully vaccinated (as defined above) while participating in a formally approved COVID-19 vaccine clinical trial they should be treated as those who are fully vaccinated.