Coronavirus (COVID-19): ONS Infection Survey – characteristics data for Scotland – 22 June 2022

The article is based on findings from the Office for National Statistics (ONS) COVID-19 Infection Survey.

The COVID-19 Infection Survey aims to measure:

• how many people test positive for COVID-19 infection at a given point in time, regardless of whether they report experiencing coronavirus symptoms
• the average number of new infections per week over the course of the study
• the number of people who test positive for antibodies, to indicate how many people are ever likely to have had the infection or have been vaccinated

The Office for National Statistics (ONS) publish analysis of the characteristics of those testing positive for COVID-19 in England, Wales, Northern Ireland, Scotland and the UK on their website.

The underlying data displayed in the charts in this publication is available in the reference tables on the ONS website.

If you have any feedback on the content or frequency of this publication please contact covidinfectionsurvey@gov.scot. 

All results are provisional and subject to revision.

Main points

In Scotland, 67.1% of people living in private residential households who tested positive for COVID-19 with a strong positive test between 1 March and 2 June 2022 reported having any symptoms (95% confidence interval: 65.5% to 68.7%).

The most commonly experienced symptoms in those living in private residential households in Scotland were a cough, a sore throat, a headache and fatigue or weakness.

Symptom profile of people who tested positive for COVID-19 in Scotland

This section presents analysis based on people who tested positive for coronavirus (COVID-19) with a strong positive test (Cycle threshold (Ct) value less than 30 (see note 2)). It considers what percentage of these people reported individual and groups of symptoms within 35 days of the first positive test in each infection episode. 

The average viral load of the people testing positive for COVID-19 also affects whether they are likely to report symptoms. The ONS has seen that the viral load of strong positive results increased during January 2022, as measured by decreases in the average Ct value. This will also affect the prevalence of symptoms within these strong positive cases.

Individuals taking part in the survey were asked at each visit whether they had experienced a range of possible symptoms in the seven days before they were tested, and also separately whether they felt that they had symptoms compatible with COVID-19 infection in the last seven days (see notes 1, 3 and 6). This analysis considers all symptoms reported at visits within 35 days of the first positive test of the episode. This includes symptoms reported even when there is a negative test within this timeframe or a positive test with a higher Ct value (see note 7). 

Symptoms data for the UK is presented in the bulletin published on the ONS website on 22 June 2022, along with more details on the methods used in this analysis. The ONS bulletin also includes UK level analysis of reinfections and risk factors of reinfections.

At the UK level, 59.7% (95% confidence interval: 58.1% to 61.3%) of people testing positive for COVID-19 with a strong positive test reported any specific symptoms or any other self-reported symptoms compatible with COVID-19 in May 2022. 

In Scotland, 67.1% of people living in private residential households who tested positive for COVID-19 with a strong positive test between 1 March and 2 June 2022 reported having any symptoms (95% confidence interval: 65.5% to 68.7%). In the same period, 32.9% of people who tested positive for COVID-19 with a strong positive did not report symptoms (95% confidence interval: 31.3% to 34.5%) (Figure 1).

As shown by Figure 1, the percentages of people testing positive who reported each group of symptoms are similar for each country between 1 March and 2 June 2022.

Because of smaller sample sizes in Wales, Northern Ireland and Scotland in comparison with England, the confidence intervals are wider indicating higher uncertainty (see notes 4 and 5).

Figure 1: Unweighted percentage of people with a strong positive test for COVID-19 who reported having any symptoms and no symptoms, in each of the four nations of the UK, from 1 March to 2 June 2022, including 95% confidence intervals
 

The most commonly experienced symptoms in those living in private residential households in Scotland were a cough, a sore throat, a headache and fatigue or weakness (Figure 2).

Figure 2: Unweighted percentage of people with a strong positive test for COVID-19, by symptom, from 1 March to 2 June 2022 in Scotland, including 95% confidence intervals

  

Methodology and further information

1. The population relates to those living in private residential households aged two years and over, and excludes those in hospitals, care homes and/or other communal establishments. 
2. The symptom profile analysis looks at symptoms associated with positive episodes (including repeated positive tests) with any Ct value in the episode below 30. This is to exclude the possibility that symptoms are not identified when an individual tests positive as it is very early on or later on in the infection. 
3. Symptoms are self-reported and were not professionally diagnosed.
4. Because of the relatively small number of tests and a low number of positives in the sample, confidence intervals are wide and therefore results should be interpreted with caution. 
5. Estimates are provided with 95% confidence intervals to indicate the level of uncertainty around them. A confidence interval gives an indication of the degree of uncertainty of an estimate, showing the precision of a sample estimate. The 95% confidence intervals are calculated so that if we repeated the study many times, 95% of the time the true unknown value would lie between the lower and upper confidence limits. A wider interval indicates more uncertainty in the estimate.
6. The symptoms respondents were asked to report are: fever, muscle ache (myalgia), fatigue (weakness or tiredness), sore throat, cough, shortness of breath, headache, nausea or vomiting, abdominal pain, diarrhoea, loss of taste or loss of smell. 
7. Positive episodes are defined as "a new positive test 120 days or more after an initial first positive test and following a previous negative test, or, if within 120 days, a subsequent positive test following four consecutive negative tests".

More information about the COVID-19 Infection Survey in Scotland can be found on the information page on the Scottish Government website, and previous COVID-19 Infection Survey data for Scotland can be found in this collection.

The latest analysis on how often individuals are reporting social contact with other people outside their own household, either socially distanced or physical contact, was published on 11 May 2022 on the Scottish Government website and the ONS website.