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The COVID-19 Infection Survey (CIS) aims to establish:

  • how many people have the infection over a given time
  • how many new cases occur over a given period
  • how many people have antibodies to COVID-19

The survey will help track the extent of infection and transmission of COVID-19 among people in private residences, referred to as the community population.

Proportion of people in Wales who had COVID-19

For the week of 19 August to 25 August 2020 it is estimated that an average of 0.05% of the community population had COVID-19 (95% credible interval: 0.01% to 0.11%).

This equates to around 1 in 2,200 individuals (95% credible interval: 1 in 8,300 to 1 in 900), or an estimated 1,400 people in total (credible interval: 400 to 3,500).

Data suggest that the rate has been relatively stable over the most recent 6 weeks.

Chart showing the official estimates for the percentage of people testing positive through nose and throat swabs from the 29th July to 25th August 2020. The estimates have been relatively stable over the period, at between 0.04% and 0.05%.

Chart title amended 18 September 2020 

Quality and methodology information

The results are based on nose and throat swabs and blood samples provided by participants to the study. As well as looking at incidence overall, the survey will be used to examine the characteristics of those testing positive for COVID-19 and the extent to which those infected experience symptoms.

Fieldwork started in Wales on 29 June 2020. It is important to note that there is a significant degree of uncertainty with the estimates. This is because, despite a large sample of participants, the number of positive cases identified is small. Estimates are provided with 95% credible intervals to indicate the range within which we may be confident the true figure lies.

The results are for private households only and do not apply to those in hospitals, care homes or other institutional settings.

The Office for National Statistics (ONS) publishes weekly statistical bulletins and references tables, including results for England and Wales, on its website.

The estimates are based on statistical modelling. ONS produces two series’, one giving the official weekly reported estimates and one giving a 6-week series produced by the latest model. The latest model provides the most reliable estimate for the latest week. However, ONS advises that when making comparisons over time the previously reported weekly estimates should be used. These weekly estimates are used in Chart 1.

Further information about quality and methodology can be found on the ONS website.

Well-being of Future Generations Act (WFG)

The Well-being of Future Generations Act 2015 is about improving the social, economic, environmental and cultural well-being of Wales. The Act puts in place seven well-being goals for Wales. These are for a more equal, prosperous, resilient, healthier and globally responsible Wales, with cohesive communities and a vibrant culture and thriving Welsh language. Under section (10)(1) of the Act, the Welsh Ministers must (a) publish indicators (“national indicators”) that must be applied for the purpose of measuring progress towards the achievement of the Well-being goals, and (b) lay a copy of the national indicators before the National Assembly. The 46 national indicators were laid in March 2016.

Information on the indicators, along with narratives for each of the wellbeing goals and associated technical information is available in the Well-being of Wales report.

Further information on the Well-being of Future Generations (Wales) Act 2015.

The statistics included in this release could also provide supporting narrative to the national indicators and be used by public services boards in relation to their local well-being assessments and local wellbeing plans.

Contact details

Statistician: Ryan Pike
Telephone: 0300 025 6415

Media: 0300 025 8099

SFR 133/2020