Enhanced Surveillance of COVID-19 in Scotland

This dataset shows the latest results of the Public Health Scotland (PHS) serology surveillance programme. The PHS serology surveillance programme uses existing blood samples within community healthcare and other settings to estimate the proportion of people who have antibodies to coronavirus ("seroprevalence") in the general population of Scotland and to see if this changes over time. Antibodies can be used to identify individuals who have had COVID-19 infection in the past or have developed antibodies as a result of vaccination.

This data is also available on the Enhanced Surveillance of Covid-19 in Scotland Dashboard along with detailed commentary and background information on interpreting the data. The dashboard can be accessed from the Enhanced Surveillance of Covid-19 in Scotland publication page. The date of the next release can be found on our list of forthcoming publications. Additional data sources relating to this topic area are provided in the Links section of the Metadata below. Information on COVID-19, including stay at home advice for people who are self-isolating and their households, can be found on NHS Inform.

Revisions have been made to our antenatal data: from week beginning 7th June 2021 (ISO week 23 of 2021), we can detect which antibodies are from vaccination and which are from infection (+/- vaccination). These changes can be seen in the dashboard publications from 10th November 2021 onwards. More detail regarding these changes can be found in the notes section of the dashboard.

Data and Resources

Additional Info

Field Value
Source Primary Care, SNBTS and Antenatal
Author Public Health Scotland
Version 1.0
Last Updated August 3, 2022, 12:01 (BST)
Created April 14, 2021, 11:34 (BST)
Contact Address Public Health Scotland, Gyle Square, 1 South Gyle Crescent, Edinburgh EH12 9EB
Subject COVID-19, Seroprevalence
Frequency Weekly
Time frame of data and timeliness The time lag between collection, validation, analysis and reporting of samples is typically 2-4 weeks.
Coverage Since week commencing 20 April, blood samples, originally collected for other clinical reasons in community healthcare settings, have been obtained from regional biochemistry laboratories in six NHS Boards: Greater Glasgow and Clyde (GGC), Grampian, Highland, Lanarkshire, Lothian, and Tayside. Fife, Shetland and Forth Valley began submitting samples from week commencing 15 June. Dumfries and Galloway began submitting from week commencing 29 June and Orkney from week commencing 13 July. Approximately 700 samples are now collected each week. Laboratories select specific numbers of samples by age and sex to achieve a representative sample based on the age and sex structure of the general population in that NHS board. Samples are anonymised and sent to the Scottish Microbiology Reference Laboratory in Inverness for testing. Seroprevalence rates have been adjusted for the accuracy of the antibody test and weighted to the population structure. Samples originally collected from blood donors have been retrieved and tested by the Scottish National Blood Transfusion Service (SNBTS) since week commencing 29 June. Approximately 500 samples are collected each week from 12 NHS Boards (excluding Shetland and Western Isles). Seroprevalence rates have been adjusted for the accuracy of the antibody test and weighted to the population structure. Antenatal samples, originally collected from pregnant women at their antenatal booking appointment (approximately week 12 of pregnancy) and sent for Down’s Syndrome screening at the Western General Hospital, Edinburgh, have been anonymised and sent to NHS Lanarkshire for testing. Approximately 600 samples are collected each week from across Scotland. Seroprevalence rates have been adjusted for the accuracy of the antibody test and weighted to the age structure of a reference population (maternities in Scotland in 2019-20).
Completeness Primary Care residual samples: Six NHS boards (NHS Grampian, NHS Greater Glasgow & Clyde, NHS Highland, NHS Lanarkshire, NHS Lothian and NHS Tayside) have provided weekly data since the beginning of the programme. An additional five NHS boards (NHS Dumfries & Galloway, NHS Fife, NHS Forth Valley, NHS Orkney and NHS Shetland) have joined the programme at later dates, and therefore may not have complete data available for all weeks. Where the patient`s age or sex was missing, results have been omitted from the relevant age group or sex breakdown. Blood donor residual samples: Samples are from blood donation clinics, the locations of which vary from week to week. Consistent weekly data for each NHS board are therefore not available. Where the patient`s age or sex was missing, results have been omitted from the relevant age group or sex breakdown. Antenatal residual samples: Consistent weekly data for each NHS Board are not available. Where the patient's age was missing, results have been omitted from the relevant age group breakdown NHS boards with 5-weekly totals of less than 10 samples were excluded from the analysis.
Continuity of data Weekly data from community healthcare samples is presented from week commencing 20 April from six NHS Boards: Greater Glasgow and Clyde (GGC), Grampian, Highland, Lanarkshire, Lothian, and Tayside. Fife, Shetland and Forth Valley began submitting samples from week commencing 15 June. Dumfries and Galloway began submitting from week commencing 29 June and Orkney from week commencing 13 July. Primary care samples have been tested using the Diasorin assay. Samples originally collected from blood donors have been retrieved and tested by the Scottish National Blood Transfusion Service (SNBTS) since week commencing 29 June. The blood donor samples have been tested using the Abbott assay up to and including ISO week 42 (week commencing 12th October 2020) and the Eurolmmun assay from week 43 (week commencing 19th October 2020) onwards. Antenatal samples have been tested using the Roche assay. The sensitivity (proportion of true positives that have been correctly identified) and specificity (proportion of true negatives that have been correctly identified) varies between assays. The seroprevalence estimates have been adjusted for the sensitivity and specificity of these assays. The primary care samples have been tested using a new Diasorin assay from ISO week 15 (week commencing 12th April 2021) onwards. With the transition to the new Diasorin assay, it is not possible to calculate 5-weekly rolling estimates until 5 weeks of data have accumulated. Data for ISO weeks 15 to 18 of 2021 are therefore weekly rather than 5-weekly rolling estimates. Data for these weeks have been adjusted for the sensitivity and specificity of the new assay, but have not been weighted to the general population.
Concepts and definitions Please see Notes on the Enhanced Surveillance of COVID-19 in Scotland dashboard (Link 1) and PHS`s Enhanced Surveillance of COVID-19 in Scotland publication (Link 2).
Disclosure The PHS protocol on Statistical Disclosure Protocol is followed.
Revision statement These data are not subject to planned major revisions. Revisions were made to our methods in July and August 2021 to improve the accuracy of our adjustments for SNBTS and Primary Care data, respectively. As a result, a number of previously published seroprevalence estimates have been revised; these are marked in red font in the downloadable data file on our dashboard. The vast majority of revisions for both SNBTS (80%; 171/215) and Primary Care (93%; 127/136) involve changes of less than 1% and have had no bearing on the interpretation of our seroprevalence trends to date. The new methods and revised figures were included in our dashboard and publications from 28 July 2021 onwards for SNBTS and 11 August 2021 onwards for Primary Care. Revisions have been made to our antenatal data to correct retrospectively for missing data in the week commencing August 30 2021. As a result, previously published antenatal seroprevalence estimates for the rolling 5-week periods that included this week (i.e. the estimates for the 5-week periods up to and including weeks beginning August 30 2021 through to September 20 2021) have undergone minor adjustments. The revised figures were included in our dashboard and publications from 27 October 2021 onwards. More detail regarding these changes can be found in the dashboard notes section.
Official statistics designation Management Information Statistics
Relevance and key uses of the statistics The serology work stream aims to estimate the proportion of people who have antibodies to coronavirus (“seroprevalence”) in the general population of Scotland and provides the ability to detect asymptomatic and mild infections and to see if this changes over time. The data are used to describe the current impact and the severity of COVID-19 in Scotland. Such information allows comparison with prior influenza seasons and with current activity across the UK, Europe and globally.
Format csv
Language English
Links

Enhanced Surveillance Dashboard

PHS Enhanced Surveillance Publication

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