Table of contents
- Main points
- Coronavirus (COVID-19) cases by age and symptoms at time of positive test
- Coronavirus (COVID-19) cases by ethnicity
- Coronavirus (COVID-19) cases by deprivation
- Positive Coronavirus (COVID-19) tests by region
- Positive Coronavirus (COVID-19) tests by special educational needs (SEN)
- Number of reported positives
- Testing rate
- Data sources and quality
- Future developments
- Related links
1. Main points
Both primary school-aged and secondary school-aged pupils were more likely to have a positive coronavirus (COVID-19) test in the spring 2022 term (16.1% and 27.0%, respectively) compared to the autumn 2021 term (14.2% and 21.5%, respectively).
Changes to the testing guidance in the second half of the spring 2022 term mean that it is likely that a lower proportion of infections were recorded in the Test and Trace data, potentially causing the increase in infections between the two terms to be underestimated.
White British pupils had the largest proportion of their population with a positive coronavirus (COVID-19) test in both the spring 2022 term (18.6% for primary age and 29.8% for secondary age) and the autumn 2021 term (16.8% and 25.1%).
In the spring 2022 term, primary school-aged and secondary school-aged pupils living in more deprived areas were less likely to have a positive coronavirus (COVID-19) test; in the most deprived areas 11.8% of primary pupils and 21.6% of secondary-aged pupils had a positive (COVID-19) test, compared with 21.5% of primary pupils and 33.2% of secondary-age pupils in the least deprived areas.
By 31 March 2022, 26% of secondary school pupils had two or more positive tests compared with only 4% of primary pupils.
'Pupils testing positive for coronavirus (COVID-19) in the spring 2022 term were less likely than those in the autumn 2021 term to report having COVID-19 symptoms at the time of the positive test; 29.5% of secondary school aged pupils and 34.5% of primary school aged pupils testing positive compared with 50.3% and 52.1%, respectively, in the autumn 20221 term.
The coronavirus (COVID-19) case data presented in this release are produced using the linked English Schools Census (ESC) and NHS Test and Trace datasets. This dataset covers pupils in state-funded schools only (including special schools).
Using Test and Trace data to monitor coronavirus (COVID-19) infection relies on infections being diagnosed and recorded. Testing behaviour and changes to testing guidance will affect trends seen in the data over time. These figures cannot be used to estimate the true proportion of pupils that have had a COVID-19 infection and may not be representative of true infection patterns between different demographics.
This article focuses on the two most recent academic terms: autumn 2021 (31/08/2021 to 22/12/2021, Delta dominant) and spring 2022 (03/01/2022 to 06/04/2022, Omicron dominant) to understand how the proportions of pupils testing positive and their characteristics changed over time.
Changes to the testing guidance in the second half of the spring 2022 term mean it is likely that a lower proportion of infections was recorded in the Test and Trace data (see link to measuring the data).
Data by term for the previous academic year are also available in our accompanying dataset.Back to table of contents
8. Number of reported positives
At the end of the Delta-dominant period (20 Dec 2021) 48% of secondary school-aged pupils had at least one coronavirus (COVID-19) infection and 12% had two or more. By 31 March 2022 69% of secondary school-aged pupils had at least one (COVID-19) infection(s), with 26% having two or more and 5% three or more.
By 31 March 2022, 36% of primary school-aged pupils had at least one (COVID-19) infection(s), with only 4% of primary pupils having two or more infections.
The proportion of secondary school-aged pupils having had multiple (COVID-19) infection(s) (26%) is higher than that seen in school staff where only 2.5% had two or more infections by 31 March 2022.
More information on how a new infection has been classified can be found in Section 10: Glossary. These data likely underestimate the number of infections because of asymptomatic or mild infections being missed and less widespread testing in earlier (original or alpha-dominant) periods. In particular, the proportion of primary school pupils with at least one positive COVID-19 test is lower than the antibody levels found in the School Infection Survey. Lower levels of testing in primary pupils may partly account for this.
Figure 7: Over one in four secondary school pupils have had two or more infections
Number of infections per pupil in state-funded secondary schools, England, up to 31 March 2022
Source: Office for National Statistics, Linked School Workforce Census (Department for Education) and Test and Trace dataset (NHS)
- Test and Trace data cannot be used to estimate the true proportion of pupils that have had a COVID-19 infection.
Download this chart Figure 7: Over one in four secondary school pupils have had two or more infectionsImage .csv .xls
9. Testing rate
The 'testing rate' was found to vary by important demographics and, on average, groups who were less likely to have a positive coronavirus (COVID-19) test were also less likely to have a previous record of a negative COVID-19 test result on the system.
The 'testing rate' was calculated by taking the number of negative tests recorded in the Test and Trace data over the autumn and spring term for each pupil (stopping when the first positive test was recorded in the time period) and then dividing this by the number of days "at risk", meaning the number of days up until the first positive or the end of the period if no positive was recorded.
This analysis will underestimate true testing behaviour, negative polymerase chain reaction (PCR) tests will be automatically recorded by the testing labs but it is likely that a large number of negative Lateral Flow Device (LFD) test results were not reported on the system (see measuring the data for guidance on LFD testing in school pupils). However, the results obtained show a clear pattern and suggest that differences in testing behaviour likely explain some of the trends in positive cases reported in this article.
For example, primary school pupils had an average of 1.2 negative tests per 1,000 days at risk compared with 4.3 per 1,000 days for secondary pupils. When looking at Income Deprivation Affecting Children Index (IDACI) decile, secondary pupils in the least deprived decile had a testing rate of 6.8 per 1,000 days compared with 2.5 per 1,000 days for those in the most deprived decile.Back to table of contents
Age and year groups
Ages referred to in this publication are the age of the child or pupil on 31 August at the start of the relevant academic year (31 August 2021 for 2021/22). Therefore, all reception children are recorded as being aged 4 years, those in year 7 as being aged 11 years and those in year 11 as being aged 15 years. Therefore, a pupil's recorded age may not be their actual age at the time of their reported positive test.
The outcome measure includes positive polymerase chain reaction (PCR) test results recorded by the testing labs or lateral flow device (LFD) test results reported by individuals on the Test and Trace system. Several positive tests can be recorded for each individual. Up until 20 December 2021, we consider positives more than 120 days after the first positive of that infection episode to be new infections, to be consistent with our existing publications on COVID-19. From 20 December 2021 onwards, positives more than 90 days after the first positive of that infection episode are considered a new infection.
Income Deprivation Affecting Children Index (IDACI)
The Income Deprivation Affecting Children Index (IDACI) is used to calculate deprivation deciles based on the proportion of children aged 0 to 15 years living in deprived income households (meaning households not working or working on low incomes eligible for means tested benefits) in 2019. The index ranks 32,844 LSOAs from the 2011 Census in England, from most deprived to least deprived, and divides them into 10 equal groups. For example, small area X is ranked 5,000 out of 32,844 small areas in England, where 1 is the most deprived. This means that small area X is among the 20% most deprived small areas in the country and therefore would be in IDACI decile 2. The Department for Communities and Local Government have published further information.
Special educational needs (SEN)
The Department for Education and Department for Health and Social Care defines a child as having special educational needs (SEN) if "they have a learning difficulty or disability which calls for special educational provision to be made for him or her. A child of compulsory school age or a young person has a learning difficulty or disability if he or she has a significantly greater difficulty in learning than the majority of others of the same age or has a disability which prevents or hinders him or her from making use of facilities of a kind generally provided for others of the same age in mainstream schools or mainstream post-16 institutions." In this article, we use information recorded about whether a pupil has SEN recorded by schools as part of the English Schools Census.
Variants of Coronavirus (COVID-19)
In the time periods analysed in this article, there have been different dominant variants of SARS-CoV-2, the virus causing coronavirus (COVID-19), at each point in time. In the autumn 2020 term, the original strain of COVID-19 was dominant, with Alpha emerging towards the end of the term becoming dominant on 21 December 2020. In the autumn 2021 term, Delta was the dominant variant. Omicron infections were identified towards the end of this term but were not considered dominant until 20 December 2021. Omicron was the dominant variant in the spring 2022 term.Back to table of contents
11. Data sources and quality
Measuring the data
Data from the English Schools Census (ESC), NHS Test and Trace, and the National Immunisation Management Dataset (NIMS) were linked to produce the analysis used in this article. For further information on the data linkage process and ESC data please see our previous publication.
Test and Trace records all Coronavirus (COVID-19) testing that takes place in England. These figures are updated daily and retrospective updates can be made. The outcome measure includes individuals receiving a positive polymerase chain reaction (PCR) or lateral flow device (LFD) test result recorded in the Test and Trace data.
Access to free lateral flow device (LFD) tests for everyone in England was introduced on 9 April 2021, with the aim of identifying and isolating asymptomatic cases to prevent onward transmission. At the beginning of the 2021 Autumn term, secondary pupils were advised to take two onsite LFD tests prior to their return to school and then continue testing twice weekly at home. Variation in the uptake and/or reporting of LFD testing could also have an impact on the trends reported here. From 11 January 2022, the need for a confirmatory PCR test following a positive LFD test result was dropped placing greater reliance on the individual to record the result on the Test and Trace system.
From 21 February onwards, the guidance to test twice a week for schools was dropped. From 24 February, close contacts were no longer required to test daily for seven days and from 31 March 2022, access to free COVID-19 testing ended for the majority of the population in England. These changes will further affect the identification of new infections in the second half of the spring 2002 term. The large increase in cases reported in the Coronavirus (COVID-19) Infection Survey from mid-March 2022 are not seen in the Test and Trace data Coronavirus (COVID-19) latest insights – Office for National Statistics (ons.gov.uk)
This is analysis of newly collected data, and our understanding of it and its quality will improve over time. The estimates presented in this release are experimental statistics as the NHS Test and Trace data is subject to further quality assurance tests.
One strength of the dataset is its size. The English Schools Census (ESC) contains pupil-level data collected from all state-funded schools in England. This represents over 8 million pupils aged 4 to 17 years and allows for potential analysis of smaller under-representative groups.
The data contain a rich source of background characteristics, which allow us to analyse how proportions of pupils reporting positive tests for coronavirus (COVID-19) differ by socio-demographic group and examine the extent to which these differences are driven by other factors.
Making use of existing administrative data sources avoids the need to set up bespoke surveys, which can be costly and suffer from response bias.
Using Test and Trace data to monitor trends in coronavirus (COVID-19) infection relies on infections being diagnosed, which is influenced by:
whether or not people have symptoms
a person's awareness of contact with an infected person
willingness to test
Changes to isolation rules over time may also influence the willingness to test and the impact of these rules and any changes could vary between different socio-demographic groups. This means the Test and Trace data cannot be used to provide an estimate of the true positivity rates within the population.
We are not able to confirm whether positive tests that we have classified as reinfections are actual new infections or a continuation of a previous infection as this would require genetic sequencing. Conversely, by only counting positive tests occurring 90 days after the first positive in the previous infection episode, we may be missing genuine new infections that occurred in a shorter space of time.
The latest available English Schools Census (ESC) data relate to the previous academic year, pupils have been rolled forward by one academic year in the analysis. Pupils of compulsory school age who have left England or the state school sector will still be included and those who joined after 21 January 2021 will not be included.Back to table of contents
12. Future developments
We will continue to examine the analytical potential of the linked data asset and expand on our existing analysis.Back to table of contents
This analysis was produced by the Office for National Statistics (ONS) with support from our School Infection Survey research partners at the London School of Hygiene and Tropical Medicine and UK Health Security Agency.Back to table of contents
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