COVID-19 test and tracing within schools: FOI release

Information request and response under the Freedom of Information (Scotland) Act 2002

Information requested

1. Since the end of March 2020, can you tell me how many positive tests for COVID-19 have been traced to transmission within school settings and if there have been any, how many of these have been from child to adult, adult to child or adult to adult

2. What is the known False Positive Rate for the PCR testing equipment?

3. For PCR tests, what is the threshold number of test cycles within which a positive test can be detected?

4. Is the cycle number where the positive result was detected provided by the test lab as part of the test result. Is so can you provide details of the cycle numbers at which all positive tests were identified since March 2020 

5. Is there a threshold number of testing cycles at which a positive case is deemed to be no longer infectious. If so who decides this threshold and is it the same for Pillar 1 and Pillar 2 tests. How, and by whom, has such a threshold value been agreed.

6. Broken down by day, how many positive tests have been registered for individuals who were asymptomatic when tested and how many for individuals who had symptoms.

7. What result is recorded if a person books a test and doesn't show?

8. Can you provide the total number of tests and the number of positive test results recorded in NHS Scotland labs since June 2020 by day.


1. While our aim is to provide information whenever possible, under section 17 of FOISA and in this instance the Scottish Government does not have the information you have requested.
However, you may wish to contact Public Health Scotland, who may be able to help you. Please see the following links –

2. No laboratory test is 100% accurate. We know that the prevalence of infection can impact the positive predictive value of a test, meaning that low levels of infection may lead to false positive results in a small number of cases. Public Health Scotland have produced guidance for sampling and laboratory investigations which includes protocols for reporting SARS COV-2 PCR positives during periods of low transmission prevalence:

I would also refer you to the frequently asked questions document referenced above.

3. Rate of cycles at which a PCR test is run depends on the platform – there is no uniform rate

For questions 4, 5 & 7
The Scottish Government does not have the information you have requested. However, you may wish to contact, NHS National Services Scotland who may be able to help you. Please see the following link –

6. The Scottish Government does not hold this information – This is a formal notice under section 17 of FOISA, Information not held. However, you may wish to contact Public Health Scotland who may be able to help.

8. Please see the following link where you can find the total number of tests and the number of positive test results recorded in NHS Scotland labs which cover 28th February 2020 to date.!/vizhome/COVID-19DailyDashboard_15960160643010/Overview

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Please quote the FOI reference
Central Enquiry Unit
Phone: 0300 244 4000

The Scottish Government
St Andrews House
Regent Road

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