Work is underway in NHS Test and Trace to digitally label samples associated with surge testing, through an end-to-end process from sample to sequence. In the interim, this preliminary analysis uses a pragmatic proxy of samples identified through local surge testing initiatives as:
Tests undertaken as part of surge testing but from persons resident in other postcodes or processed through a test site not designated as surge testing using the definition above, will not be included in this proxy.
Indicators are presented by ‘locality’ of area targeted for surge testing and the test sites linked to it (including MTU deployment). Locality names are the operational names assigned by Test and Trace and do not necessarily relate to strict geographical boundaries. Specimens from individuals who do not reside in the locality – but who have been tested at a site associated with the locality for surge testing – may be included.
All variant of concern or variant under investigation samples identified through surge testing are verified through established PHE dataflows and matched to the earliest positive specimen of a case in the daily line list of cases. Therefore, this report does not include sequencing for any cases with a positive specimen taken prior to surge testing. Data from the last 7 days has been excluded to allow time for sequencing data to be reported.
Lateral Flow Device (LFD) testing and cases first identified using LFD are included. Cases first identified using LFD may have a later PCR sample which has been sequenced. LFD contribution to case rate is assumed to be similar in surge and non-surge areas and therefore should not impact comparative sequencing estimates.