COVID-19 cases are identified by taking specimens from people and testing them for the SARS-CoV-2 virus. If the test is positive, this is a case. Cases identified using two types of test for the SARS-CoV-2 virus are reported on the dashboard: • Polymerase chain reaction (PCR) tests, which require processing in a laboratory • Rapid lateral flow virus (LFD) tests, which are swab tests that give results in less than an hour, without needing to go to a laboratory. All lateral flow tests reported via the “Report a COVID-19 rapid lateral flow test result” GOV.uk service are included. The service cannot be used to report results from test kits that are paid for, and therefore results from paid for test kits are not included in figures on the dashboard. Some positive rapid lateral flow test results are confirmed with lab-based polymerase chain reaction (PCR) tests taken within 72 hours. If the PCR test results are negative, these are not reported as confirmed cases. People who test positive again after a given time period are counted as new cases. In England people are counted as new cases if they test positive again more than 90 days after their last positive test. Data for the last 7 days by specimen date are considered incomplete as it takes time to get test results and record them on relevant lab systems. Cases data for England includes all positive lab-confirmed PCR test results plus, positive rapid lateral flow tests unless followed by a negative PCR test taken within 72 hours. The count of reported new cases in the last 7 days is the total of the daily cases counts in the 7 days up to and including the most recent date with "complete" data (i.e. 7 days before the current date)
This figure will underestimate the actual number of COVID-19 infections due to people not testing or not being able to report LFD results. Variation in cases can reflect differences in the underlying population, including variation in vaccination status, public health measures and community transmission.