Covid-19 Cases
Covid-19
Understanding the facts
cases
There are the latest statistics directly from the UK government
See common queries regarding these statistics answered below
COVID-19 cases are identified by taking specimens from people and testing them for the presence of the SARS-CoV-2 virus. If the test is positive, this is referred to as a case. Positive rapid lateral flow test results can be confirmed with Polymerase Chain Reaction (PCR) tests taken within 72 hours. If these PCR test results are negative, these are not reported as cases. People tested positive more than once are only counted once. The 7-day rolling mean average of daily cases is plotted on the chart on the middle day of each seven day period.
How do you test for Covid-19?
False positive results mean that an individual has tested positive but does not carry the virus.
What is a false positive?
Yes, as of 9 April 2021 the way cases are reported has changed. Cases that have been identified through a positive rapid lateral flow test are now removed for people who took PCR tests within 3 days that were all negative. Cases of this type that were previously reported have been removed from the cumulative total, reducing the total by 8,010. Newly reported numbers of cases for the UK and England were unaffected by the removal of these. Historical published date totals have not been changed.
Has the way cases are reported changed recently?
False negative results mean that an individual has tested negative but carries the virus.
What is a false negative?
Individuals who tested positive through a pillar 1 and pillar 2 test were counted twice in COVID-19 infection rates up to the 1st July 2020 as results from these tests were collected separately. On 2nd July 2020, 30,000 duplicates were found and removed from statistics causing a drop in overall cases.
From May 2021, in England, if an individual tested positive then negative within 3 days, the case would be removed from statistics. This usually occurs where a positive rapid lateral flow test is followed by a negative polymerase chain reaction test.
Why are confirmed cases sometimes removed from the case count?
The location of a case was initially assigned to the individuals main place of residence. November 2020 saw this change to than their address at the point of testing. As records are updated, these locations can change causing apparent discrepancies in case and case totals in local authorities. In England, where the regional location of the case is unknown, the case is excluded in regional counts.
How is the location of a case assessed?
In Scotland, Wales and Northern Ireland, no cases were reported on public holidays but rather were added to the report the following day inflating that day’s case total. Similarly, where technical issues in calculating case totals occur, the reported death total for that day may be added to the day after.
In Wales, from the 12 April 2021 Public Health Wales moved to a 6 day reporting period skipping Saturdays. Mondays reported cases over the 48 hour period from 9:00 Friday to 9:00 Sunday.
Why do some days experience inflations of case totals?
The case rate is calculated per 100,000 people. It is calculated by dividing the case count by the population and multiplying this by 100,000. As no adjustments are made for other factors these rates are rough estimates. It should also be noted that 2018 mid-year population estimates are used in these calculations as these are the most recent population statistics currently available. Assuming the population has increased, this may lead to inflated case rates.
How is the case rate calculated and how reliable is it?
The 7 day rolling average is calculated by adding the case total of the day in question with the case totals of the past 3 days and post 3 days then dividing this total by 7. This method smooths out sudden fluctuations in case rates across consecutive days.