Influenza percentage of positive PCR tests in last 7 days
Last updated on Monday, 1 July 2024 at 10:26am
Summary
- Topic
- Influenza
- Category
- headline
- API name
influenza_headline_positivityLatest
Rationale
Seasonal influenza occurs every year and is a key driver for winter pressure on the NHS. The impact of influenza on the NHS depends on several factors:
- which strains of the virus are circulating and who is most likely to be affected
- how effective the annual vaccine is
- how many people are immunised
- winter temperatures.
Testing is required to identify cases of influenza.
Definition
This metric shows the percentage of the total number of polymerase chain reaction (PCR) tests for influenza taken in the last 7 days which had a positive result.
Data is shown by the date that the test was taken (specimen date).
Methodology
Testing for influenza is performed using PCR tests, which require processing in a laboratory.
Updates from SARI Watch are published in the UKHSA National Influenza and COVID-19 Surveillance Report on a Friday (weekly during influenza season and fortnightly in the summer months) and contains data up to the previous Sunday.
Positivity is calculated as the count of number of PCR tests taken in the last 7 days up to and including the most recent date which had a positive result, divided by the total number of positive or negative PCR tests taken in the last 7 days up to and including the most recent date.