Europe 26 Sep 2026 · Dr Natalya Mathur
ENCLAI ID ENCLAI-2026-0000443-1 · Cite

35% fewer flu cases in the UK: 899 in the last 30 days

ENCLAI SURVEILLANCE BRIEFING · 26 SEPTEMBER 202635% fewer flu cases in the UK: 899 inthe last 30 daysSeasonal influenza · The UK · reported cases899reported cases in the 30 days to 26 September▼ 35% fewer than the 30 days before (1,385)1,385The 30 daysbefore2,44290 days to 26September2,4422026 so far22 of 39rank, reportingcountriesThree 30-day windows1,38530 days before899Last 30 daysLargest counts, last 90 daysAustralia29,378Spain2,735The UK2,442Mexico2,064Norway2,009Germany1,52731 countries with a reported count in this windowWhat this briefing shows1Reported cases fell from 1,385 to 899 between the two latest 30-daywindows, 35% fewer.2The UK accounts for 0.1% of the flu cases reported to ENCLAIworldwide in 2026 and ranks 22 of 39 reporting countries.Read with care: reports to official surveillance, not people and not a rate. A change between30-day windows can come from reporting timing as much as from transmission.Source: official surveillance reports compiled by ENCLAI · data as of 2026-09-26 ·enclai.net/newsVerify every figure against the source data before use; ENCLAI does not guarantee accuracy orcompleteness.
  1. Reported cases fell from 1,385 to 899 between the two latest 30-day windows, 35% fewer.
  2. The UK accounts for 0.1% of the flu cases reported to ENCLAI worldwide in 2026 and ranks 22 of 39 reporting countries.
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Largest included reported counts (6 of 31 countries) · 2026-06-28 through 2026-09-26 · source-record dates; coverage varies
Australia29,378
Spain2,735
United Kingdom2,442
Mexico2,064
Norway2,009
Germany1,527
Seasonal influenza — United Kingdom · reported surveillance count · 2026-06-28 through 2026-09-26 · inclusive source-record dates
Seasonal influenza — United Kingdom · reported surveillance count · 2026-08-27 through 2026-09-26 · inclusive source-record dates
Seasonal influenza — United Kingdom · reported surveillance count · 2026-07-27 through 2026-08-26 · inclusive source-record dates
Seasonal influenza — United Kingdom · reported surveillance count · 2025-08-27 through 2025-09-26 · inclusive source-record dates
Seasonal influenza · combined reported surveillance count · 2026-06-28 through 2026-09-26 · inclusive source-record dates
Seasonal influenza · weekly reported-count series · Weeks starting 2026-06-22 through 2026-09-07
Largest included reported counts (6 of 31 countries) · 2026-06-28 through 2026-09-26 · source-record dates; coverage varies

The full briefing

Full 2026 picture: Seasonal influenza in United Kingdom — reported cases by year, monthly records and every briefing for this pair.

The UK reported 2,442 flu cases in the 90 days to 26 September. 899 of them came in the 30 days to 26 September, against 1,385 in the 30 days before.

Why it matters

The UK accounts for 0.1% of the flu cases reported to ENCLAI worldwide so far in 2026. It ranks 22 of 39 reporting countries.

The numbers

PeriodReported cases
Last 30 days (to 26 September)899
The 30 days before that1,385
90 days to 26 September2,442
2026 so far (ENCLAI export)2,442
The card shows flu in the UK. It compares the last 30 days with the 30 days before, as reported to ENCLAI.
The card shows flu in the UK. It compares the last 30 days with the 30 days before, as reported to ENCLAI.

What the source says

These figures come from official surveillance reports. They count reports, not people. They are not an incidence rate, the rate of new cases in a population. They do not cover the whole population. The reporting periods do not match these dates exactly. Some reports are incomplete or still in progress. Some run past the window. Some reports do not say which date they use: symptom onset, notification, or confirmation.

Caveats

  • A change between two 30-day windows can come from reporting timing as much as from transmission. The source does not say which.

Where to learn more

Seasonal influenza in the UK: the 2026 picture · Seasonal influenza worldwide · the UK: all diseases · How to read these counts

Retained reporting context

Included reporting countries

Seasonal influenza

44,698

combined reported surveillance count

2026-06-28 through 2026-09-26 · inclusive source-record dates

For Seasonal influenza, the combined reported surveillance count across the 31 countries with positive reported counts in this selection is 44,698. The selection uses source-record dates 2026-06-28 through 2026-09-26, inclusive. This covers only these reporting countries; source periods and completeness vary.

Exact included country membership
CountryReported countSource-record dates
Australia29,3782026-06-28 through 2026-09-26
Austria92026-06-28 through 2026-09-26
Belgium1422026-06-28 through 2026-09-26
Bulgaria142026-06-28 through 2026-09-26
Canada7322026-06-28 through 2026-09-26
Switzerland2562026-06-28 through 2026-09-26
Czechia102026-06-28 through 2026-09-26
Germany1,5272026-06-28 through 2026-09-26
Denmark2662026-06-28 through 2026-09-26
Spain2,7352026-06-28 through 2026-09-26
Estonia332026-06-28 through 2026-09-26
Finland1592026-06-28 through 2026-09-26
France3272026-06-28 through 2026-09-26
United Kingdom2,4422026-06-28 through 2026-09-26
Croatia282026-06-28 through 2026-09-26
Hungary22026-06-28 through 2026-09-26
Ireland7902026-06-28 through 2026-09-26
Iceland332026-06-28 through 2026-09-26
Luxembourg1092026-06-28 through 2026-09-26
Mexico2,0642026-06-28 through 2026-09-26
Malta6472026-06-28 through 2026-09-26
Netherlands2162026-06-28 through 2026-09-26
Norway2,0092026-06-28 through 2026-09-26
Nepal222026-06-28 through 2026-09-26
Portugal1932026-06-28 through 2026-09-26
Romania22026-06-28 through 2026-09-26
Slovakia312026-06-28 through 2026-09-26
Slovenia142026-06-28 through 2026-09-26
Sweden2152026-06-28 through 2026-09-26
Taiwan132026-06-28 through 2026-09-26
United States2802026-06-28 through 2026-09-26

Snapshot 2026-09-26

Weekly reporting history

Seasonal influenza

weekly reported-count series

Weeks starting 2026-06-22 through 2026-09-07

A retained retrospective weekly reported-count series across included reporting countries. Country membership and reporting completeness can vary by week. Missing weeks remain gaps. This is a separate report-series measure; it does not establish exact incidence or laboratory confirmation.

Retained weekly report series
WeekReported count
2026-06-22 through 2026-06-2816151
2026-06-29 through 2026-07-0514120
2026-07-06 through 2026-07-1212645
2026-07-13 through 2026-07-1916894
2026-07-20 through 2026-07-2612989
2026-07-27 through 2026-08-0217639
2026-08-03 through 2026-08-0910940
2026-08-10 through 2026-08-1621677
2026-08-17 through 2026-08-2317993
2026-08-24 through 2026-08-3024132
2026-08-31 through 2026-09-0638372
2026-09-07 through 2026-09-1337182

Snapshot 2026-09-25

Sources and limitations

  • Window. Each quantity keeps its recorded source-selection dates and coverage notes. Dated batches and weekly or genomic observations retain their separate measures. Publication or capture dates do not establish case onset, equal cohorts or period completeness.
  • Denominator. The retained counts do not establish complete populations, equal reporting cohorts or incidence rates. Source period bounds and definitions can differ.
  • Case definition. Case definitions are set nationally and change over time. Counts for the same disease in different countries may not be counting the same thing.
  • Revisions. Agencies restate figures. Values here are as reported at the time of publication; see the update history below.

ENCLAI counts reflect verified records available from reporting sources for the stated window. They are not estimates of total incidence and should not be interpreted as medical advice. Full methodology: the dataset.

Review and corrections

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