2.1 Episodes of influenza, RSV and COVID-19

The number of new influenza episodes increased in week 36, with 25 unique episodes identified. There were 14 episodes reported in week 35. There were no new RSV episodes identified in week 36, which is a decrease from week 35 when one episode was identified (Figure 2.1).

Influenza and RSV episode rates by age groups are shown in (Figure 2.2). The highest influenza episode rate in week 36 was in the 75+ age group (4.6 per 100,000 population).

Influenza and RSV episode rates across local government districts (LGD) are shown in (Figure 2.3). Fermanagh and Omagh had the highest influenza episode rate in week 36 (4.3 per 100,000 population).

The number of new COVID-19 episodes increased in week 36, with 117 unique episodes identified compared with 101 in week 35 (Figure 2.1).

COVID-19 episode rates by age groups are shown in (Figure 2.2). The highest COVID-19 episode rate in week 36 was in the 75+ age group (28.4 per 100,000 population).

COVID-19 episode rates across LGD are shown in (Figure 2.3). Mid and East Antrim had the highest COVID-19 episode rate in week 36 (9.3 per 100,000 population).

Supplementary tables of unique episodes and weekly episode rates are shown at the end of this report.

Figure 2.1: Weekly number of unique episodes of influenza, RSV and COVID-19 by epidemiological week

Figure 2.2: Weekly episode rates of influenza, RSV and COVID-19 per 100,000 population, by age group, by epidemiological week

Figure 2.3: Weekly episode rates of influenza, RSV and COVID-19 per 100,000 population, by local government district, by epidemiological week

2.2 Testing and positivity (%)

In week 36 there were 1,421 influenza tests, 25 of which were positive (1.8% positivity). This is higher to week 35 (1.1% positivity) (Figure 2.4).

There were 783 RSV tests, of which none were positive (0.0% positivity). This is similar to week 35 (0.2% positivity) (Figure 2.4).

There were 1,182 COVID-19 tests, 125 of which were positive (10.6% positivity). This is higher to week 35 (8.9% positivity) (Figure 2.4).

There were 230 rhinovirus tests, 33 of which were positive (14.4% positivity). This is higher to week 35 (6.8% positivity) (Figure 2.4).

A supplementary table of testing and positivity is shown at the end of this report.

Figure 2.4: Weekly positivity for influenza, RSV and COVID-19, by year and epidemiological week

Shading represents 95% confidence intervals.

In week 36 there were 230 adenovirus tests, two of which were positive (0.9% positivity). This is lower to week 35 (1.4% positivity) (Figure 2.5).

There were 230 parainfluenza tests, four of which were positive (1.7% positivity). This is similar to week 35 (1.8% positivity) (Figure 2.5).

There were 230 human metapneumovirus (hMPV) tests, of which none were positive (0.0% positivity). This is similar to week 35 (0.0% positivity) (Figure 2.5).

Figure 2.5: Weekly positivity for adenovirus, parainfluenza and Human metapneumovirus, by year and epidemiological week

Shading represents 95% confidence intervals.

2.3 Influenza sub-typing

Of the 25 new influenza episodes identified in week 36, two were typed as Flu A (H1), one was Flu A (H3), 21 were Flu A (not subtyped) and one was Flu B (Figure 2.6).

A supplementary table of influenza sub-typing is shown at the end of this report.

Figure 2.6: Weekly number of unique episodes of influenza, by subtype and epidemiological week

2.4 Sentinel surveillance

Sentinel surveillance plays a role in monitoring and understanding the spread and impact of respiratory viruses like influenza and COVID-19 in the community. It involves a systematic and targeted approach to collect data from a geographical representative subset of GP practices (~18% population representative) to provide information about virus activity across NI.

In week 36, three samples were positive for influenza from 10 samples submitted for testing (30.0% positivity) to the Regional Virus Laboratory (RVL). One was typed as Flu A (H1) and two were Flu A (not subtyped). No samples were positive for RSV from 10 samples submitted for testing (0.0% positivity). One sample was positive for COVID-19 from nine samples submitted for testing (11.1% positivity) (Table 1).

Total sentinel cases of influenza, RSV and COVID-19 by age group for the previous year are shown in (Figure 2.7), (Figure 2.8) and (Figure 2.9), and cumulatively for the 2024/25 influenza season in Table 2.

A supplementary table of testing and positivity is shown at the end of this report.

Figure 2.7: Weekly sentinel influenza cases, by age group, by epidemiological week

Figure 2.8: Weekly sentinel RSV cases, by age group, by epidemiological week

Figure 2.9: Weekly sentinel COVID-19 cases, by age group, by epidemiological week

2.5 Non-sentinel surveillance

Non-sentinel surveillance is the monitoring of respiratory viruses from virology data collected from settings such as hospitals and GPs (excluding the sentinel GPs). This provides information about virus activity across NI.

In week 36, 22 samples were positive for influenza from 1,411 samples submitted for testing to laboratories across NI (1.6% positivity). One was typed as Flu A (H1), one was Flu A (H3), 19 were Flu A (not subtyped) and one was Flu B. No samples were positive for RSV from 773 samples submitted for testing (0.0% positivity). 124 samples were positive for COVID-19 from 1,173 samples submitted for testing (10.6% positivity) (Table 3).

Total non-sentinel cases of influenza, RSV and COVID-19 by age group for the previous year are shown in (Figure 2.7), (Figure 2.8) and (Figure 2.12), and cumulatively for the 2024/25 influenza season in Table 4.

A supplementary table of testing and positivity is shown at the end of this report.

Figure 2.10: Weekly non-sentinel influenza cases, by age group, by epidemiological week

Figure 2.11: Weekly non-sentinel RSV cases, by age group, by epidemiological week

Figure 2.12: Weekly non-sentinel COVID-19 cases, by age group, by epidemiological week

2.6 SARS-CoV-2 variants

In the 8 weeks 30 June 2025 to 24 August 2025, 179 COVID-19 samples were sequenced. Of these, 44 were XFG (24.6% of all sequenced samples), 35 were XFG.3 (19.6% of all sequenced samples), 17 were NB.1.8.1 (9.5% of all sequenced samples), 8 were KP (4.5% of all sequenced samples), 7 were LP.8.1 (3.9% of all sequenced samples), 6 were JN.1 (3.4% of all sequenced samples), 5 were XEC (2.8% of all sequenced samples), and 3 were BA.2 and BA.3 (both 1.7% of all sequenced samples). Due to small numbers of samples sequenced, the level of confidence in precision of the estimate is low, and the percentages of each variant may change as further results become available. A more detailed COVID-19 Genomics Bulletin containing a further breakdown of sub-lineages is published weekly.

Parent lineages displayed are subject to change based on lineages under monitoring by the UKHSA horizon scanning team.

Figure 2.13: Total number of sequenced variants of COVID-19 by Pangolin lineage, by epidemiological week

Recombinant refers to any recombinant lineage, starting “X”, that does not fall under the parent lineage of a defined variant.

3.1 Consultation rates for influenza/influenza-like-illness (‘flu/ILI’)

The general practice (GP) flu/ILI consultation rate during week 36 was 1.9 per 100,000 population. This is similar to week 35 (1.7 per 100,000 population). Rates are at baseline activity levels (<10.1 per 100,000 population) (Figure 3.1).

The highest rate in week 36 was seen in the 45-64 age group (2.6 per 100,000 population) (Figure 3.2).

The highest rate in week 36 was seen in the South Eastern Trust (2.8 per 100,000 population) (Figure 3.3).

Supplementary tables of GP consultation rates are shown at the end of this report.

Figure 3.1: Northern Ireland GP consultation rates for ‘flu/ILI’, 2021/22 – 2024/25

Figure 3.2: GP consultation rates for ‘flu/ILI’, by age group, 2021/22 – 2024/25

Figure 3.3: GP consultation rates for ‘flu/ILI’, by HSCT, 2021/22 – 2024/25

3.2 Consultation rates for acute respiratory infection (ARI)

The GP ARI consultation rate during week 36 was 111.1 per 100,000 population. This is higher to week 35 (85.6 per 100,000 population) (Figure 3.4).

The highest rate in week 36 was seen in the 0-4 age group (255.2 per 100,000 population) (Figure 3.5).

The highest rate in week 36 was seen in the Western Trust (134.4 per 100,000 population) (Figure 3.6).

Supplementary tables of GP consultation rates are shown at the end of this report.

Figure 3.4: Northern Ireland GP consultation rates for ARI, 2021/22 – 2024/25

Figure 3.5: GP consultation rates for ARI, by age group, 2021/22 – 2024/25

Figure 3.6: GP consultation rates for ARI, by HSCT, 2021/22 – 2024/25

3.3 Consultation rates for COVID-19

The GP COVID-19 consultation rate during week 36 was 2.9 per 100,000 population. This is slightly higher to week 35 (2.2 per 100,000 population) (Figure 3.7).

The highest rate in week 36 was seen in the 75+ age group (9.4 per 100,000 population) (Figure 3.8).

The highest rate in week 36 was seen in the South Eastern Trust (4.1 per 100,000 population) (Figure 3.9).

Supplementary tables of GP consultation rates are shown at the end of this report.

Figure 3.7: Northern Ireland GP consultation rates for COVID-19, 2021/22 – 2024/25

Figure 3.8: GP consultation rates for COVID-19, by age group, 2021/22 – 2024/25

Figure 3.9: GP consultation rates for COVID-19, by HSCT, 2021/22 – 2024/25

4.1 Influenza, RSV and COVID-19 care homes outbreaks

There was one COVID-19 outbreak reported in a care home setting in week 36. This is similar to week 35 (one COVID-19 outbreak reported) (Figure 4.1).

Figure 4.1: Weekly number of confirmed influenza, RSV and COVID-19 outbreaks, by year and epidemiological week

5.1 Admissions and occupancy

There were 58 new community-acquired emergency hospital admissions during week 36 (Figure 5.1). This is higher compared to week 35 (50 admissions). Of the 58 new admissions, six were Flu A and 52 were COVID-19. The 75+ age group had the majority of community acquired emergency influenza hospital admissions in week 36 (33.3%). The 75+ age group had the majority of COVID-19 hospital admissions (48.1%).

A supplementary table of community-acquired emergency hospital admissions is shown at the end of this report.

Community acquired emergency influenza and RSV inpatients have remained stable while COVID-19 inpatients has increased (Figure 5.2).

Figure 5.1: Weekly number of community-acquired emergency influenza, RSV and COVID-19 hospital admissions, by year and epidemiological week

Figure 5.2: Influenza, RSV and COVID-19 community acquired emergency inpatients, by day

6.1 Deaths related to influenza and/or pneumonia

NISRA death statistics are published weekly. From week ending 31 January 2025 these statistics now include a count of deaths related to influenza and/or pneumonia.

The statistics report on deaths where influenza and/or pneumonia was mentioned anywhere on the death certificate. As a result, the counts will reflect deaths where influenza or pneumonia has contributed to a death but was not necessarily the underlying cause of the death.

The latest data is available from week ending 29 August 2025. In week 35, 51 influenza and/or pneumonia related deaths out of 287 deaths were reported (17.8%). This is higher to the previous week with 53 influenza and/or pneumonia related deaths out of 332 deaths reported (16.0%) (Figure 6.1).

Figure 6.1: Weekly deaths and percentage of registered deaths related to influenza and/or pneumonia, to most recent registration week

6.2 Deaths related to COVID-19

NISRA death statistics report on deaths where COVID-19 was mentioned anywhere on the death certificate. As a result, the counts will reflect deaths where COVID-19 has contributed to a death but was not necessarily the underlying cause of the death.

The latest data is available from the week ending 29 August 2025. In week 35, four COVID-19 related deaths out of 287 deaths were reported (1.4%). This is similar to the previous week with four COVID-19 related deaths out of 332 deaths reported (1.2%) (Figure 6.2).

Figure 6.2: Weekly deaths and percentage of registered deaths related to COVID-19, to most recent registration week

6.3 Excess Mortality

NISRA use the UK-wide methodology to report on excess deaths as advised by the Office for National Statistics (ONS).

EuroMOMO is a European mortality monitoring activity, aiming to detect and measure excess deaths related to seasonal influenza, pandemics and other public health threats. Reports on excess deaths across Europe and the United Kingdom are published weekly.

8.1 Presentation of data

Unless otherwise stated, data are presented using epidemiological weeks (a standardised method of counting weeks [Monday-Sunday] to allow for the comparison of data year after year). This is dependent on the data available. The data included in this report are the most up to date data available at the time of the report; however, this is subject to change as the data are subject to ongoing quality assurance.

8.2 Virology surveillance

All virology data provided here are preliminary. Virology data for prior weeks, as included in this or future reports, are subject to updates based on laboratory returns received after the last report was produced. The current report offers the most current information available.

Rates per 100,000 population are calculated using the NISRA 2021 Mid-Year Population Estimates.

8.3 SARS-CoV-2 genomics

A subset of SARS-CoV-2 positive PCR samples are sent to sequencing laboratories in Belfast Health and Social Care Trust and Queen’s University Belfast for sequencing. On 29th November the lineage assignment algorithm was switched from PangoLEARN to UShER for lineage counts. PangoLEARN uses a machine learning algorithm, whereas UShER uses phylogenetic placement and produces fewer unassigned lineages. This switch has been applied retrospectively, therefore total counts for all lineages have been affected. A more detailed COVID-19 Genomics Bulletin containing a further breakdown of sub-lineages is published weekly.

8.4 Primary care surveillance

Consultation rates for influenza/influenza-like-illness (‘flu/ILI’), acute respiratory infection (ARI) and COVID-19

GP in-hours consultation data with ~95% coverage of the NI population is auto-extracted weekly from the General Practitioner Intelligence Platform (GPIP). This data includes weekly aggregate consultations for ‘flu/ILI’, ARI, and COVID-19, and includes weekly registered patients. The data is available for different Health and Social Care Trusts, and by age and sex.

8.5 Community surveillance

Care home outbreaks

PHA conducts surveillance of outbreaks across multiple settings, including care homes (nursing homes and residential homes) in NI that are registered with the Regulation and Quality Improvement Agency (RQIA). All care homes have a requirement to notify the PHA Health Protection duty room of suspected outbreaks of any infectious disease. A confirmed outbreak of influenza, RSV or COVID-19 can be defined as where there are two or more confirmed cases with onset within a 14 day period, where transmission within the Care Home facility is considered the likely cause.

8.6 Secondary care surveillance

Admissions and occupancy

It is not currently possible for this report to distinguish emergency from other types of admission for each Trusts hospital data following the introduction of a new electronic healthcare record (EPIC). This was introduced in the SEHSCT on 06/11/2023; BHSCT on 06/06/2024, NHSCT on 07/11/2024, and WHSCT and SHSCT on 28/04/2025. For this report, all community-acquired admissions are included from the respective dates above for each Trust, which will include non-emergency admissions (which are a small minority of the total admissions reported). Only admissions where the method of admission was ‘Emergency’ are counted before these dates for each Trust. Work is ongoing to adapt systems to new data sources and re-instate differentiation of emergency admissions. Ongoing developmental and quality assurance work may result in adjustments to figures.

Influenza and RSV

Community-acquired influenza and RSV emergency admissions to acute hospitals are estimated by combining data from the Patient Administration System (PAS), EPIC and virological reports in the Northern Ireland Health Analytics Platform (NIHAP). Admissions are counted where there was a positive test up to seven days before admission or up to one day after admission, and the method of admission was ‘Emergency’. The number of inpatients is counted at midnight. Admissions and occupancy refer to the first admission per infection episode.

COVID-19

Community-acquired COVID-19 emergency admissions are estimated by combining data from from PAS, EPIC and virological reports in NIHAP. Admissions are counted where there was a positive PCR or lateral flow test up to 14 days before admission or up to one day after admission. The number of inpatients is counted at midnight. Admissions and occupancy refer to the first admission per infection episode, including transfers between hospitals. The method used in this report is different to that previously reported by the Department of Health’s COVID-19 dashboard, which used administrative coding to identify COVID-19 admissions.

8.7 Mortality surveillance

NISRA death statistics are published weekly, and include weekly counts of deaths related to influenza and/or pneumonia (new from 31 January 2025), and deaths related to COVID-19. This enables comparisons with weekly information published by the Office for National Statistics (ONS) covering England and Wales.

The statistics report on deaths where influenza and/or pneumonia, or COVID-19, was mentioned anywhere on the death certificate. As a result, the counts will reflect deaths where these diseases have contributed to a death but was not necessarily the underlying cause of the death.

9.1 Unique episodes of influenza, RSV and COVID-19, by epidemiological week, over a six week period

9.2 Influenza, RSV and COVID-19 episode rates per 100,000 population, by age group, over a six week period

9.3 Influenza, RSV and COVID-19 episode rates per 100,000 population, by local government district, over a six week period

9.4 Total tests and positivity for influenza, RSV and COVID-19, by epidemiological week, over a six week period

9.5 Unique episodes of influenza, by subtype, over a six week period

9.6 Total sentinel tests and positivity for influenza, RSV and COVID-19, by epidemiological week, over a six week period

9.7 Total non-sentinel tests and positivity for influenza, RSV and COVID-19, by epidemiological week, over a six week period

9.8 Number of sequenced samples for variants in Northern Ireland

This table only shows counts for lineages with 10 or more sequenced samples from 2024 - 36 onwards. Lineage counts include provisional and confirmed sequencing samples. Lineage calls are subject to change following analysis of genomic sequence results, which may result in fluctuations in lineage counts.

9.9 Flu/ILI consultation rates per 100,000 population, by age group, over a six week period

9.10 Flu/ILI consultation rates per 100,000 population, by Health and Social Care Trust, over a six week period

9.11 ARI consultation rates per 100,000 population, by age group, over a six week period

9.12 ARI consultation rates per 100,000 population, by Health and Social Care Trust, over a six week period

9.13 COVID-19 consultation rates per 100,000 population, by age group, over a six week period

9.14 COVID-19 consultation rates per 100,000 population, by Health and Social Care Trust, over a six week period

9.15 Number of community-acquired emergency hospital admissions, over a six week period