Integrated Respiratory Virus Bulletin, Ireland

Week 1 2026 (starting from 04/01/2026)

Report prepared on 16/01/2026



This interactive bulletin reports on the latest epidemiology of COVID-19, influenza, respiratory syncytial virus (RSV) and other respiratory viruses (ORVs) in Ireland. HPSC monitors several integrated respiratory virus surveillance systems that are included in this bulletin. This report will be published weekly during the winter season (week 40 to week 20).

How to use this interactive bulletin

For interactive graphs – data values and labels can be seen by hovering over graph lines or bars. Specific categories can be selected or deselected by clicking on the relevant category in the legend. Readers can skip to specific sections by clicking on the table of contents to the left of the screen.

Please note: data based on notifications follow the epidemiological calendar, with the week beginning Sunday, while other surveillance systems follow the international ISO calendar where the week begins on Monday. Unless otherwise stated, data figures and tables in this report follow the epidemiological calendar. Because the 2025 epidemiological calendar includes a week 53 and the ISO calendar does not, week labels throughout 2026 will differ according to the calendar used.


1 Key messages

NOTE: Data for recent weeks should be interpreted with caution as surveillance data are impacted during the Christmas/New Year holiday period, due to changes in reporting, testing and associated changes with healthcare provision and healthcare seeking behaviour. Data for these weeks may not accurately reflect the epidemiological situation.


Influenza activity decreased across most surveillance indicators and was at moderate levels overall; activity is likely to have peaked in weeks 50–51, 2025. RSV activity decreased and was at moderate levels overall. COVID-19 activity decreased and was at low levels overall.

Vaccination/immunisation remains one of the most effective ways to reduce severe illness from influenza, RSV, and COVID-19. Strong surveillance, immunisation programmes, and healthcare system readiness (including Infection Prevention Control) are key to protecting public health.

1.1 Summary for most recent week

Syndromic surveillance

The sentinel GP Acute Respiratory Infection (ARI) consultation rate increased in ISO weeks 1 and 2 2026 but remained below the peak in week 50 2025. ARI rates remained at very high levels at 194.9/100,000 population during week 2. The highest rates were in those aged ≥ 65 years at 304.9/100,000 population. The sentinel GP influenza-like-illness (ILI) consultation rate decreased in recent weeks and was at moderate levels at 57.5/100,000 population during week 2. Sentinel GP influenza test positivity remained above baseline at 25% for week 2. RSV positivity increased and was above baseline at 14% for week 2. SARS-CoV-2 and all other seasonal respiratory pathogens’ test positivity levels were below the 10% threshold. The percentage of GP Out-Of-Hours (GP-OOH) calls for self-reported flu calls were stable and for self-reported cough calls decreased; both indicators were above the overall baseline for all ages during week 2.

COVID-19

COVID-19 activity decreased and was at low levels in week 1 2026. The overall incidence was 3.8/100,000 population. COVID-19 cases decreased by 10% in week 1 with 195 cases compared to 216 cases in week 53. Emergency Department (non-hospitalised) COVID-19 cases decreased by 19% from 122 in week 53 to 99 in week 1. Hospitalisations decreased by 6% from 66 cases in week 53 to 62 cases in week 1. There have been 20 ICU admissions and 65 deaths reported for this season to date. COVID-19 hospital bed occupancy has remained stable in recent weeks. XFG remained the predominant SARS-CoV-2 variant, accounting for 90% of samples sequenced between weeks 42 and 46 2025. A total of 11 Variant Under Monitoring (VUM) BA.3.2 sequences have been detected in confirmed cases to date in Ireland.

Influenza

Influenza activity decreased across most surveillance indicators in week 1 2026 and was at moderate levels overall and among <5 and 45–64 year olds. Influenza activity is likely to have peaked during weeks 50–51 2025. The overall incidence was 35.2/100,000 population and highest in ≥80 year olds. Influenza cases decreased by 12%, from 2047 cases in week 53 to 1811 cases in week 1. Emergency Department (non-hospitalised) influenza cases decreased by 28%, from 1291 in week 53 to 924 in week 1. Hospitalisations decreased by 15%, from 502 cases in week 53 to 429 cases in week 1. There have been 140 ICU admissions and 67 deaths reported for this season to date. Influenza hospital bed occupancy decreased in the most recent week. Influenza A(H3) accounted for the majority of subtyped influenza A viruses during the season to date. Of influenza A(H3N2) samples sequenced by the National Virus Reference Laboratory to date, the majority belonged to the new subclade K (Clade 2a.3a.1; former J.2.4.1). 

RSV

RSV activity was stable and remained at moderate levels overall, and at high levels in 15–44 year olds in week 1 2026. The overall incidence was 11.3/100,000 population and highest in <5 year olds. RSV cases decreased by 1%, from 588 cases in week 53 to 582 cases in week 1. Emergency Department (non-hospitalised) RSV cases increased by 6% from 260 in week 53 and 276 in week 1. Hospitalisations decreased by 28% from 210 cases in week 53 to 152 cases in week 1. There have been 46 ICU admissions and six deaths reported for the season to date. RSV hospital bed occupancy remained low and decreased last week.

Severe Acute Respiratory Infection (SARI)

In ISO week 2 2026, SARI activity decreased but remains at moderate levels in Ireland; 68 SARI cases were reported from two of four sentinel hospital sites. Influenza test positivity decreased from 30% in week 1 to 19% in week 2. In week 2 RSV test positivity decreased to 10% and SARS-CoV-2 test positivity increased to 5%.

Outbreaks

There were 68 acute respiratory infection (ARI) outbreaks notified in health and care settings during week 1 2026 (three COVID-19, 48 influenza, five RSV and 12 other ARI), an increase from the 59 ARI outbreaks reported during week 53. Of the 68 ARI outbreaks, 14 were in hospitals, 38 were in nursing homes, six were in residential institutions, six were in community hospital/long-stay units, three were in other healthcare services and one was in a non-healthcare setting. There was also one mixed COVID-19 and influenza outbreak notified during week 1.

Excess mortality

The latest HPSC excess mortality analysis of all registered deaths in Ireland up to January 11, 2026 (week 2 2026) using the standardised European EuroMOMO algorithm shows that there has been no excess mortality reported for the entire Irish population (all ages) during the 2025/2026 season (week 40 2025 onwards) and most recently in week 2 2026. However, excess pneumonia and influenza related mortality was observed most recently in week 52 2025 and week 1 2026.


2 Syndromic and case surveillance

2.1 Sentinel GP Acute Respiratory Infection (ARI) and Influenza-like-illness (ILI) surveillance

2.1.1 Sentinel GP ARI

1: Sentinel GP ARI and ILI consultation rates per 100,000 population overall (with associated number of influenza, RSV and SARS-CoV-2 positive sentinel GP ARI specimens) in Ireland, from week 40 2024 to week 2 2026. Data source: Sentinel GP surveillance system and National Virus Reference Laboratory (NVRL). Note: week number follows the ISO calendar


2.1.2 Sentinel GP ARI by age group

2: Sentinel GP ARI consultation incidence by age-group in Ireland, from week 40 2024 to week 2 2026. Data source: Sentinel GP surveillance system. Note: week number follows the ISO calendar


2.2 GP out-of-hours surveillance


3: Percentage of calls to GP out-of-hours services for self-reported cough and self-reported influenza in Ireland for all ages and by age-group, by week of call, from week 40 2024 to week 2 2026. Data source: Participating GP Out-of-Hours services in Ireland. Note: week number follows the ISO calendar


2.3 Confirmed cases

2.3.1 Laboratory-confirmed cases: COVID-19, influenza, RSV

4: Number of notified cases of laboratory-confirmed COVID-19, influenza and RSV by week of notification in Ireland, between week 40 2024 and week 1 2026. Data source: CIDR



2.3.2 COVID-19 seasonal trends

5: Number of notified cases of laboratory-confirmed COVID-19 by week of notification in Ireland, between week 40 2022 and week 1 2026. Data source: CIDR

Please note: where there is a 53 week year, the average of week 52 and week 53 is taken. The week labelled week 52 2025 in Figures 5, 6 and 7 have a total number of confirmed cases which is the average of the total for weeks 52 and 53 2025


2.3.3 Influenza seasonal trends

6: Number of notified cases of laboratory-confirmed influenza by week of notification in Ireland, between week 40 2022 and week 1 2026. Data source: CIDR

Please note: where there is a 53 week year, the average of week 52 and week 53 is taken. The week labelled week 52 2025 in Figures 5, 6 and 7 have a total number of confirmed cases which is the average of the total for weeks 52 and 53 2025


2.3.4 RSV seasonal trends

7: Number of notified cases of laboratory-confirmed RSV by week of notification in Ireland, between week 40 2022 and week 1 2026. Data source: CIDR

Please note: where there is a 53 week year, the average of week 52 and week 53 is taken. The week labelled week 52 2025 in Figures 5, 6 and 7 have a total number of confirmed cases which is the average of the total for weeks 52 and 53 2025


Table 1: Number and incidence of notified laboratory-confirmed cases of COVID-19, influenza and RSV by age, sex and HSE Health Region Ireland, week 1 2026. Data source: CIDR

Number of cases (incidence per 100,000 population)

All pathogens

COVID-19

Influenza

RSV

Cases

2,588 (50.3)

195 (3.8)

1,811 (35.2)

582 (11.3)

Age groups (years)

<1

219 (378.9)

19 (32.9)

73 (126.3)

127 (219.7)

1-4

286 (120.4)

20 (8.4)

137 (57.7)

129 (54.3)

5-14

147 (20.5)

15 (2.1)

110 (15.3)

22 (3.1)

15-44

490 (23.7)

41 (2.0)

391 (18.9)

58 (2.8)

45-64

351 (27.1)

21 (1.6)

274 (21.2)

56 (4.3)

65-79

558 (93.7)

39 (6.6)

410 (68.9)

109 (18.3)

≥80

537 (296.6)

40 (22.1)

416 (229.8)

81 (44.7)

Median age (IQR)

56 (14-77)

49 (10-75)

60 (24-79)

20 (1-69)

Sex

Male

1,189 (46.7)

87 (3.4)

823 (32.3)

279 (11.0)

Female

1,394 (53.5)

108 (4.1)

985 (37.8)

301 (11.6)

HSE Health Regions

Dublin and North East

662 (55.8)

59 (5)

456 (38.4)

147 (12.4)

Dublin and Midlands

388 (36)

28 (2.6)

251 (23.3)

109 (10.1)

Dublin and South East

333 (34.3)

24 (2.5)

243 (25)

66 (6.8)

South West

440 (59.4)

39 (5.3)

294 (39.7)

107 (14.4)

Mid West

241 (58.3)

18 (4.4)

179 (43.3)

44 (10.7)

West and North West

518 (68.2)

27 (3.6)

383 (50.4)

108 (14.2)


An overview of the characteristics of all cases reported since the start of the season is presented in Appendix A1.


Figure 8: Incidence of influenza and RSV notified cases by week of notification in Ireland for the 2025/2026 season with comparison to the 2024/2025 season, thresholds (baseline-very high) are defined using the Moving Epidemic Method. Data source: CIDR

Further details on the Moving Epidemic Method can be found in the Technical notes.


9: Incidence of notified cases of laboratory-confirmed COVID-19, influenza and RSV by HSE Health Region for the last 12 weeks by week of notification, from week 43 2025 to week 1 2026. Data source: CIDR


10: Age and sex-specific incidence of notified cases of laboratory-confirmed COVID-19, influenza and RSV in Ireland, from week 40 2025 to week 1 2026. Data source: CIDR

Please note that the scale on the x-axis may differ by pathogen, to account for differences in the number of cases notified for each pathogen.


11: Incidence of notified cases of laboratory-confirmed COVID-19, influenza and RSV in Ireland, by age group and week of notification, from week 40 2024 to week 1 2026. Data source: CIDR


3 Severity and impact

3.1 Sentinel Severe Acute Respiratory Infection (SARI) surveillance

3.1.1 SARI cases numbers by site

12: Number of SARI hospitalised cases by ISO week of hospital admission in Ireland, from week 40 2025 to week 2 2026. Data source: Sentinel SARI surveillance system. Note: week number follows the ISO calendar

Note: In weeks 41,49,52 2025 and week 1,2 2026 one or more SARI hospital sites did not report data.

3.1.2 Incidence rate hospital admissions

13: SARI age-specific incidence rates per 1,000 hospital admissions by ISO week of hospital admission in Ireland, from week 40 2025 to week 2 2026. Data source: Sentinel SARI surveillance system. Note: week number follows the ISO calendar

*SARI cases are recruited from emergency department admissions only in SVUH, SJH and UHL. In CHI-C cases are recruited from emergency department and non-emergency department routes (e.g. transfer from other hospitals, direct admission to speciality wards), excluding day cases and elective admissions.

Note: In weeks 41,49,52 2025 and week 1,2 2026 one or more SARI hospital sites did not report data.


14: Percentage of SARI cases with a positive laboratory test result for SARS-CoV-2, influenza or RSV by ISO week of hospital admission in Ireland, from week 40 2025 to week 2 2026. Data source: Sentinel SARI surveillance system. Note: week number follows the ISO calendar

Note: In weeks 41,49,52 2025 and week 1,2 2026 one or more SARI hospital sites did not report data.


3.2 Emergency department cases

3.2.1 Incidence of emergency department cases

15: Incidence of emergency department cases of laboratory-confirmed COVID-19, influenza and RSV by week of notification in Ireland, from week 40 2024 to week 1 2026. Data source: CIDR


3.2.2 Number of emergency department cases


16: Number of emergency department cases of laboratory-confirmed COVID-19, influenza and RSV by week of notification in Ireland, from week 40 2024 to week 1 2026. Data source: CIDR


3.3 Hospital admissions

3.3.1 Incidence of hospitalised cases


17: Incidence of hospitalised cases of laboratory-confirmed COVID-19, influenza and RSV by week of notification in Ireland, from week 40 2024 to week 1 2026. Data source: CIDR


3.3.2 Number of hospitalised cases


18: Number of hospitalised cases of laboratory-confirmed COVID-19, influenza and RSV by week of notification in Ireland, from week 40 2024 to week 1 2026. Data source: CIDR


Table 2: Number and incidence of hospitalised cases of laboratory-confirmed COVID-19, influenza and RSV by age, sex and HSE Health Region Ireland, week 1 2026. Data source: CIDR

Number of cases (incidence per 100,000 population)

All pathogens

COVID-19

Influenza

RSV

Cases

643 (12.5)

62 (1.2)

429 (8.3)

152 (3.0)

Age groups (years)

<1

38 (65.7)

4 (6.9)

8 (13.8)

26 (45.0)

1-4

70 (29.5)

7 (2.9)

28 (11.8)

35 (14.7)

5-14

30 (4.2)

7 (1.0)

19 (2.7)

4 (0.6)

15-44

60 (2.9)

8 (0.4)

41 (2.0)

11 (0.5)

45-64

84 (6.5)

3 (0.2)

64 (4.9)

17 (1.3)

65-79

176 (29.6)

15 (2.5)

123 (20.7)

38 (6.4)

≥80

185 (102.2)

18 (9.9)

146 (80.7)

21 (11.6)

Median age (IQR)

68 (26-81)

67 (10-81)

73 (52-83)

44 (1-71)

Sex

Male

317 (12.5)

35 (1.4)

204 (8.0)

78 (3.1)

Female

326 (12.5)

27 (1.0)

225 (8.6)

74 (2.8)

HSE Health Regions

Dublin and North East

68 (5.7)

10 (0.8)

36 (3)

22 (1.9)

Dublin and Midlands

92 (8.5)

11 (1)

60 (5.6)

21 (1.9)

Dublin and South East

64 (6.6)

3 (0.3)

43 (4.4)

18 (1.9)

South West

145 (19.6)

12 (1.6)

92 (12.4)

41 (5.5)

Mid West

109 (26.4)

10 (2.4)

73 (17.7)

26 (6.3)

West and North West

163 (21.5)

16 (2.1)

123 (16.2)

24 (3.2)


An overview of the characteristics of all hospitalised cases reported since the start of the season is presented in Appendix A2.


19: Age and sex-specific incidence of hospitalised cases of laboratory-confirmed COVID-19, influenza and RSV in Ireland, from week 40 2025 to week 1 2026. Data source: CIDR

Please note that the scale on the x-axis may differ by pathogen, to account for differences in the number of cases notified for each pathogen.


20: Incidence of hospitalised cases of laboratory-confirmed COVID-19, influenza and RSV by age group in Ireland, from week 40 2024 to week 1 2026. Data source: CIDR


3.3.3 Bed occupancy in acute inpatient settings

3.3.3.1 Number of acute hospital beds occupied last 30 days

21: Daily number of acute hospital beds occupied by patients with laboratory-confirmed COVID-19, influenza and RSV in Ireland in the last 30 days. Data source: HSE Planning and Performance Unit


3.3.3.2 Number of acute hospital beds occupied week 40, 2024 onwards

22: Daily number of acute hospital beds occupied by patients with laboratory-confirmed COVID-19, influenza and RSV in Ireland from week 40 2024 to week 2 2026. Note: week number follows the ISO calendar. Data source: HSE Planning and Performance Unit


3.4 Intensive Care Unit (ICU) admissions


23: Number of ICU admissions due to laboratory-confirmed COVID-19, influenza and RSV by week of admission to ICU in Ireland, week 40 2024 to week 1 2026. Data source: CIDR


Table 3: Number and incidence of ICU admissions due to COVID-19, influenza and RSV in Ireland by week of admission to ICU, week 1 2026, and season to date (from week 40 2025 to week 1 2026). Data source: CIDR

Week 1, 2026

Week 40, 2025 to week 1, 2026

Number of ICU admissionsa

ICU admissions per 1,000 hospitalisations

% of hospitalised cases admitted to ICU

Number of ICU admissions

ICU admissions per 1,000 hospitalisations

% of hospitalised cases admitted to ICU

COVID-19

1

16.1

1.6

20

16.7

1.7

Influenza

5

11.7

1.2

140

30.9

3.1

RSV

0

0.0

0.0

46

37.1

3.7

aICU admissions include all cases admitted to ICU due to COVID-19, influenza and RSV


3.5 Mortality

3.5.1 Deaths among confirmed cases


24: Number of COVID-19, influenza and RSV deaths by week of death in Ireland, week 40 2024 to week 1 2026. Data source: CIDR


Table 4: Number and incidence of COVID-19, influenza and RSV deaths in Ireland, for the season to date (from week 40 2025 to week 1 2026). Data source: CIDR

COVID-19

Influenza

RSV

Age (years)

Number of deaths

Incidence per 100,000 population

Number of deaths

Incidence per 100,000 population

Number of deaths

Incidence per 100,000 population

<65

3

0.1

7

0.2

0

0.0

≥65

62

8.0

60

7.7

6

0.8

Total

65

1.3

67

1.3

6

0.1


4 Outbreaks


25: Number of COVID-19, influenza, RSV and other ARI outbreaks reported in health and care settings by week outbreak reported in Ireland, from week 40 2024 to week 1 2026. Data source: CIDR


Table 5: Number of COVID-19, influenza, RSV and other ARI outbreaks reported by setting in Ireland, week 1 2026 and the season to date (from week 40 2025 to week 1 2026). Data source: CIDR

Week 1 2026

Outbreak location

COVID-19

Influenza

RSV

ARI

Total week 1, 2026

Total week 40, 2025 to week 1, 2026

Comm. hosp/long-stay unit

0

6

0

0

6

44

Hospital

1

11

2

0

14

190

Nursing home

2

23

3

10

38

269

Other healthcare service

0

3

0

0

3

10

Residential institution

0

4

0

2

6

63

Total health care settings

3

47

5

12

67

576

Total non health care settings

0

1

0

0

1

7

Total

3

48

5

12

68

583


26: Number of COVID-19, influenza, RSV and other ARI outbreaks by HSE Health Region, Ireland week 1 2026. Data source: CIDR


5 Virology and genomic surveillance

5.1 Virus test positivity and dominant virus types/subtypes in circulation


Table 6: Number and percentage positive SARS-CoV-2, influenza and RSV specimens by surveillance source Ireland, week 2 2026. Data source: NVRL. Note: week number follows the ISO calendar

SARS-CoV-2

Influenza

RSV

Surveillance system

Total tested

Total positive

% positive

Total positive

% positive

Total positive

% positive

NVRL Sentinel GP ARI

167

2

1.2

41

24.6

23

13.8

NVRL non-sentinel respiratory

308

3

1.0

52

16.9

10

3.2


27: Sentinel GP ARI specimens and non-sentinel respiratory specimen test positivity for SARS-CoV-2, influenza, RSV and other respiratory viruses by week of specimen collection in Ireland, week 21 2025 to week 2 2026. PIV = parainfluenza viruses. Data source: NVRL. Note: week number follows the ISO calendar


28: Number of sentinel GP ARI and non-sentinel respiratory influenza positive specimens and laboratory-confirmed influenza notifications by influenza type/sub-type and by week of specimen collection in Ireland, week 40 2024 to ISO week 2 2026 / Epi week 1 2026. Data source: NVRL, CIDR


Underlying data on the total number of tests, total number of positives and percentage positive by week and for the season to date for each virus for both sentinel and non-sentinel specimens are presented in Appendix A3, Appendix A4, Appendix A5, Appendix A6


5.2 SARS-CoV-2 genomic data


29: SARS-CoV-2 whole genome sequencing results by week of specimen collection in Ireland, from week 40 2024 to week 46 2025


Note: There is typically a lag time of 1-3 weeks between a case being notified, selected for sequencing and sequencing being completed. This may be longer when there is a lower number of cases due to batching of specimens. Therefore, the percentage of cases notified in this time period who are ultimately sequenced will be higher than reported here.


30: SARS-CoV-2 whole genome sequencing results by week of specimen collection in Ireland, from week 42 2025 to week 46 2025


6 SARS-CoV-2 wastewater surveillance


31: Approximate location of wastewater catchment areas and SARS-CoV-2 viral loads (gc/day) in wastewater and percentage change compared to previous week, National Wastewater Surveillance Programme Ireland, week 1 2026


Figure 32: Weekly distribution of population-normalised SARS-CoV-2 viral load (gc/day/person), National Wastewater Surveillance Programme Ireland, May 2021 to week 1 2026


9 Technical notes

General

Data are provisional and subject to ongoing review, validation and update. As a result, figures in this report may differ from previously published figures.

The weekly calendar runs from Sunday to Saturday for respiratory virus notifications on CIDR (as per the Infectious Disease Regulations 1982 and subsequent amendments) and Monday to Sunday for the sentinel GP and SARI surveillance systems (as per ISO week). Further information on epidemiological dates and weeks can be found on the HPSC website.

Please note that the excess mortality data are provisional due to the time delay with death registration in Ireland. A country-specific adjustment function was applied to correct for the typical delay in registrations of deaths in Ireland. Nonetheless, estimates of excess mortality for the most recent weeks are reported with some uncertainty and should be interpreted with caution.

Definitions

The case definitions for COVID-19, influenza and RSV are available here. Only data on laboratory-confirmed cases, including cases diagnosed using near patient molecular tests, are included in this report.

Sentinel GP ARI consultations are consultations to sentinel GP practices for Acute Respiratory Infection (ARI), with ARI defined as Sudden onset of symptoms AND at least one of the following four respiratory symptoms: Cough, sore throat, shortness of breath, coryza AND a clinician’s judgement that the illness is due to an infection.

Sentinel GP ILI consultations are consultations to sentinel GP practices for Influenza like illness (ILI), with ILI defined as Sudden onset of symptoms AND at least one of the following four respiratory symptoms: Fever or feverishness, malaise, headache, myalgia AND at least one of the following three respiratory symptoms: Cough, sore throat, shortness of breath.

GP out of hours calls refer to calls to GP out of hours services from persons with self-reported clinical symptoms of ‘flu’ or ‘cough’.

Emergency Department cases refer to cases treated in emergency departments, with no indication on CIDR that they have subsequently been admitted to hospital.

Hospitalised cases are inpatients with laboratory-confirmed SARS-CoV-2, influenza or RSV and includes inpatients with incidental infections, where the infection is not the reason for their admission.

Bed occupancy refers to the number of laboratory-confirmed cases admitted to acute inpatient sites at 08:00 hrs on the day of reporting.

A SARI case is defined as a person hospitalised for at least 24 hours with acute respiratory infection and onset of symptoms within 14 days prior to hospital admission, with at least one of the following symptoms: cough, fever, shortness of breath OR sudden onset of anosmia, ageusia or dysgeusia.

The case definition was adapted in Ireland for infants aged <6 months to include increased work of breathing and apnoea as relevant symptoms, the revised definition was applied to cases admitted from week 40 2025. A SARI case refers to an individual patient episode of care.

As of September 2024, ICU admissions for COVID-19, influenza and RSV refer to those admitted to intensive care where COVID-19, influenza or RSV were the primary or contributory cause of admission. Prior to September 2024, ICU admissions for influenza and RSV included all admissions where the patient tested positive for influenza or RSV, irrespective of whether these pathogens were the cause of admission.

COVID-19, influenza and RSV deaths are defined as a death in a person with laboratory-confirmed COVID-19, influenza or RSV infection. see case definitions (this includes cases detected postmortem)

Moving Epidemic Method (MEM) thresholds have been established to assess the intensity of respiratory virus activity. Thresholds have been calculated using five years of historical notification data from 2017/2018 to 2024/2025. The seasons 2020/2021 and 2021/2022 were excluded, due to low influenza and RSV in circulation during the COVID-19 pandemic. SARS-CoV-2 has a bimodal epidemic pattern and therefore is unsuitable for threshold analysis using the MEM. Further details

Test Positivity: Positive tests refer to all positive specimens and includes duplicates and individuals who were re-tested.

Outbreaks are defined as two or more cases of acute respiratory infection with the same pathogen (SARS-CoV-2, influenza or respiratory syncytial virus (RSV)) confirmed by a laboratory test or near patient test carried out by a health professional, and where there is reason to consider that these cases may be epidemiologically linked in place and time.

Other Acute Respiratory Infection (ARI) outbreaks are defined as: Two or more cases of acute respiratory infection arising within the same 48hr period epidemiologically linked in place: Outbreaks are classified as Suspect ARI outbreaks, where testing has not been completed, is pending or has been negative for Influenza, RSV and SARS-CoV-2. Outbreaks are classified as confirmed if other respiratory pathogens (ORVs), e.g. Rhinovirus, hMPV, Coronavirus OC43 etc are identified via laboratory confirmation. The outbreak data presented in this report includes both confirmed and suspect outbreaks.

Variant working definitions for ‘SARS-CoV-2 variants of concern’ (VOC), ‘SARS-CoV-2 variants of interest’ (VOI) and ‘SARS-CoV-2 variants under monitoring’ (VUM) are available on the WHO website and ECDC website.

Data sources

The Computerised Infectious Disease Reporting (CIDR) system: CIDR is the source of statutory notification data on laboratory-confirmed COVID-19, influenza, RSV (including data on notified, emergency department, hospitalised and ICU cases and data on cases who died) and data on outbreaks.

The type/subtype of laboratory-confirmed influenza notifications are reported on the CIDR system. The number of cases hospitalised and admitted to ICU described in this report relate only to cases notified during this reporting period, with known hospitalisation/ICU status at the time of reporting.

Regional Departments of Public Health currently prioritise the investigation and reporting of outbreaks in settings that benefit most from public health and clinical intervention. The outbreak data reported here focuses on these key settings/groups. These settings include acute hospitals, nursing homes, community hospital/long-stay units, residential institutions (centres for disabilities, centres for older people, children’s/TUSLA residential centres and mental health facilities) and other healthcare settings.

Population denominator data for analyses of CIDR data on notified, emergency department, hospitalised and ICU cases and deaths are taken from Census 2022.

Sentinel GP surveillance system: This includes 100 participating general practices (located in all HSE Health Regions). These practices report electronically on a weekly basis, the number of patients who consulted with acute respiratory infection (ARI) and influenza-like illness (ILI) (identified using International Classification of Primary Care 2 codes R74 and R80). These practices provide overall and age-stratified denominator data on the number of registered patients who have sought care at the practice during the previous three years. The combined patient population in these practices is estimated to be approximately 10% of the national population. Sentinel GPs take a combined nose and throat swab from the first five patients attending their practice each week who meet the ARI case definition and send these to the NVRL for testing.

GP Out-of-hours (GPOOHs) services: Five out of 14 GPOOHs services provide weekly data on the total and age-stratified number of out of hours calls for 1) all reasons, 2) for self-reported cough and 3) for self-reported flu. The denominator for calculations of percentage of calls is the total number of calls for all reasons.

The HSE Performance Management and Improvement Unit (PMIU) provides daily data on bed occupancy (the number of currents inpatients with laboratory-confirmed COVID-19, influenza and RSV).

Severe Acute Respiratory Infections (SARI) surveillance system: SARI cases are identified based on clinical symptoms from new admissions through the Emergency Department in SVUH, SJH and UHL. In CHI-C cases are recruited from emergency department and non-emergency department routes (e.g. transfer from other hospitals, direct admission to speciality wards), excluding day cases and elective admissions.

National Virus Reference Laboratory (NVRL): The NVRL routinely test sentinel GP and non-sentinel respiratory specimens for SARS-CoV-2, influenza, RSV and a panel of other seasonal respiratory viruses (ORV). The NVRL report on influenza type/subtype of sentinel GP ARI and non-sentinel respiratory specimens on a weekly basis.

The SARS-CoV-2 genomic sequencing sampling framework currently focuses on notified COVID-19 cases with severe disease (hospitalisation, ICU admission) and deaths, COVID-19 outbreaks in health and care settings, sentinel surveillance programmes in the community and acute hospitals and targeted sequencing based on public health risk assessment/clinical requests and virological changes e.g. new variant of concern. There is typically a lag time of 1-3 weeks between a COVID-19 case being notified, selected for sequencing and SARS-CoV-2 sequencing being completed. Therefore, the proportion of notified COVID-19 cases notified in this time period from whom specimens are ultimately sequenced will be higher than currently reported here. The HPSC link sequencing results received from laboratories to epidemiological data on COVID-19 cases reported on the CIDR system. This report summarises WGS results and epidemiological data for COVID-19 cases that have been sequenced in Ireland since week 40 2024 (specimen dates between 29/09/2024 and 15/11/2025). The SARS-CoV-2 sequencing results included in this report reflect all data available as of 29/12/2025.

National SARS-CoV-2 Wastewater Surveillance Programme: A detailed description of the process involved for wastewater collection, sampling and analyses is available in the routinely published [National SARS-CoV-2 Wastewater Surveillance Programme Report] (https://www.hpsc.ie/a-z/nationalwastewatersurveillanceprogramme/)


10 Appendix

Appendix Table 1: Number and incidence of notified laboratory-confirmed cases of COVID-19, influenza and RSV by age, sex and HSE Health Region, from week 40 2025, to week 1 2026. Data source: CIDR

Number of cases (incidence per 100,000 population)

All pathogens

COVID-19

Influenza

RSV

Cases

27,014 (524.6)

3,310 (64.3)

19,965 (387.7)

3,739 (72.6)

Age groups (years)

<1

1,635 (2,828.9)

204 (353.0)

719 (1,244.0)

712 (1,231.9)

1-4

4,372 (1,839.9)

202 (85.0)

2,597 (1,092.9)

1,573 (662.0)

5-14

3,143 (438.4)

194 (27.1)

2,743 (382.6)

206 (28.7)

15-44

5,745 (277.9)

541 (26.2)

4,924 (238.2)

280 (13.5)

45-64

3,152 (243.7)

510 (39.4)

2,403 (185.8)

239 (18.5)

65-79

4,675 (785.3)

811 (136.2)

3,481 (584.8)

383 (64.3)

>80

4,289 (2,369.3)

848 (468.4)

3,095 (1,709.7)

346 (191.1)

Median age (IQR)

36 (6-73)

65 (30-80)

36 (10-73)

2 (1-48)

Sex

Male

12,502 (491.3)

1,559 (61.3)

9,049 (355.6)

1,894 (74.4)

Female

14,482 (556.0)

1,751 (67.2)

10,893 (418.2)

1,838 (70.6)

HSE Health Regions

Dublin and North East

6,270 (528.2)

705 (59.4)

4824 (406.4)

741 (62.4)

Dublin and Midlands

5,014 (465.3)

577 (53.5)

3790 (351.7)

647 (60)

Dublin and South East

5,511 (567.5)

764 (78.7)

4146 (426.9)

601 (61.9)

South West

4,068 (549.3)

567 (76.6)

2825 (381.4)

676 (91.3)

Mid West

2,046 (495.3)

302 (73.1)

1439 (348.4)

305 (73.8)

West and North West

4,096 (539.2)

394 (51.9)

2934 (386.2)

768 (101.1)


Appendix Table 2: Number and incidence of notified hospitalised laboratory-confirmed cases of COVID-19, influenza and RSV by age, sex and HSE Health Region from week 40 2025 to week 1 2026. Data source: CIDR

Number of cases (incidence per 100,000 population)

All pathogens

COVID-19

Influenza

RSV

Cases

6,973 (135.4)

1,196 (23.2)

4,536 (88.1)

1,241 (24.1)

Age groups (years)

<1

516 (892.8)

81 (140.1)

196 (339.1)

239 (413.5)

1-4

1,248 (525.2)

87 (36.6)

637 (268.1)

524 (220.5)

5-14

809 (112.9)

81 (11.3)

643 (89.7)

85 (11.9)

15-44

793 (38.4)

126 (6.1)

603 (29.2)

64 (3.1)

45-64

699 (54.0)

146 (11.3)

471 (36.4)

82 (6.3)

65-79

1,483 (249.1)

329 (55.3)

1,013 (170.2)

141 (23.7)

>80

1,424 (786.6)

346 (191.1)

972 (536.9)

106 (58.6)

Median age (IQR)

50 (4-77)

70 (31-81)

55 (8-78)

2 (1-53)

Sex

Male

3,376 (132.7)

621 (24.4)

2,106 (82.8)

649 (25.5)

Female

3,592 (137.9)

575 (22.1)

2,426 (93.1)

591 (22.7)

HSE Health Regions

Dublin and North East

772 (65)

167 (14.1)

486 (40.9)

119 (10)

Dublin and Midlands

1,119 (103.8)

239 (22.2)

712 (66.1)

168 (15.6)

Dublin and South East

1,560 (160.6)

235 (24.2)

1054 (108.5)

271 (27.9)

South West

955 (128.9)

191 (25.8)

575 (77.6)

189 (25.5)

Mid West

1,018 (246.5)

160 (38.7)

667 (161.5)

191 (46.2)

West and North West

1,546 (203.5)

204 (26.9)

1039 (136.8)

303 (39.9)


Appendix Table 3: Number and percentage of test positive Sentinel GP ARI specimens by respiratory virus for the most recent two weeks 1 2026, week 2 2026 and the 2025/2026 season to date. Data source: NVRL. Note: week number follows the ISO calendar

Week 1 2026 (N = 157)

Week 2 2026 (N = 167)

2025/2026 (N = 2839)

Virus

Total positive

% positive

Total positive

% positive

Total positive

% positive

SARS-CoV-2

1

0.6

2

1.2

96

3.4

Influenza Virus

64

40.8

41

24.6

950

33.5

Respiratory Syncytial Virus (RSV)

11

7.0

23

13.8

123

4.3

Rhino/enterovirus

9

5.7

15

9.0

433

15.3

Adenovirus

0

0.0

0

0.0

22

0.8

Bocavirus

1

0.6

1

0.6

9

0.3

Parainfluenza virus type 1 (PIV-1)

2

1.3

1

0.6

17

0.6

Parainfluenza virus type 2 (PIV-2)

0

0.0

0

0.0

0

0.0

Parainfluenza virus type 3 (PIV-3)

4

2.5

1

0.6

20

0.7

Parainfluenza virus type 4 (PIV-4)

0

0.0

0

0.0

45

1.6


Appendix Table 4: Number and percentage positive NVRL non-sentinel respiratory specimens by respiratory virus, week 1 2026, week 2 2026 and the 2025/2026 season to date. Data source: NVRL. Note: week number follows the ISO calendar

Week 1 2026 (N = 337)

Week 2 2026 (N = 308)

2025/2026 (N = 5309)

Virus

Total positive

% positive

Total positive

% positive

Total positive

% positive

SARS-CoV-2

2

0.6

3

1.0

125

2.4

Influenza Virus

59

17.5

52

16.9

1,349

25.4

Respiratory Syncytial Virus (RSV)

22

6.5

10

3.2

339

6.4

Rhino/enterovirus

27

8.0

22

7.1

619

11.7

Adenovirus

3

0.9

1

0.3

37

0.7

Bocavirus

1

0.3

1

0.3

19

0.4

Parainfluenza virus type 1 (PIV-1)

2

0.6

3

1.0

21

0.4

Parainfluenza virus type 2 (PIV-2)

0

0.0

0

0.0

2

0.0

Parainfluenza virus type 3 (PIV-3)

3

0.9

4

1.3

44

0.8

Parainfluenza virus type 4 (PIV-4)

1

0.3

0

0.0

39

0.7


Appendix Table 5: Influenza type and sub-type distribution among sentinel GP ARI and non-sentinel respiratory influenza positive specimens for the most recent two weeks 1 2026, week 2 2026 and the 2025/2026 season to date. Data source: NVRL. Note: week number follows the ISO calendar

Influenza A

Influenza B

Time period

Specimen source

Total influenza positive

Total

A(H1)pdm09

A(H3)

A(not subtyped)

Total

B Victoria

B (unspecified)

Week 1 2026

Sentinel GP ARI

64

64

3

61

0

0

0

0

Non-sentinel respiratory

59

59

5

54

0

0

0

0

Total

123

123

8

115

0

0

0

0

Week 2 2026

Sentinel GP ARI

41

40

6

34

0

1

0

1

Non-sentinel respiratory

52

51

6

45

0

1

0

1

Total

93

91

12

79

0

2

0

2

Season to date

Sentinel GP ARI

950

948

54

893

1

2

0

2

Non-sentinel respiratory

1,349

1,346

179

1,151

16

3

1

2

Total

2,299

2,294

233

2,044

17

5

1

4


Appendix Table 6: RSV type distribution among sentinel GP ARI and non-sentinel respiratory RSV positive specimens for the most recent two weeks 1 2026, week 2 2026 and the 2025/2026 season to date. Data source: NVRL. Note: week number follows the ISO calendar

Time period

Specimen source

Total RSV positive

RSV A

RSV B

RSV (unspecified)

Week 1 2026

Sentinel GP ARI

11

3

8

0

Non-sentinel respiratory

22

13

9

0

Total

33

16

17

0

Week 2 2026

Sentinel GP ARI

23

9

14

0

Non-sentinel respiratory

10

5

5

0

Total

33

14

19

0

Season to date

Sentinel GP ARI

123

54

69

0

Non-sentinel respiratory

339

198

141

0

Total

462

252

210

0