Weekly Report on Severe Acute Respiratory Infections (SARI), Ireland

Week 32 2026 (week ending 09/08/2026)

Report prepared on 12/08/2026


1 About this report

SARI surveillance uses the ISO week date system, in which each week runs from Monday to Sunday. This differs from the week definition used in the national infectious disease notification system in Ireland, where weeks run from Sunday to Saturday. Because of this difference, the ISO week calendar (SARI) did not include a Week 53 in 2025, whereas the notification system did. For details of ISO weeks in 2026, see ISO Weeks Calendar.

Since week 40 2025, four sentinel hospital sites are participating in Ireland’s severe acute respiratory infections (SARI) surveillance programme. The most recent addition is Children’s Health Ireland at Crumlin (CHI-C), commencing on 29th September 2025. St Vincent’s University Hospital (SVUH) was the first site to join, commencing SARI surveillance on 5th July 2021. This was followed by St James’s Hospital (SJH) and University Hospital Limerick (UHL, paediatric cases only) both commenced on 30th September 2024 (Week 40 2024).

The data presented in this report were extracted from the HPSC SARI surveillance database on 12/08/2026. These figures are provisional and subject to ongoing review, validation and updates. Consequently, they may differ from previously published data as refinements are made to improve accuracy.

Three of the four SARI sentinel hospital sites (75%) reported data for the current ISO week (W32 2026). Variations in the number of sentinel sites reporting each week, should be considered when comparing incidence rates and case numbers from previous weeks.

2 Key message

In ISO week 32 2026, SARI activity was stable and remained at low levels in Ireland; 44 SARI cases were reported from three of the four sentinel hospital sites. No cases tested positive for SARS-CoV-2, influenza or RSV.

3 Summary

Note: Data presented below relate to ISO week

SARI case numbers (week 32 2026):

  • 44 SARI cases were admitted to three of the four SARI sentinel sites.

  • SARI cases <15 years: 10 cases from one sentinel site.

  • SARI cases ≥15 years: 34 cases from two sentinel sites.


SARI incidence:

The incidence rates per 1,000 hospital admissions* were as follows:

  • All SARI cases: 58.0 in week 32 2026, compared to 47.4 in week 31 2026.

  • SARI cases <15 years: 93.5 in week 32 2026, compared to 100.6 in week 31 2026.

  • SARI cases ≥15 years: 52.1 in week 32 2026, compared to 33.9 in week 31 2026.

*See technical notes section for further information on SARI hospital admissions data


Age profile (week 32 2026): 45.5% (n=20) cases were aged ≥65 years and 13.6% (n=6) cases aged <5 years:

  • All SARI cases: median age 61 years; IQR: 43-76 years.

  • SARI cases <15 years: median age 4 years, IQR: 1-6 years.

  • SARI cases ≥15 years: median age 72 years, IQR: 59-79 years.


Virus test positivity among SARI cases (week 32 2026): Among those tested (93.2%, n=41):

  • No cases tested positive for SARS-CoV-2, compared to 2.6% (n=1) in week 31 2026.

  • No cases tested positive for influenza in weeks 31 and 32 2026.

  • No cases tested positive for RSV, compared to 7.7% (n=3) in week 31 2026.


Genomic surveillance (week 21 2026 to week 32 2026): Among SARI SARS-CoV-2 positive specimens sequenced (n=3), XFG was the dominant variant at 100% (n=3). Currently, three samples are awaiting sequencing, and two samples could not be sequenced.


Influenza typing/subtyping (week 21 2026 to week 32 2026): Of those tested (n=592), 1.2% (n=7) were positive for influenza A which was the predominant virus among influenza positive SARI admissions, and 0.0% were positive for influenza B. Among the influenza A samples that were subtyped, 14.3% (n=1) were A(H3) and 85.7% (n=6) were A(H1)pdm09. No cases are awaiting subtyping.


RSV typing (week 21 2026 to week 32 2026): Among those typed (n=9), 22.2% (n=2) were RSV A and 77.8% (n=7) RSV B. Currently, three samples are awaiting typing, or could not be typed.


Underlying medical conditions (week 32 2026): Overall 86.4% (n=38) of SARI cases reported at least one underlying medical condition. This included 80.0% (n=8) of cases among those aged <15 years and 88.2% (n=30) among those aged ≥15 years.


Severe outcomes (week 21 2026 to week 32 2026):

  • 5.9% (n=32) of SARI cases were admitted to ICU, this included 7.8% (n=21) among those aged <15 years and 4.0% (n=11) among those aged ≥15 years of age. Overall, the median length of stay was 4 days, IQR 2-9 days. Among the SARI cases admitted to ICU, 3.1% (n=1) were positive for SARS-CoV-2 only, none for influenza or RSV only, and 3.1% (n=1) were positive for more than one virus.

  • 1.9% (n=12) of SARI cases died in hospital. The median age was 79.5 years, IQR 57.5-91.5 years, 58.3% (n=7) were ≥65 years of age.


Vaccination status (week 21 2026 to week 31 2026): These data are reported with a one-week time lag.

  • Amongst SARI cases positive for SARS-CoV-2 and eligible for vaccination (n=6), 100% (n=6) had NOT received a COVID-19 vaccine dose in the six months prior to the reported episode of illness.

4 SARI case numbers and incidence rates

4.1 SARI cases by site

Number of SARI cases by sentinel hospital site and by week of admission W32 2025-W32 2026

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

4.2 Incidence admissions

SARI age-specific incidence rates per 1,000 hospital admissions by week of admission W32 2025-W32 2026

*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: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

4.3 SARI cases by age group

Number of SARI cases by age group and week of admission W32 2025-W32 2026

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

4.4 Incidence (seasons)

SARI incidence rates per 1,000 hospital admissions by week of admission between week 40 2024 and week 32 2026

Note: In the 2024/2025 season three hospital sites (SVUH, SJH & UHL) participated, and four sites (SVUH, SJH, UHL & CHI-C) participated in season 2025/2026.

5 Demographics

Table 1: Number and proportion of SARI cases by sex and age, for the current week (week 32 2026), last four weeks (week 29 2026 to week 32 2026) and current season (week 21 2026 to week 32 2026)

Current week

Last four weeks

Summer season total

W32 2026

W29 2026-W32 2026

W21 2026-W32 2026

Characteristic

Category

N = 44

N = 181

N = 628

Gender

Female

19 (43.2)

86 (47.5)

304 (48.4)

Male

25 (56.8)

95 (52.5)

324 (51.6)

Age <15 years (in years)

Median (IQR)

4 (1 - 6)

1 (0 - 4)

2 (1 - 4)

Range

0 - 14

0 - 14

0 - 14

Age ≥15 years (in years)

Median (IQR)

72 (59 - 79)

71 (60 - 79)

72 (61 - 81)

Range

41 - 97

19 - 97

19 - 97

Age groups (years)

<1

1 (2.3)

23 (12.7)

69 (11.0)

1-4

5 (11.4)

37 (20.4)

144 (22.9)

5-14

4 (9.1)

14 (7.7)

71 (11.3)

15-34

0 (0.0)

2 (1.1)

10 (1.6)

35-64

14 (31.8)

35 (19.3)

97 (15.4)

65-79

12 (27.3)

45 (24.9)

140 (22.3)

80+

8 (18.2)

25 (13.8)

97 (15.4)

Patient residence

Residential care facility

7 (15.9)

19 (10.5)

64 (10.2)

Private residence/home

36 (81.8)

160 (88.4)

561 (89.3)

Other/unknown residence

1 (2.3)

2 (1.1)

3 (0.5)

Note: For the current week (week 32 2026), among the SARI cases aged ≥65 years, 10.0% (n=2) were resident in a residential care facility.

6 PCR testing for SARS-CoV-2, Influenza and RSV

SARI cases are tested on-site in each hospital by PCR for SARS-CoV-2, influenza and RSV on admission.

Table 2: Number and proportion of SARI cases PCR positive for SARS-CoV-2, influenza, and RSV for the current week, last four weeks (week 29 2026 to week 32 2026) and current season (week 21 2026 to week 32 2026)

Current week

Last four weeks

Summer season total

W32 2026

W29 2026-W32 2026

W21 2026-W32 2026

Overall
N = 411

<15y
N = 101

≥15y
N = 311

Overall
N = 1671

<15y
N = 661

≥15y
N = 1011

Overall
N = 5921

<15y
N = 2691

≥15y
N = 3231

SARS-CoV-2

0 (0.0)

0 (0.0)

0 (0.0)

3 (1.8)

2 (3.0)

1 (1.0)

8 (1.4)

6 (2.2)

2 (0.6)

Influenza

0 (0.0)

0 (0.0)

0 (0.0)

2 (1.2)

1 (1.5)

1 (1.0)

7 (1.2)

5 (1.9)

2 (0.6)

RSV

0 (0.0)

0 (0.0)

0 (0.0)

5 (3.0)

4 (6.1)

1 (1.0)

12 (2.0)

10 (3.7)

2 (0.6)

1n (%)

Note: Between week 21 2026 to week 32 2026, 1 SARI cases were coinfected with more than one of the three viruses under surveillance.

A further breakdown of SARI test positivity by hospital site is available in the Appendix.

6.1 Number PCR positive

Number of SARI cases PCR positive for SARS-CoV-2, influenza and RSV by week of hospital admission W32 2025-W32 2026

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

6.2 Percentage PCR positive

Percentage of SARI cases PCR positive for SARS-CoV-2, influenza, RSV and overall positivity by week of hospital admission W32 2025-W32 2026

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

6.3 Percentage PCR positive by age group

Weekly positivity rate of SARI cases PCR positive for SARS-CoV-2, influenza and RSV by age group and by week of hospital admission W32 2025-W32 2026

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season. Y-axis scale may differ for each age group.

7 SARS-CoV-2 genomic analysis

Note: There is typically a lag time of several weeks between a case being admitted, positive samples selected for sequencing and sequencing being completed and reported.

For further information on circulating variants in Ireland, see Respiratory virus notification data hub - Health Protection Surveillance Centre (hpsc.ie) and Integrated Respiratory Virus Bulletin.


7.1 SARS-CoV-2 variants by week

Number of SARS CoV-2 positive SARI cases, by variant and week of hospital admission, W32 2025-W32 2026

*Includes sub-lineage JN.1, excludes lineage KP.3.

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

8 Influenza typing/subtyping

8.1 Influenza typing/subtyping by week

Number of influenza positive SARI cases by type/subtype and by week of admission, W32 2025-W32 2026

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

9 RSV typing

9.1 RSV typing by week

Number of RSV positive SARI cases by RSV type and by week of admission, W32 2025-W32 2026

Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.

10 Symptoms

Table 4: Number and proportion of SARI cases’ clinical symptoms, either at or prior to hospital admission, for the last four weeks (week 29 2026 to week 32 2026), and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

Clinical symptoms

<15y
N = 74

≥15y
N = 107

<15y
N = 284

≥15y
N = 344

Cough

39 (52.7)

92 (86.0)

178 (62.7)

288 (83.7)

Fever

54 (73.0)

58 (54.2)

208 (73.2)

173 (50.3)

Shortness of breath

6 (8.1)

98 (91.6)

40 (14.1)

309 (89.8)

General deterioration

29 (39.2)

38 (35.5)

96 (33.8)

127 (36.9)

Coryza

36 (48.6)

4 (3.7)

142 (50.0)

11 (3.2)

Increased work of breathing

29 (39.2)

4 (3.7)

124 (43.7)

10 (2.9)

Sore throat

31 (41.9)

2 (1.9)

106 (37.3)

11 (3.2)

Nausea/Vomiting

25 (33.8)

10 (9.3)

90 (31.7)

23 (6.7)

Malaise

17 (23.0)

11 (10.3)

54 (19.0)

38 (11.0)

Diarrhoea

8 (10.8)

4 (3.7)

24 (8.5)

11 (3.2)

Headache

4 (5.4)

1 (0.9)

13 (4.6)

17 (4.9)

Acute confusion

0 (0.0)

7 (6.5)

0 (0.0)

23 (6.7)

Muscular pain

1 (1.4)

4 (3.7)

8 (2.8)

13 (3.8)

Apnoea

3 (4.1)

0 (0.0)

6 (2.1)

0 (0.0)

Sepsis

0 (0.0)

2 (1.9)

1 (0.4)

4 (1.2)

11 Underlying medical conditions and risk factors

SARI cases may be reported with one or more underlying medical conditions. Weekly proportions can be based on small numbers and vary from week to week, caution is therefore advised when interpreting changes in weekly proportions (Table 5).

Table 5: Number and proportion of SARI cases with underlying medical conditions reported on hospital admission, for the last four weeks (week 29 2026 to week 32 2026) and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

Condition

<15y
N = 74

≥15y
N = 107

<15y
N = 284

≥15y
N = 344

Number of underlying medical conditions

None

54 (73.0)

7 (6.5)

201 (70.8)

13 (3.8)

One

14 (18.9)

24 (22.4)

46 (16.2)

71 (20.6)

Two

5 (6.8)

33 (30.8)

26 (9.2)

100 (29.1)

Three or more

1 (1.4)

43 (40.2)

11 (3.9)

160 (46.5)

Conditions reported

Lung disease

3 (4.1)

49 (45.8)

15 (5.3)

170 (49.4)

Heart disease

3 (4.1)

41 (38.3)

19 (6.7)

138 (40.1)

Hypertension

0 (0.0)

33 (30.8)

3 (1.1)

120 (34.9)

Neurological disease

3 (4.1)

20 (18.7)

20 (7.0)

71 (20.6)

Cancer

0 (0.0)

22 (20.6)

1 (0.4)

74 (21.5)

Rheumatological disease

0 (0.0)

22 (20.6)

1 (0.4)

74 (21.5)

Asthma

4 (5.4)

15 (14.0)

17 (6.0)

50 (14.5)

Diabetes

0 (0.0)

17 (15.9)

1 (0.4)

55 (16.0)

Immunocompromised

0 (0.0)

9 (8.4)

1 (0.4)

32 (9.3)

Intellectual disability

6 (8.1)

0 (0.0)

25 (8.8)

6 (1.7)

Dementia

0 (0.0)

7 (6.5)

0 (0.0)

28 (8.1)

Kidney disease

1 (1.4)

10 (9.3)

3 (1.1)

23 (6.7)

Liver disease

1 (1.4)

4 (3.7)

1 (0.4)

17 (4.9)

Prematurity*

6 (8.1)

0 (0.0)

17 (6.0)

0 (0.0)

Obesity

0 (0.0)

5 (4.7)

0 (0.0)

14 (4.1)

Down syndrome

0 (0.0)

0 (0.0)

8 (2.8)

2 (0.6)

Cystic fibrosis

0 (0.0)

1 (0.9)

0 (0.0)

4 (1.2)

Long COVID

0 (0.0)

0 (0.0)

0 (0.0)

1 (0.3)

Tuberculosis

0 (0.0)

0 (0.0)

0 (0.0)

1 (0.3)

*Prematurity: birth before 37 weeks gestation, this applies to paediatric cases under 2 years of age only.

12 Clinical course

12.1 Complications

Information on the clinical course during hospitalisation is only available after patient discharge, and there may be a delay between discharge and data collection, due to the manual data collection methods required. Furthermore, data collection is ongoing for those not yet discharged from hospital.

SARI cases could be reported with one or more complications; among those for whom discharge information is available the most common complication reported was pneumonia (Table 6).

Table 6: Number and proportion of SARI cases and complications among discharged SARI cases, for the last four weeks (week 29 2026 to week 32 2026), and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

Complication

<15y
N = 53

≥15y
N = 35

<15y
N = 262

≥15y
N = 248

No complications

27 (50.9)

7 (20.0)

126 (48.1)

36 (14.5)

Pneumonia

8 (15.1)

26 (74.3)

54 (20.6)

171 (69.0)

Bronchiolitis

6 (11.3)

0 (0.0)

41 (15.6)

0 (0.0)

Respiratory complications

0 (0.0)

0 (0.0)

6 (2.3)

21 (8.5)

Sepsis

1 (1.9)

2 (5.7)

4 (1.5)

13 (5.2)

Acute kidney injury

0 (0.0)

1 (2.9)

2 (0.8)

14 (5.6)

Heart failure

0 (0.0)

3 (8.6)

0 (0.0)

16 (6.5)

ARDS

0 (0.0)

0 (0.0)

2 (0.8)

2 (0.8)

Secondary bacterial infections

0 (0.0)

0 (0.0)

1 (0.4)

2 (0.8)

Acute atrial fibrillation

0 (0.0)

0 (0.0)

0 (0.0)

3 (1.2)

Multi organ failure

0 (0.0)

0 (0.0)

0 (0.0)

1 (0.4)

Other complications

13 (24.5)

2 (5.7)

56 (21.4)

40 (16.1)

The following complications have been removed from the table, as there are no cases reporting these conditions in the above time-periods: Myocarditis, Encephalitis, PIMS*, Acute viral myositis.

*Paediatric inflammatory multisystem syndrome.

12.2 Respiratory support

Among SARI cases who have been discharged, the highest level of respiratory support received during hospitalisation is described in Table 7.

Table 7: Number and proportion of SARI cases by highest level of respiratory support received, among discharged SARI cases, for the last four weeks (week 29 2026 to week 32 2026), and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

Respiratory support

<15y
N = 531

≥15y
N = 351

<15y
N = 2621

≥15y
N = 2481

No respiratory support given

41 (77%)

13 (37%)

166 (63%)

89 (36%)

Low-flow oxygen therapy

6 (11%)

19 (54%)

48 (18%)

107 (44%)

Non-invasive ventilation

4 (7.5%)

3 (8.6%)

40 (15%)

43 (18%)

Invasive ventilation

2 (3.8%)

0 (0%)

8 (3.1%)

6 (2.4%)

1n (%)

13 Severe outcomes

SARI cases are considered to have severe outcomes if they were admitted to ICU and/or died during their hospital stay.

Data presented in this section are based on SARI cases who have been discharged.

13.1 All age groups


Table 8: Number and proportion of SARI cases with severe outcomes, for the last four weeks (week 29 2026 to week 32 2026), and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

N = 181

N = 628

Hospital length of stay (day)

Median (IQR)

3 (2 - 5)

3 (2 - 6)

Range

1 - 15

1 - 59

Admitted to ICU, n (%)

10 (8.3%)

32 (5.9%)

Test result, among ICU cases, n (%)

SARS CoV-2

-

1 (3.1%)

Influenza

-

0 (0.0%)

RSV

-

0 (0.0%)

Coinfection

-

1 (3.1%)

Not detected*

-

30 (93.8%)

ICU length of stay (day)

Median (IQR)

3 (1 - 3)

4 (2 - 9)

Range

0 - 3

0 - 32

Died in hospital, n (%)

1 (0.6%)

12 (1.9%)

*Not detected: Influenza, SARS-CoV-2 or RSV not detected by PCR on admission to hospital.

Note: Paediatric cases from UHL may be reported as admitted to ICU, if transferred to an ICU in another paediatric hospital. However, these cases are excluded from the calculation of length of stay in ICU.


13.2 Aged <15 years


Table 9: Number and proportion of SARI cases aged <15 years with severe outcomes, for the last four weeks (week 29 2026 to week 32 2026), and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

N = 74

N = 284

Hospital length of stay (day)

Median (IQR)

2 (2 - 3)

2 (2 - 4)

Range

1 - 12

1 - 27

Admitted to ICU, n (%)

8 (13.1%)

21 (7.8%)

Test result, among ICU cases, n (%)

SARS CoV-2

-

1 (4.8%)

Influenza

-

0 (0.0%)

RSV

-

0 (0.0%)

Coinfection

-

1 (4.8%)

Not detected*

-

19 (90.5%)

ICU length of stay (day)

Median (IQR)

-

3 (1 - 4)

Range

-

0 - 17

*Not detected: Influenza, SARS-CoV-2 or RSV not detected by PCR on admission to hospital.

Note: Paediatric cases from UHL may be reported as admitted to ICU, if transferred to an ICU in another paediatric hospital. However, these cases are excluded from the calculation of length of stay in ICU.


13.3 Aged ≥15 years


Table 10: Number and proportion of SARI cases aged 15 years and older with severe outcomes, for the last four weeks (week 29 2026 to week 32 2026), and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

N = 107

N = 344

Hospital length of stay (day)

Median (IQR)

4 (3 - 5)

5 (3 - 11)

Range

1 - 15

1 - 59

Admitted to ICU, n (%)

2 (3.3%)

11 (4.0%)

Test result, among ICU cases, n (%)

SARS CoV-2

-

0 (0.0%)

Influenza

-

0 (0.0%)

RSV

-

0 (0.0%)

Coinfection

-

0 (0.0%)

Not detected*

-

11 (100.0%)

ICU length of stay (day)

Median (IQR)

-

9 (6 - 12)

Range

-

1 - 32

*Not detected: Influenza, SARS-CoV-2 or RSV not detected by PCR on admission to hospital.

13.4 Aged ≥65 years


Table 11: Number and proportion of SARI cases aged 65 years and older with severe outcomes, for the last four weeks (week 29 2026 to week 32 2026), and current season (week 21 2026 to week 32 2026)

Last four weeks

Summer season total

W29 2026-W32 2026

W21 2026-W32 2026

N = 70

N = 237

Hospital length of stay (day)

Median (IQR)

4 (3 - 6)

5 (3 - 11)

Range

1 - 15

1 - 49

Admitted to ICU, n (%)

2 (5.0%)

6 (3.2%)

Test result, among ICU cases, n (%)

SARS CoV-2

-

0 (0.0%)

Influenza

-

0 (0.0%)

RSV

-

0 (0.0%)

Coinfection

-

0 (0.0%)

Not detected*

-

6 (100.0%)

ICU length of stay (day)

Median (IQR)

-

7 (6 - 9)

Range

-

3 - 19

*Not detected: Influenza, SARS-CoV-2 or RSV not detected by PCR on admission to hospital.

14 Vaccination status

Vaccination data are available approximately one week after cases are notified to HPSC. Therefore, the vaccination status for the current week’s SARI cases has been excluded from the analysis below.

14.1 COVID-19 vaccination status

During week 21 2026 to week 31 2026 among SARI cases PCR positive for SARS-CoV-2 and aged over six months (n=6), 100.0% (n=6) had NOT received a vaccine dose in the six months prior to the reported episode of illness.

16 Appendix

Table A1: Number of SARI cases, number tested and positivity by hospital site for the current week (week 32 2026), previous two weeks (week 31 2026 and week 30 2026), and week 21 2026 to week 32 2026

Cases

SARS CoV-2 tested

SARS CoV-2 positive

Influenza & RSV tested

Influenza positive

RSV positive

Site

n

n

n (%)

n

n (%)

n (%)

W32 2026

44

41

0 (0.0)

41

0 (0.0)

0 (0.0)

SVUH

11

11

0 (0.0)

11

0 (0.0)

0 (0.0)

SJH

23

20

0 (0.0)

20

0 (0.0)

0 (0.0)

UHL

-

-

-

-

-

-

CHI-C

10

10

0 (0.0)

10

0 (0.0)

0 (0.0)

W31 2026

42

39

1 (2.6)

39

0 (0.0)

3 (7.7)

SVUH

13

13

0 (0.0)

13

0 (0.0)

0 (0.0)

SJH

11

10

0 (0.0)

10

0 (0.0)

0 (0.0)

UHL

10

9

1 (11.1)

9

0 (0.0)

2 (22.2)

CHI-C

8

7

0 (0.0)

7

0 (0.0)

1 (14.3)

W30 2026

53

48

0 (0.0)

48

2 (4.2)

2 (4.2)

SVUH

15

15

0 (0.0)

15

1 (6.7)

1 (6.7)

SJH

12

11

0 (0.0)

11

0 (0.0)

0 (0.0)

UHL

8

7

0 (0.0)

7

0 (0.0)

1 (14.3)

CHI-C

18

15

0 (0.0)

15

1 (6.7)

0 (0.0)

W21 2026-W32 2026

628

592

8 (1.4)

592

7 (1.2)

12 (2.0)

SVUH

182

181

2 (1.1)

181

2 (1.1)

2 (1.1)

SJH

162

142

0 (0.0)

142

0 (0.0)

0 (0.0)

UHL

129

123

3 (2.4)

123

3 (2.4)

5 (4.1)

CHI-C

155

146

3 (2.1)

146

2 (1.4)

5 (3.4)

17 Technical Notes

17.1 SARI Surveillance objectives

Severe acute respiratory infection (SARI) is of major relevance to public health worldwide. Surveillance of SARI is essential to monitor the (co-) circulation of respiratory pathogens and to assess disease severity. Data collected as part of SARI surveillance can provide important early warning information in the context of respiratory disease outbreaks and pandemics. SARI data can also be used as a platform to measure vaccine and antiviral effectiveness and impact. The objectives of SARI surveillance are:

  • To describe the number and incidence of SARI cases by aetiology, time, place and person

  • To describe and monitor trends, intensity of activity and severity of SARI infections

  • To identify groups at risk of severe disease

  • To detect unusual and unexpected events

  • To assess the SARI burden of disease in the participating hospital

  • To assess and monitor vaccine effectiveness

17.2 Sentinel hospital SARI surveillance sites

SARI surveillance has been implemented in four sentinel hospital sites in Ireland.

  1. St.Vincent’s University Hospital (SVUH), tertiary care adult hospital commenced 5th of July 2021 (week 27 2021)

  2. St James’s Hospital (SJH), tertiary care adult hospital commenced 30th September 2024 (week 40 2024)

  3. University Hospital Limerick (UHL), tertiary care hospital (for SARI surveillance purposes reports on paediatric cases only) commenced 30th September 2024 (week 40 2024)

  4. Children’s Health Ireland at Crumlin (CHI-C) provides quarternary and tertiary healthcare services for children nationally and secondary care for the local catchment area, commenced 29th September 2025 (week 40 2025)

SVUH and SJH report on SARI cases aged 15 years and older while UHL and CHI-C report on SARI cases aged under 15 years.

17.3 Case definition

SARI cases are identified from new admissions, based on clinical symptoms. Patients that develop SARI during their admission are not included.

Clinical SARI case:

The European Centre for Disease Prevention and Control (ECDC) clinical SARI case definition was used for SARI surveillance in Ireland since week 34 2021. The case definition was adapted in Ireland for infants aged <6 months to include increased work of breathing and apnoea as relevant symptoms. This revised definition was applied to cases admitted from week 40 2025.

SARI case definition: A person hospitalised for at least 24 hours with acute respiratory infection and symptom onset within 14 days prior to hospital admission, with at least one of the following symptoms:

  • cough

  • fever

  • shortness of breath

  • sudden onset of anosmia, ageusia or dysgeusia

  • increased work of breathing*

  • apnoea*

*for infants aged <6 months

A SARI case refers to an individual patient episode of care.

17.4 Denominator data

Weekly denominator data on all-cause hospital admissions are provided by the sentinel hospital sites. SVUH, SJH and UHL provide data on admissions via the emergency department only; CHI-C provide data on admissions via the emergency department and non-emergency department routes (e.g. transfer from other hospitals, direct admission to speciality wards), excluding day cases and elective admissions.

17.5 Laboratory testing

SARS-CoV-2, influenza, and RSV PCR testing is carried out on admission.

SARI samples that are positive for SARS-CoV-2 and have a cycle threshold (Ct) value <25 are referred for whole genome sequencing (WGS). The molecular laboratories in SVUH, SJH and UHL are spoke WGS testing sites as part of the national SARS-CoV-2 WGS surveillance programme, for further information please see Whole Genome Sequencing Programme - Health Protection Surveillance Centre (hpsc.ie). SARI WGS testing is performed on-site at SVUH, SJH, UHL and CHI-C.

Samples that are PCR positive for influenza are sent to the National Virus Reference Laboratory (NVRL) for influenza typing/subtyping/genetic and antigenic characterisation.

Samples that are PCR positive for RSV are sent to the National Virus Reference Laboratory (NVRL) for RSV typing.

17.6 Data collection and reporting

St Vincent’s University Hospital: Clinical data are collected and managed using REDCap electronic data capture tools hosted at University College Dublin. Laboratory data are extracted from APEX, the laboratory information management system (LIMS), using IBM Cognos software hosted at SVUH.

St. James’s Hospital: Clinical data are collected and managed on a specifically adapted electronic form within the patient’s electronic patient record (EPR). Laboratory data are extracted from Telepath LIMS.

University Hospital Limerick: Clinical data are collected manually on the hard copy of the UHL SARI Case Report Form (CRF) and then recorded in the electronic SARI questionnaire on ICNET. Details of laboratory results are obtained from ICNET and are also recorded in the electronic SARI questionnaire on ICNET.

Children’s Health Ireland at Crumlin: Clinical data are collected and managed using REDCap electronic data capture tools hosted by the Children’s Research Centre. Laboratory data are extracted from Winpath LIMS.

Case-based data are reported by SVUH, SJH, UHL & CHI-C to the HSE Health Protection Surveillance Centre (HPSC) on a weekly basis. Data are also reported by HPSC to ECDC via The European Surveillance System (TESSy) on weekly basis as part of the European SARI surveillance programme.

COVID-19 and influenza vaccination data are obtained from the National COVID-19 Vaccination Management System (COVAX) and linked to SARI cases by the HSE-Integrated Information Service (IIS), where data are available.

17.7 Reference dates

Respiratory virus seasons and dates

The respiratory virus surveillance season runs from week 40 (early October) to week 20 (end of May). During this time, seasonal respiratory viruses usually circulate at higher levels, compared to the summer period (weeks 21 to 39). The seasonal comparisons used in this report refer to the respiratory virus surveillance season.

04/10/2021 (Week 40 2021) – start of the 2021/2022 season

03/10/2022 (Week 40 2022) – start of the 2022/2023 season

02/10/2023 (Week 40 2023) – start of the 2023/2024 season

30/09/2024 (Week 40 2024) – start of the 2024/2025 season

29/09/2025 (Week 40 2025) – start of the 2025/2026 season

SARI surveillance

05/07/2021 (Week 27 2021) – commenced of SARI surveillance at first sentinel hospital site (SVUH)

30/09/2024 (Week 40 2024) – commenced SARI surveillance at the second and third sentinel hospital sites (SJH & UHL)

29/09/2025 (Week 40 2025) – commenced SARI surveillance at the fourth sentinel hospital site (CHI-C)

Vaccination campaign dates

27/09/2021 (Week 39 2021) – first COVID-19 booster vaccination campaign commenced

22/04/2022 (Week 16 2022) – second COVID-19 booster vaccination campaign commenced

03/10/2022 (Week 40 2022) – Autumn 2022 COVID-19 booster vaccination campaign commenced

28/04/2023 (Week 17 2023) – Spring 2023 COVID-19 booster vaccination campaign commenced

02/10/2023 (Week 40 2023) – Autumn 2023 COVID-19 booster vaccination campaign commenced

22/04/2024 (Week 17 2024) – Spring 2024 COVID-19 booster vaccination campaign commenced

30/09/2024 (Week 40 2024) – Autumn 2024 influenza & COVID-19 booster vaccination campaign commenced

03/04/2025 (Week 13 2025) – Spring 2025 COVID-19 booster vaccination campaign commenced

02/10/2025 (Week 40 2025) – Autumn 2025 influenza & COVID-19 booster vaccination campaign commenced

13/04/2026 (Week 16 2026) – Spring 2026 COVID-19 booster vaccination campaign commenced

Winter respiratory virus seasons

04/10/2021 (Week 40 2021) – start of the 2021/2022 season

03/10/2022 (Week 40 2022) – start of the 2022/2023 season

02/10/2023 (Week 40 2023) – start of the 2023/2024 season

30/09/2024 (Week 40 2024) – start of the 2024/2025 season

29/09/2025 (Week 40 2025) – start of the 2025/2026 season

Week number refers to the week of hospital admission. Weeks are from Monday to Sunday, as per the international ISO week.

The international ISO week runs from Monday to Sunday and is used as per ECDC/WHO/International reporting protocol.

17.8 Vaccination status definitions

For the purposes of SARI surveillance, vaccination status of cases is as follows:

Vaccinated COVID case: A confirmed case of COVID-19 who received any dose of a COVID-19 vaccine, ≥14 days before onset of symptoms.

Unvaccinated COVID-19 case: A confirmed case of COVID-19 who did not receive any dose of a COVID-19 vaccine i.e. was never vaccinated.

Time since vaccination: For a vaccinated COVID-19 case, this is the time between the date of last dose vaccination and the date of symptom onset and categorised as <180 days or ≥180 days since vaccination.

Vaccinated influenza case: A confirmed case of influenza will be considered as vaccinated against influenza if they received one dose of the influenza vaccine as part of the current season’s influenza vaccination campaign ≥14 days before onset of symptoms.

Unvaccinated influenza case: A confirmed case of influenza will be considered as unvaccinated if they did not receive an influenza vaccine as part of the current season’s influenza vaccination campaign or if they were vaccinated after onset of symptoms.

Vaccine status unknown: The SARI patient is reported on the SARI hospital clinical questionnaire as vaccinated, however there is no identifiable linked record of COVID-19 vaccination and/or influenza vaccination on the National Immunisation system (COVAX). Vaccination status is reported as unknown, until verified on the National Immunisation system.

18 Acknowledgements

Sincere thanks are extended to all those who participate in SARI surveillance, including those in St. Vincent’s University Hospital, St James’s Hospital, University Hospital Limerick, Children’s Health Ireland at Crumlin and the National Virus Reference Laboratory. Thanks to members of the HSE Integrated Information Services (IIS) for work on the SARI-COVAX data linkages.

This report was produced by the SARI surveillance team at HPSC, using R studio software.