Severe acute respiratory infections (SARI) surveillance report, Ireland
Weekly Report on Severe Acute Respiratory Infections (SARI), Ireland
Week 41 2026 (week ending 11/10/2026)
Report prepared on 16/10/2026
1 About this report
SARI surveillance uses the ISO week date system, in which each week runs from Monday to Sunday, see ISO Weeks Calendar.
Since week 40 2025, four sentinel hospital sites are participating in Ireland’s severe acute respiratory infections (SARI) surveillance programme. St Vincent’s University Hospital (SVUH) joined first on 5th July 2021, followed by St James’s Hospital (SJH) and University Hospital Limerick (UHL, paediatrics only) on 30th September 2024, and Children’s Health Ireland at Crumlin (CHI-C) on 29th September 2025.
The data presented in this report were extracted from the HPSC SARI surveillance database on 16/10/2026. 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.
Four of the four SARI sentinel hospital sites (100%) reported data for the current ISO week (W41 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 41 2026, SARI activity was stable and remained at low levels in Ireland; 88 SARI cases were reported from the four sentinel hospital sites. Test positivity for SARS-CoV-2, RSV, and influenza was below 10%.
3 Summary
SARI case numbers (week 41 2026):
88 SARI cases were admitted to four of the four SARI sentinel sites.
SARI cases <15 years: 49 cases from two sentinel sites.
SARI cases ≥15 years: 39 cases from two sentinel sites.
SARI incidence (week 41 2026):
The incidence rates per 100 hospital admissions* were as follows:
All SARI cases: 9.6 in week 41 2026, compared to 6.8 in week 40 2026.
SARI cases <15 years: 23.7 in week 41 2026, compared to 16.9 in week 40 2026.
SARI cases ≥15 years: 5.5 in week 41 2026, compared to 5 in week 40 2026.
*See technical notes section for further information on SARI hospital admissions data
Age profile (week 41 2026): 35.2% (n=31) cases were aged ≥65 years and 43.2% (n=38) cases aged <5 years:
All SARI cases: median age 8 years; IQR: 1-73 years.
SARI cases <15 years: median age 1 years, IQR: 0-4 years.
SARI cases ≥15 years: median age 74 years, IQR: 69-86 years.
Underlying medical conditions (week 41 2026): Overall 65.9% (n=58) of SARI cases reported at least one underlying medical condition. This included 42.9% (n=21) of cases among those aged <15 years and 94.9% (n=37) among those aged ≥15 years.
Virus test positivity among SARI cases (week 41 2026): Among those tested (96.6%, n=85):
8.2% (n=7) tested positive for SARS-CoV-2, compared to 14.5% (n=8) in week 40 2026. Among SARI cases aged <15 years and ≥15 years, 6.3% (n=3) and 10.8% (n=4) tested positive for SARS CoV-2 in week 41 2026, respectively.
5.9% (n=5) tested positive for influenza (5 A (not subtyped)), compared to 3.6% (n=2) in week 40 2026. Among SARI cases aged <15 years and ≥15 years, 4.2% (n=2) and 8.1% (n=3) tested positive for influenza in week 41 2026, respectively.
2.4% (n=2) tested positive for RSV, compared to 1.8% (n=1) in week 40 2026. Among SARI cases aged <15 years and ≥15 years, 4.2% (n=2) and 0.0% tested positive for RSV in week 41 2026, respectively.
SARS-CoV-2 genomic surveillance (week 21 2026 - week 36 2026): Of those tested (n=1110), 4.0% (n=44) were positive for SARS-CoV-2. Among SARS-CoV-2 positive specimens sequenced (n=11), XFG was the dominant variant at 63.6% (n=7), followed by BA.2.86, at 18.2% (n=2). Currently, 29 samples are awaiting sequencing, and 4 could not be sequenced.
Influenza typing/subtyping (week 21 2026 - week 41 2026): Of those tested (n=1110), 2.6% (n=29) were positive for influenza A and 0.0% were positive for influenza B. Among the influenza A samples that were subtyped, 23.5% (n=4) were A(H3) and 76.5% (n=13) were A(H1)pdm09. Currently, 12 samples are awaiting subtyping or could not be subtyped.
RSV typing (week 21 2026 - week 41 2026): Of those tested (n=1110), 1.6% (n=18) were RSV positive. Among those typed (n=16), 43.8% (n=7) were RSV A and 56.2% (n=9) RSV B. Currently, 2 samples are awaiting typing, or could not be typed.
Severe outcomes (week 21 2026 - week 41 2026):
6.1% (n=64) of SARI cases were admitted to ICU, this included 8.1% (n=41) among those aged <15 years and 4.2% (n=23) among those aged ≥15 years of age. Overall, the median length of stay was 4 days, IQR 2-6 days. Among the SARI cases admitted to ICU, 1.6% (n=1) were positive for SARS-CoV-2 only, 1.6% (n=1) for influenza only, 0.0% for RSV only and 1.6% (n=1) were positive for more than one virus.
2.7% (n=32) of SARI cases died in hospital. The median age was 82 years, IQR 71-90 years, 81.2% (n=26) were ≥65 years of age.
4 SARI case numbers and incidence rates
4.1 SARI cases by site
Figure 1. Number of SARI cases by sentinel hospital site and week of admission, week 41 2025 - week 41 2026
4.2 Incidence admissions
Figure 2. SARI age-specific incidence rates per 100 hospital admissions by week of admission, week 41 2025 - week 41 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.
4.3 Incidence (seasons)
Figure 3. SARI incidence rates per 100 hospital admissions by week of admission, between week 40 2024 and week 41 2026
Note: In the 2024/2025 season three hospital sites (SVUH, SJH & UHL) participated in SARI surveillance; four sites (SVUH, SJH, UHL & CHI-C) have participated since the beginning of season 2025/2026.
4.4 Incidence ≥15 years (seasons)
Figure 4. SARI incidence rates (age ≥15 years) per 100,000 hospital catchment population by week of admission between week 40 2024 and week 41 2026
NOTE: Estimates on hospital catchment population are only available for adult (≥15 years) hospital sites.
5 Demographics
Table 1. Number and proportion of SARI cases by sex and age, for the current week (week 41 2026), last four weeks (week 38 2026 - week 41 2026), 2026/2027 season (week 40 2026 - week 41 2026) and 2025/2026 season (week 40 2025 - week 41 2025)
Current week | Last four weeks | Current season total | Previous season total | ||
|---|---|---|---|---|---|
| W41 2026 | W38 2026-W41 2026 | W40 2026-W41 2026 | W40 2025-W41 2025 | |
Characteristic | Category | N = 88 | N = 290 | N = 143 | N = 138 |
Gender | Female | 41 (46.6) | 155 (53.4) | 68 (47.6) | 62 (44.9) |
Male | 47 (53.4) | 135 (46.6) | 75 (52.4) | 76 (55.1) | |
Age <15 years (in years) | Median (IQR) | 1 (0 - 4) | 2 (1 - 4) | 1 (0 - 4) | 1 (0 - 3) |
Range | 0 - 13 | 0 - 14 | 0 - 13 | 0 - 12 | |
Age ≥15 years (in years) | Median (IQR) | 74 (69 - 86) | 74 (62 - 82) | 75 (65 - 83) | 72 (62 - 80) |
Range | 22 - 92 | 20 - 96 | 22 - 96 | 26 - 100 | |
Age groups (years) | <1 | 13 (14.8) | 35 (12.1) | 21 (14.7) | 23 (16.7) |
1-4 | 25 (28.4) | 72 (24.8) | 32 (22.4) | 34 (24.6) | |
5-14 | 11 (12.5) | 35 (12.1) | 16 (11.2) | 11 (8.0) | |
15-44 | 2 (2.3) | 10 (3.4) | 5 (3.5) | 5 (3.6) | |
45-64 | 6 (6.8) | 33 (11.4) | 14 (9.8) | 15 (10.9) | |
65-79 | 16 (18.2) | 52 (17.9) | 27 (18.9) | 31 (22.5) | |
80+ | 15 (17.0) | 53 (18.3) | 28 (19.6) | 19 (13.8) | |
Patient residence | Residential care facility | 4 (4.5) | 21 (7.2) | 8 (5.6) | 17 (12.3) |
Private residence/home | 83 (94.3) | 263 (90.7) | 133 (93.0) | 121 (87.7) | |
Other/unknown residence | 1 (1.1) | 6 (2.1) | 2 (1.4) | 0 (0.0) | |
Note: In week 41 2026, 6.5% (n=2) of the SARI cases aged ≥65 years were resident in a residential care facility.
6 PCR testing for SARS-CoV-2, Influenza and RSV
SARI cases are tested on-admission for SARS-CoV-2, influenza and RSV using PCR at each participating hospital site.
Table 2. Number and proportion of SARI cases test positive for SARS-CoV-2, influenza and RSV, for the current week (week 41 2026), last four weeks (week 38 2026 - week 41 2026) and current season (week 40 2026 - week 41 2026)
| Current week | Last four weeks | Current season total | ||||||
|---|---|---|---|---|---|---|---|---|---|
| W41 2026 | W38 2026-W41 2026 | W40 2026-W41 2026 | ||||||
| Overall | <15y | ≥15y | Overall | <15y | ≥15y | Overall | <15y | ≥15y |
SARS-CoV-2 | 7 (8.2) | 3 (6.3) | 4 (10.8) | 25 (8.9) | 12 (8.8) | 13 (8.9) | 15 (10.7) | 7 (10.3) | 8 (11.1) |
Influenza | 5 (5.9) | 2 (4.2) | 3 (8.1) | 13 (4.6) | 3 (2.2) | 10 (6.8) | 7 (5.0) | 2 (2.9) | 5 (6.9) |
RSV | 2 (2.4) | 2 (4.2) | 0 (0.0) | 3 (1.1) | 3 (2.2) | 0 (0.0) | 3 (2.1) | 3 (4.4) | 0 (0.0) |
1n (%) | |||||||||
Note: Between week 40 2026 - week 41 2026, 0 SARI cases were coinfected with more than one of the three viruses or more than one type/subtype of the viruses under surveillance.
A further breakdown of SARI test positivity by hospital site is available in the Appendix.
6.1 Number positive
Figure 5. Number of SARI cases test positive for SARS-CoV-2, influenza and RSV by week of hospital admission, week 41 2025 - week 41 2026
6.2 Percentage positive
Figure 6. Percentage of SARI cases test positive for SARS-CoV-2, influenza, RSV and overall positivity by week of hospital admission, week 41 2025 - week 41 2026
6.3 Percentage positive by age group
Figure 7. Weekly test positivity rate of SARI cases positive for SARS-CoV-2, influenza and RSV by age group and week of hospital admission week 41 2025 - week 41 2026
7 SARS-CoV-2 genomic analysis
Note: There is typically a lag time of several weeks before sequencing is 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
Figure 8. Number of SARS CoV-2 positive SARI cases, by variant and week of hospital admission, week 41 2025 - week 41 2026
8 Influenza typing/subtyping
8.1 Influenza typing/subtyping by week
Figure 9. Number of influenza positive SARI cases by type/subtype and week of admission, week 41 2025 - week 41 2026
9 RSV typing
9.1 RSV typing by week
Figure 10. Number of RSV positive SARI cases by RSV type and week of admission, week 41 2025 - week 41 2026
Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.
10 Additional respiratory pathogen PCR testing (<15 years)
Paediatric SARI cases (<15 years) may undergo PCR testing for additional respiratory pathogens. As this extended testing is not routinely performed in adult SARI cases (≥15 years), the data presented in this section are limited to cases aged <15 years.
NOTE: Other coronavirus includes Coronavirus 229E, Coronavirus OC43, Coronavirus NL63 or Coronavirus HKU1.
10.1 PCR testing (<15 years)
Data presented for paediatric SARI cases only (aged <15 years)
Table 3. Number and proportion of PCR positive SARI cases, aged <15 years, for the current week (week 41 2026), last four weeks (week 38 2026 - week 41 2026) and current season (week 40 2026 - week 41 2026)
| Current week | Last four weeks | Current season total |
|---|---|---|---|
W41 2026 | W38 2026-W41 2026 | W40 2026-W41 2026 | |
Number tested (three main pathogens) | n=48 | n=136 | n=68 |
SARS-CoV-2 | 3 (6.2) | 12 (8.8) | 7 (10.3) |
Influenza | 2 (4.2) | 3 (2.2) | 2 (2.9) |
RSV | 2 (4.2) | 3 (2.2) | 3 (4.4) |
Number tested (additional pathogens) | n=40 | n=124 | n=60 |
Rhino/entero virus | 24 (60.0) | 82 (66.1) | 37 (61.7) |
Adenovirus | 4 (10.0) | 7 (5.6) | 5 (8.3) |
Parainfluenza 1 | 4 (10.0) | 8 (6.5) | 5 (8.3) |
Parainfluenza 2 | 1 (2.5) | 6 (4.8) | 1 (1.7) |
Parainfluenza 3 | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Parainfluenza 4 | 0 (0.0) | 1 (0.8) | 1 (1.7) |
Human metapneumovirus | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Mycoplasma pneumonia | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Chlamydia pneumonia | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Other coronavirus | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Number tested (Bocavirus only) | n=25 | n=93 | n=45 |
Bocavirus | 0 (0.0) | 3 (3.2) | 2 (4.4) |
NOTE: Bocavirus is only tested in CHI-C, therefore the denominator used to calculate the Bocavirus percentage is the number tested in CHI-C, for all other pathogens shown, the denominator used is the number tested in both UHL & CHI-C
10.2 Heatmap
Figure 11. Percent of SARI cases, aged <15 years, positive for SARS-CoV-2, influenza, RSV and additional respiratory tests, week 21 2026 - week 41 2026
NOTE: Bocavirus is only tested in CHI-C, therefore the denominator used to calculate the Bocavirus percentage is the number tested in CHI-C, for all other pathogens shown, the denominator used is the number tested in both UHL & CHI-C
10.3 Number positive
Figure 12. Number of SARI cases, aged <15 years, positive for additional respiratory tests and number of SARI cases, week 21 2026 - week 41 2026
NOTE: Bocavirus is only tested in CHI-C, all other viruses are tested in both CHI-C and UHL
10.4 Percent positive
Figure 13. Percent of SARI cases, aged <15 years, positive for SARS-CoV-2, influenza, RSV and additional respiratory tests, week 21 2026 - week 41 2026
NOTE: Bocavirus is only tested in CHI-C, therefore the denominator used to calculate the percentage is the number tested in CHI-C, for all other pathogens shown, the denominator used is the number tested in both UHL & CHI-C
11 Symptoms
Number and proportion of SARI cases’ clinical symptoms, either at or prior to hospital admission, for the last four weeks (week 38 2026 - week 41 2026) and current season (week 40 2026 - week 41 2026)
12 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 4. Number and proportion of SARI cases with underlying medical conditions reported on hospital admission, for the last four weeks (week 38 2026 - week 41 2026) and current season (week 40 2026 - week 41 2026)
| Last four weeks | Current season total | ||
|---|---|---|---|---|
| W38 2026-W41 2026 | W40 2026-W41 2026 | ||
Condition | <15y | ≥15y | <15y | ≥15y |
Number of underlying medical conditions | ||||
None | 86 (60.6) | 6 (4.1) | 42 (60.9) | 2 (2.7) |
One | 45 (31.7) | 27 (18.2) | 20 (29.0) | 14 (18.9) |
Two | 7 (4.9) | 45 (30.4) | 5 (7.2) | 19 (25.7) |
Three or more | 4 (2.8) | 70 (47.3) | 2 (2.9) | 39 (52.7) |
Conditions reported | ||||
Lung disease | 7 (4.9) | 77 (52.0) | 5 (7.2) | 38 (51.4) |
Heart disease | 10 (7.0) | 63 (42.6) | 5 (7.2) | 30 (40.5) |
Hypertension | 0 (0.0) | 54 (36.5) | 0 (0.0) | 32 (43.2) |
Cancer | 2 (1.4) | 40 (27.0) | 1 (1.4) | 21 (28.4) |
Rheumatological disease | 0 (0.0) | 35 (23.6) | 0 (0.0) | 20 (27.0) |
Asthma | 18 (12.7) | 13 (8.8) | 5 (7.2) | 9 (12.2) |
Neurological disease | 8 (5.6) | 22 (14.9) | 7 (10.1) | 10 (13.5) |
Diabetes | 0 (0.0) | 23 (15.5) | 0 (0.0) | 14 (18.9) |
Immunocompromised | 2 (1.4) | 21 (14.2) | 0 (0.0) | 7 (9.5) |
Kidney disease | 1 (0.7) | 12 (8.1) | 1 (1.4) | 5 (6.8) |
Prematurity* | 12 (8.5) | 0 (0.0) | 5 (7.2) | 0 (0.0) |
Dementia | 0 (0.0) | 11 (7.4) | 0 (0.0) | 4 (5.4) |
Intellectual disability | 9 (6.3) | 1 (0.7) | 5 (7.2) | 0 (0.0) |
Liver disease | 0 (0.0) | 6 (4.1) | 0 (0.0) | 3 (4.1) |
Obesity | 0 (0.0) | 2 (1.4) | 0 (0.0) | 1 (1.4) |
Down syndrome | 2 (1.4) | 0 (0.0) | 2 (2.9) | 0 (0.0) |
Cystic fibrosis | 0 (0.0) | 1 (0.7) | 0 (0.0) | 1 (1.4) |
The following conditions have been removed from the table, as there are no cases reporting these conditions in the above time-periods: Asplenia, Long COVID, Tuberculosis.
*Prematurity: birth before 37 weeks gestation, this applies to paediatric cases under 2 years of age only.
13 Clinical course
13.1 Complications
Information on patients’ clinical course during hospitalisation is only available after discharge. These data are mostly collected manually, therefore, there may be a delay between patient discharge and data collection. Data collection is ongoing for those not yet discharged from hospital.
SARI cases may have one or more reported complications. Among cases with discharge information available, pneumonia was the most commonly reported complication.
Table 5. Number and proportion of complications among discharged SARI cases, for the last four weeks (week 38 2026 - week 41 2026) and current season (week 40 2026 - week 41 2026)
| Last four weeks | Current season total | ||
|---|---|---|---|---|
| W38 2026-W41 2026 | W40 2026-W41 2026 | ||
Complication | <15y | ≥15y | <15y | ≥15y |
No complications | 36 (40.4) | 3 (15.0) | 13 (36.1) | 0 (0.0) |
Pneumonia | 25 (28.1) | 15 (75.0) | 10 (27.8) | 0 (0.0) |
Bronchiolitis | 18 (20.2) | 0 (0.0) | 10 (27.8) | 0 (0.0) |
ARDS | 1 (1.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Sepsis | 0 (0.0) | 1 (5.0) | 0 (0.0) | 0 (0.0) |
Multi organ failure | 0 (0.0) | 1 (5.0) | 0 (0.0) | 0 (0.0) |
Acute kidney injury | 0 (0.0) | 1 (5.0) | 0 (0.0) | 0 (0.0) |
Heart failure | 0 (0.0) | 1 (5.0) | 0 (0.0) | 0 (0.0) |
Respiratory complications | 0 (0.0) | 1 (5.0) | 0 (0.0) | 0 (0.0) |
Other complications | 20 (22.5) | 2 (10.0) | 8 (22.2) | 0 (0.0) |
The following complications have been removed from the table, as there are no cases reporting these conditions in the above time-periods: Myocarditis, Encephalitis, Secondary bacterial infections, PIMS*, Acute atrial fibrillation, Acute viral myositis.
*Paediatric inflammatory multisystem syndrome.
13.2 Respiratory support
Among SARI cases who have been discharged, the highest level of respiratory support received during hospitalisation is described below.
Table 6. Number and proportion of SARI cases by highest level of respiratory support received, among discharged SARI cases, for the last four weeks (week 38 2026 - week 41 2026) and current season (week 40 2026 - week 41 2026)
Last four weeks | Current season total | |||
|---|---|---|---|---|
| W38 2026-W41 2026 | W40 2026-W41 2026 | ||
Respiratory support | <15y | ≥15y | <15y | ≥15y |
No respiratory support given | 8 (42.1) | 47 (52.8) | 21 (58.3) | 0 (0.0) |
Low-flow oxygen therapy | 6 (31.6) | 26 (29.2) | 10 (27.8) | 0 (0.0) |
Non-invasive ventilation | 5 (26.3) | 15 (16.9) | 5 (13.9) | 0 (0.0) |
Invasive ventilation | 0 (0.0) | 1 (1.1) | 0 (0.0) | 0 (0.0) |
1n (%) | ||||
14 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.
14.1 All age groups
Table 7. Number and proportion of SARI cases with severe outcomes, for the last four weeks (week 38 2026 - week 41 2026), current season (week 40 2026 - week 41 2026) and previous season (week 40 2025 - week 41 2025)
Last four weeks | Current season total | Previous season total | |
|---|---|---|---|
| W38 2026-W41 2026 | W40 2026-W41 2026 | W40 2025-W41 2025 |
| N = 290 | N = 143 | N = 138 |
Hospital length of stay (day) | |||
Median (IQR) | 2 (1 - 5) | 2 (1 - 4) | 4 (2 - 7) |
Range | 1 - 15 | 1 - 12 | 1 - 60 |
Admitted to ICU, n (%) | 17 (8.8%) | 6 (7.3) | 9 (6.5%) |
Test result, among ICU cases, n (%) | |||
SARS CoV-2 | - | - | 1 (11.1%) |
Influenza | - | - | 0 (0.0%) |
RSV | - | - | 0 (0.0%) |
Coinfection | - | - | 0 (0.0%) |
Not detected* | - | - | 8 (88.9%) |
ICU length of stay (day) | |||
Median (IQR) | 2 (1 - 3) | 2 (1 - 2) | 1 (0 - 1) |
Range | 1 - 4 | 1 - 2 | 0 - 10 |
Died in hospital, n (%) | 1 (0.3%) | 0 (0.0) | 3 (2.2%) |
*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.
14.2 Aged <15 years
Severe outcomes by age category for the current season are not currently presented, pending receipt of additional discharge data.
14.3 Aged ≥15 years
Severe outcomes by age category for the current season are not currently presented, pending receipt of additional discharge data
14.4 Aged ≥65 years
Severe outcomes by age category for the current season are not currently presented, pending receipt of additional discharge data
15 Vaccination status
Vaccination status of SARS-CoV-2 and influenza positive SARI cases will be presented once a sufficient number of vaccinated cases are reported for the current 2026/2027 season.
16 Links to other national respiratory virus reports
Respiratory viruses
COVID-19
17 Appendix
17.1 Table
Table 8. Number of SARI cases number tested and positivity by hospital site, for the current week, previous two weeks and current season (week 40 2026 - week 41 2026)
Cases | SARS CoV-2 tested | SARS CoV-2 positive | Influenza & RSV tested | Influenza positive | RSV positive | |
|---|---|---|---|---|---|---|
Site | n | n | n (%) | n | n (%) | n (%) |
W41 2026 | 88 | 85 | 7 (8.2) | 85 | 5 (5.9) | 2 (2.4) |
SVUH | 21 | 21 | 3 (14.3) | 21 | 2 (9.5) | 0 (0.0) |
SJH | 18 | 16 | 1 (6.3) | 16 | 1 (6.3) | 0 (0.0) |
UHL | 19 | 18 | 0 (0.0) | 18 | 1 (5.6) | 0 (0.0) |
CHI-C | 30 | 30 | 3 (10.0) | 30 | 1 (3.3) | 2 (6.7) |
W40 2026 | 55 | 55 | 8 (14.5) | 55 | 2 (3.6) | 1 (1.8) |
SVUH | 15 | 15 | 1 (6.7) | 15 | 1 (6.7) | 0 (0.0) |
SJH | 20 | 20 | 3 (15.0) | 20 | 1 (5.0) | 0 (0.0) |
UHL | - | - | - | - | - | - |
CHI-C | 20 | 20 | 4 (20.0) | 20 | 0 (0.0) | 1 (5.0) |
W39 2026 | 88 | 85 | 5 (5.9) | 85 | 5 (5.9) | 0 (0.0) |
SVUH | 17 | 17 | 2 (11.8) | 17 | 3 (17.6) | 0 (0.0) |
SJH | 23 | 23 | 1 (4.3) | 23 | 2 (8.7) | 0 (0.0) |
UHL | 23 | 20 | 2 (10.0) | 20 | 0 (0.0) | 0 (0.0) |
CHI-C | 25 | 25 | 0 (0.0) | 25 | 0 (0.0) | 0 (0.0) |
W40 2026-W41 2026 | 143 | 140 | 15 (10.7) | 140 | 7 (5.0) | 3 (2.1) |
SVUH | 36 | 36 | 4 (11.1) | 36 | 3 (8.3) | 0 (0.0) |
SJH | 38 | 36 | 4 (11.1) | 36 | 2 (5.6) | 0 (0.0) |
UHL | 19 | 18 | 0 (0.0) | 18 | 1 (5.6) | 0 (0.0) |
CHI-C | 50 | 50 | 7 (14.0) | 50 | 1 (2.0) | 3 (6.0) |
18 Technical Notes
18.1 SARI Surveillance objectives
Severe acute respiratory infection (SARI) is of major relevance to public health worldwide. SARI surveillance is essential to monitor the (co-) circulation of respiratory pathogens and to assess disease severity. It can provide early warning of respiratory disease outbreaks and pandemics and can also support the evaluation of 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
18.2 Sentinel hospital SARI surveillance sites
SARI surveillance has been implemented at four sentinel hospital sites in Ireland.
St.Vincent’s University Hospital (SVUH), a tertiary care adult hospital, commenced SARI surveillance on 5th of July 2021 (week 27 2021)
St James’s Hospital (SJH), a tertiary care adult hospital commenced SARI surveillance on 30th September 2024 (week 40 2024)
University Hospital Limerick (UHL), a tertiary care hospital (for SARI surveillance purposes reports on paediatric cases only) commenced SARI surveillance on 30th September 2024 (week 40 2024)
Children’s Health Ireland at Crumlin (CHI-C) which provides national quaternary and tertiary paediatric healthcare services and secondary care for it’s local catchment area, commenced SARI surveillance on 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.
18.3 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.
18.4 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.
Denominator data for the hospital catchment area are based on the Census of Population, 2022. The hospital catchment data were prepared and provided by the Health Intelligence Unit (HIU) of the Health Service Executive (HSE). These data are available for adult (≥15y) SARI sites only (SVUH & SJH).
18.5 Laboratory testing
SARS-CoV-2, influenza, and RSV PCR testing is carried out on admission in all SARI sentinel hospital sites.
At paediatric (<15y) SARI sentinel sites, additional testing using an extended respiratory panel is carried out on admission for patients aged under 15 years.
SARI samples that are PCR positive for SARS-CoV-2 and have a cycle threshold (Ct) value <25 are referred for whole genome sequencing (WGS). SARS-CoV-2 sequencing testing is performed on-site at SVUH, and CHI-C, while the National Virus Reference Laboratory (NVRL) performs the sequencing of SARS-CoV-2 positive samples from SJH and UHL.
Samples that are PCR positive for influenza are referred to the NVRL for influenza typing/subtyping/genetic and antigenic characterisation.
Samples that are PCR positive for RSV are sent to the NVRL for RSV typing.
18.6 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 (EpiPulse cases) on weekly basis as part of the European integrated respiratory virus surveillance programme.
COVID-19 and influenza vaccination data are obtained from the National Immunisation Information System (NIIS) and linked to SARI cases by the HSE-Integrated Information Service (IIS), where data are available.
18.7 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.
30/09/2024 (Week 40 2024) – start of the 2024/2025 season
29/09/2025 (Week 40 2025) – start of the 2025/2026 season
28/09/2026 (Week 40 2026) – start of the 2026/2027 season
SARI surveillance implementation dates
05/07/2021 (Week 27 2021) – SARI surveillance commenced at first sentinel hospital site (SVUH)
30/09/2024 (Week 40 2024) – SARI surveillance commenced at the second and third sentinel hospital sites (SJH & UHL)
29/09/2025 (Week 40 2025) – SARI surveillance commenced at the fourth sentinel hospital site (CHI-C)
Vaccination campaign dates
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
08/10/2026 (Week 41 2026) - Autumn 2026 influenza & COVID-19 booster vaccination campaign commenced
18.8 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 a dose of COVID-19 vaccine as part of the current season’s COVID-19 vaccination campaign at least 14 days before onset of symptoms.
Unvaccinated COVID-19 case: A confirmed case of COVID-19 who did not receive a dose of COVID-19 vaccine as part of the current season’s COVID-19 vaccination campaign or if they were vaccinated after onset of symptoms.
Vaccinated influenza case: A confirmed case of influenza who received a dose of the influenza vaccine as part of the current season’s influenza vaccination campaign at least ≥14 days before onset of symptoms.
Unvaccinated influenza case: A confirmed case of influenza who 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 Information System (NIIS). Vaccination status is reported as unknown, until verified on NIIS.
19 Acknowledgements
Sincere thanks are extended to all those who participate in SARI surveillance in Ireland, 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-NIIS data linkages.
This report was produced by the SARI team, Sentinel and Syndromic Unit (SSU), HPSC, using R studio software.