Severe acute respiratory infections (SARI) surveillance report, Ireland
Weekly Report on Severe Acute Respiratory Infections (SARI), Ireland
Week 16 2026 (week ending 19/04/2026)
Report prepared on 22/04/2026
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 22/04/2026. 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 (W16 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 16 2026, SARI activity remained stable and at low levels in Ireland; 41 SARI cases were reported from three of the four sentinel hospital sites. Test positivity for SARS-CoV-2 and RSV was below 10%, and there were no cases positive for influenza.
3 Summary
Note: Data presented below relate to ISO week
SARI case numbers (week 16 2026):
41 SARI cases were admitted to three of the four SARI sentinel sites.
SARI cases <15 years: 8 cases from one sentinel site.
SARI cases ≥15 years: 33 cases from two sentinel sites.
SARI incidence:
The incidence rates per 1,000 hospital admissions* were as follows:
All SARI cases: 50.9 in week 16 2026, compared to 88.7 in week 15 2026.
SARI cases <15 years: 63.5 in week 16 2026, compared to 216.1 in week 15 2026.
SARI cases ≥15 years: 48.5 in week 16 2026, compared to 49.5 in week 15 2026 (2.0% decrease).
*See technical notes section for further information on SARI hospital admissions data
Age profile (week 16 2026): 51.2% (n=21) cases were aged ≥65 years and 19.5% (n=8) cases aged <5 years:
All SARI cases: median age 65 years; IQR: 51-80 years.
SARI cases <15 years: median age 1 years, IQR: 0-1 years.
SARI cases ≥15 years: median age 72 years, IQR: 63-80 years.
Virus test positivity among SARI cases (week 16 2026): Among those tested (90.2%, n=37):
2.7% (n=1) tested positive for SARS-CoV-2, compared to 0.0% in week 15 2026. Among SARI cases aged <15 years and ≥15 years, 0.0% and 3.3% (n=1) tested positive for SARS CoV-2 in week 16 2026, respectively.
No cases tested positive for influenza.
5.4% (n=2) tested positive for RSV, compared to 5.6% (n=4) in week 15 2026. Among SARI cases aged <15 years and ≥15 years, 28.6% (n=2) and 0.0% tested positive for RSV in week 16 2026, respectively.
Genomic surveillance (week 40 2025 to week 12 2026): Among SARI SARS-CoV-2 positive specimens sequenced (n=41), XFG was the dominant variant at 51.2% (n=21), followed by BA.3.2, at 24.4% (n=10). Variant BA.3.2 was identified in 24.4% (n=10) of specimens sequenced.
Influenza typing/subtyping (week 40 2025 to week 16 2026): Of those tested, 19.2% (n=567) were positive for influenza A which was the predominant virus among influenza positive SARI admissions, and 0.1% (n=4) were positive for influenza B. Among the influenza A samples that were subtyped, 89.1% (n=433) were A(H3) and 10.5% (n=51) were A(H1)pdm09. Currently 83 samples are awaiting subtyping or could not be subtyped.
RSV typing/subtyping (week 40 2025 to week 16 2026): Since week 40 2025, RSV A was co-circulating with RSV B among RSV positive SARI admissions. Among those subtyped (n=353), 57.5% (n=203) were RSV A and 42.5% (n=150) RSV B. Currently, 38 samples are awaiting subtyping, or could not be subtyped.
Underlying medical conditions (week 16 2026): Overall 87.8% (n=36) of SARI cases reported at least one underlying medical condition. This included 37.5% (n=3) of cases among those aged <15 years and 100% (n=33) among those aged ≥15 years.
Severe outcomes (week 40 2025 to week 16 2026):
5.4% (n=150) of SARI cases were admitted to ICU, this included 6.9% (n=102) among those aged <15 years and 3.8% (n=48) among those aged ≥15 years of age. Overall, the median length of stay was 3 days, IQR 1-4 days. Among the SARI cases admitted to ICU, 4.0% (n=6) were positive for SARS-CoV-2 only, 9.3% (n=14) for influenza only, 16.7% (n=25) for RSV only and 1.3% (n=2) were positive for more than one virus.
2.8% (n=82) of SARI cases died in hospital. The median age was 81 years, IQR 74 -87 years, 90.2% (n=74) were ≥65 years of age.
Vaccination status (week 40 2025 to week 15 2026): These data are reported with a one-week time lag.
Amongst SARI cases positive for SARS-CoV-2 (n=59), 84.7% (n=50) had NOT received a COVID-19 vaccine dose in the six months prior to the reported episode of illness.
Amongst SARI cases positive for influenza (n=503), 67.6% (n=340) had NOT received the 2025/2026 influenza season vaccine 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 week 40 2024 to week 16 2026
Note: CHI-C included from week 40 2025, while only three hospital sites (SVUH, SJH & UHL) participated during the 2024/2025 season.