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
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Key messages
During week 4 2025, influenza activity in Ireland remained at high
levels, although notified influenza cases, hospitalisations and hospital
bed occupancy have decreased during the last three weeks. Sentinel GP
influenza positivity declined during the last four weeks, but remained
above the 10% positivity threshold at 39.2%. Influenza A(H1)pdm09 is the
predominant influenza virus circulating, with influenza A(H3) and B
virus detections reported at lower levels. RSV notifications and
hospitalisations decreased for the third consecutive week in week 4
2025. COVID-19 activity remained at low levels during week 4 2025.
Summary for week 4
2025
Primary Care Surveillance
The sentinel GP Acute Respiratory Infection (ARI) consultation rate
decreased in week 4 2025, for the third consecutive week, to
98.6/100,000 population. The highest rates were in those aged <5
years at 319.7/100,000 population in week 4. Sentinel GP influenza
positivity declined for the fourth week in a row, to 39.2%, but remained
above the 10% positivity threshold levels. Sentinel GP RSV positivity
was below the baseline threshold. All other seasonal respiratory
pathogens are circulating at lower levels and are below baseline. The
proportion of GP-OOH calls for self-reported cough decreased in week 4
but was still above threshold levels for almost all age groups except
those aged 65 and over. The proportion of self-reported flu calls also
decreased in all age-groups and was below or at baseline in all age
groups except for those aged 15-64 years.
COVID-19
COVID-19 activity remained at low levels across all indicators in
week 4 2025, with a decrease in case numbers and hospitalisations
compared to week 3. COVID-19 cases decreased by 11.0%, from 146 cases
notified in week 3 to 130 cases in week 4. Hospitalised cases decreased
by 10.0%, from 50 cases in week 3 to 45 cases in week 4. ICU admissions
and deaths remained low. XEC was the dominant SARS-CoV-2 variant and
accounted for 73.6% of samples sequenced between week 50 2024 and week
02 2025. Due to technical difficulties, up-to-date wastewater graphs are
not available. However, SARS-CoV-2 levels in wastewater remain low.
Influenza
Influenza activity decreased in week 4 2025, for the third
consecutive week. The number of notified influenza cases decreased by
42% to 1,456 cases in week 4 2025, compared to 2,520 reported in in week
3 2025.The overall notification rate was 28.3/100,000 population and was
highest in those aged ≥80 years at 119.3/100,000 population, followed by
those aged less than one year at 69.2/100,000 population. There were 268
hospitalisations, one ICU admission and two deaths notified during week
4 2025. For the season to date (weeks 40 2024 to week 4 2025), 169 ICU
admissions and 122 deaths have been reported. Influenza hospital bed
occupancy decreased during week 4 2025. Influenza A(H1)pdm09 is the
predominant virus circulating this season, followed by influenza B and
influenza A(H3). Influenza B notified cases remain at low levels. Among
all notified influenza cases during week 4 2025, 22.7% (331) were
influenza B.
RSV
The number of notified RSV cases decreased by 37% in week 4 2025,
with 377 cases notified compared to 594 in week 3 2025. The overall
notification rate decreased for the third consecutive week to
7.3/100,000 population. In week 4 2025, the notification rate was
highest in those aged less than one year at 77.9/100,000 population,
followed by those aged 80 years and over at 50.3/100,000 population.
There were 106 hospitalisations and one ICU admission reported in week 4
2025. For the season to date (weeks 40 2024 to week 4 2025), 65 ICU
admissions and four deaths have been reported.
Severe Acute Respiratory Infection (SARI)
Based on data from the three sentinel hospital sites, the number of
SARI cases reported in week 4 decreased by 19.5% with 70 cases, compared
to 87 cases reported in week 3 2025. In week 4 2025, SARS-CoV-2
positivity remained at low levels increasing to 2.9% from 2.3% in week
3; influenza positivity decreased to 34.3% from 37.9% in week 3 and RSV
positivity increased to 18.6% from 14.9% in week 3.
Outbreaks
The overall number of respiratory virus outbreaks have decreased
during week 4. A total of seven COVID-19 outbreaks (three in hospitals,
two in nursing homes and two in residential institutions) were reported
during week 4, an increase from five outbreaks notified during week 3.
Eighteen influenza outbreaks (five in hospitals, five in nursing homes,
seven in residential institutions and one in another healthcare setting)
were reported in week 4, a decrease from 46 outbreaks in week 3. Nine
RSV outbreaks (one in a hospital, five in nursing homes and three in
residential institutions) and eight other ARI outbreaks (seven in
nursing homes and one in a community hospital/long-stay unit) were also
notified during week 4 2025. There was also one mixed ARI outbreak
consisting of multiple respiratory pathogens notified during week 4.
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.
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.
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, with at least one of the following
symptoms: cough, fever, shortness of breath OR sudden onset of anosmia,
ageusia or dysgeusia with onset of symptoms within 14 days prior to
hospital admission. 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) and where
COVID-19, influenza or RSV is reported in any of the four cause of death
fields on the death certificate. Deaths where there is a clear
alternative cause of death (e.g. trauma, suicide) are not recorded as
COVID-19/influenza/RSV deaths. Deaths where there is a period of
complete recovery (as assessed by a clinician) between a COVID-19,
influenza or RSV episode of illness and death, are also not recorded as
deaths.
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 from new admissions through the Emergency
Department, based on clinical symptoms. Patients that develop SARI
during their admission, or who are admitted through alternate routes,
are not included.
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.
As of 14/10/2024 HPSC has ceased reporting on detections of hMPV from
virological surveillance of sentinel and non-sentinel specimens. This is
due to an increased risk of false positive results from the routine
respiratory panel.
National SARS-CoV-2 Whole Genome Sequencing Surveillance Programme
(NSWGSSP): The SARS-CoV-2 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 2023 (specimen dates between
01/10/2023 and 11/01/2025). The SARS-CoV-2 sequencing results included
in this report reflect all data available as of 27/01/2025.
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 reports available here
Appendix
Appendix Table 1: Notified
laboratory confirmed cases of COVID-19, influenza and RSV by age, sex
and HSE health region, from week 40 2024, to week 4 2025. Data source:
CIDR.
Number of cases (incidence per 100,000 population) |
|---|
| All pathogens | COVID-19 | Influenza | RSV |
|---|
Cases | 27,705 (538.1) | 3,544 (68.8) | 18,618 (361.6) | 5,543 (107.6) |
Age groups (years) |
|
|
|
|
<1 | 2,113 (3,656.0) | 164 (283.8) | 590 (1,020.8) | 1,359 (2,351.4) |
1-4 | 4,156 (1,749.0) | 95 (40.0) | 2,247 (945.6) | 1,814 (763.4) |
5-14 | 2,199 (306.7) | 51 (7.1) | 1,901 (265.2) | 247 (34.5) |
15-44 | 4,917 (237.9) | 494 (23.9) | 4,077 (197.2) | 346 (16.7) |
45-64 | 4,614 (356.8) | 621 (48.0) | 3,561 (275.3) | 432 (33.4) |
65-79 | 5,018 (843.0) | 962 (161.6) | 3,388 (569.1) | 668 (112.2) |
>80 | 4,684 (2,587.5) | 1,156 (638.6) | 2,851 (1,574.9) | 677 (374.0) |
Median age (IQR) | 47 (6-74) | 72 (48-83) | 47 (14-72) | 3 (1-63) |
Sex |
|
|
|
|
Male | 13,165 (517.4) | 1,682 (66.1) | 8,761 (344.3) | 2,722 (107.0) |
Female | 14,488 (556.2) | 1,861 (71.5) | 9,818 (376.9) | 2,809 (107.8) |
HSE Health Regions |
|
|
|
|
Dublin and North East | 6,597 (128.1) | 808 (68.1) | 4463 (376) | 1326 (111.7) |
Dublin and Midlands | 4,932 (95.8) | 621 (57.6) | 3244 (301) | 1067 (99) |
Dublin and South East | 6,209 (120.6) | 863 (88.9) | 4307 (443.5) | 1039 (107) |
South West | 3,608 (70.1) | 489 (66) | 2533 (342) | 586 (79.1) |
Mid West | 2,007 (39) | 310 (75) | 1438 (348.1) | 259 (62.7) |
West and North West | 4,348 (84.4) | 453 (59.6) | 2629 (346.1) | 1266 (166.7) |
Appendix Table 2:
Hospitalised laboratory confirmed cases of COVID-19, influenza and RSV
by age, sex and HSE health region from week 40 2024 to week 4 2025. Data
source: CIDR.
Number of cases (incidence per 100,000 population) |
|---|
| All pathogens | COVID-19 | Influenza | RSV |
|---|
Cases | 7,713 (149.8) | 1,416 (27.5) | 4,457 (86.6) | 1,840 (35.7) |
Age groups (years) |
|
|
|
|
<1 | 748 (1,294.2) | 62 (107.3) | 183 (316.6) | 503 (870.3) |
1-4 | 1,293 (544.1) | 36 (15.2) | 612 (257.6) | 645 (271.4) |
5-14 | 620 (86.5) | 29 (4.0) | 491 (68.5) | 100 (13.9) |
15-44 | 711 (34.4) | 119 (5.8) | 513 (24.8) | 79 (3.8) |
45-64 | 1,044 (80.7) | 220 (17.0) | 716 (55.4) | 108 (8.4) |
65-79 | 1,603 (269.3) | 411 (69.0) | 989 (166.1) | 203 (34.1) |
>80 | 1,693 (935.2) | 539 (297.7) | 952 (525.9) | 202 (111.6) |
Median age (IQR) | 56 (4-78) | 75 (58-84) | 58 (9-78) | 2 (0-57) |
Sex |
|
|
|
|
Male | 3,833 (150.6) | 727 (28.6) | 2,183 (85.8) | 923 (36.3) |
Female | 3,875 (148.8) | 689 (26.5) | 2,270 (87.2) | 916 (35.2) |
HSE Health Regions |
|
|
|
|
Dublin and North East | 944 (18.3) | 182 (15.3) | 533 (44.9) | 229 (19.3) |
Dublin and Midlands | 1,236 (24) | 274 (25.4) | 599 (55.6) | 363 (33.7) |
Dublin and South East | 1,679 (32.6) | 274 (28.2) | 975 (100.4) | 430 (44.3) |
South West | 1,189 (23.1) | 244 (32.9) | 744 (100.5) | 201 (27.1) |
Mid West | 972 (18.9) | 172 (41.6) | 648 (156.9) | 152 (36.8) |
West and North West | 1,693 (32.9) | 270 (35.5) | 958 (126.1) | 465 (61.2) |
Appendix Table 3: Number
and percentage positive Sentinel GP ARI specimens by respiratory virus
for week 3 2025, week 4 2025 and the 2024/2025 season. Data source:
NVRL.
| Week 3 2025 (N = 173) | Week 4 2025 (N = 51) | 2024/2025 (N = 2611) |
|---|
Virus | Total positive | % positive | Total positive | % positive | Total positive | % positive |
|---|
SARS-CoV-2 | 4 | 2.3 | 0 | 0.0 | 75 | 2.9 |
Influenza Virus | 74 | 42.8 | 20 | 39.2 | 759 | 29.1 |
Respiratory Syncytial Virus (RSV) | 12 | 6.9 | 3 | 5.9 | 131 | 5.0 |
Rhino/enterovirus | 10 | 5.8 | 4 | 7.8 | 422 | 16.2 |
Adenovirus | 0 | 0.0 | 0 | 0.0 | 12 | 0.5 |
Bocavirus | 2 | 1.2 | 0 | 0.0 | 9 | 0.3 |
Parainfluenza virus type 1 (PIV-1) | 0 | 0.0 | 0 | 0.0 | 36 | 1.4 |
Parainfluenza virus type 2 (PIV-2) | 0 | 0.0 | 0 | 0.0 | 35 | 1.3 |
Parainfluenza virus type 3 (PIV-3) | 0 | 0.0 | 0 | 0.0 | 10 | 0.4 |
Parainfluenza virus type 4 (PIV-4) | 0 | 0.0 | 0 | 0.0 | 27 | 1.0 |
Appendix Table 4: Number
and percentage positive NVRL non-sentinel respiratory specimens by
respiratory virus, week 3 2025, week 4 2025 and the 2024/2025 season.
Data source: NVRL.
| Week 3 2025 (N = 491) | Week 4 2025 (N = 242) | 2024/2025 (N = 6058) |
|---|
Virus | Total positive | % positive | Total positive | % positive | Total positive | % positive |
|---|
SARS-CoV-2 | 12 | 2.4 | 2 | 0.8 | 144 | 2.4 |
Influenza Virus | 124 | 25.3 | 35 | 14.5 | 1,750 | 28.9 |
Respiratory Syncytial Virus (RSV) | 47 | 9.6 | 24 | 9.9 | 494 | 8.2 |
Rhino/enterovirus | 35 | 7.1 | 15 | 6.2 | 602 | 9.9 |
Adenovirus | 2 | 0.4 | 2 | 0.8 | 38 | 0.6 |
Bocavirus | 3 | 0.6 | 0 | 0.0 | 37 | 0.6 |
Parainfluenza virus type 1 (PIV-1) | 2 | 0.4 | 0 | 0.0 | 51 | 0.8 |
Parainfluenza virus type 2 (PIV-2) | 1 | 0.2 | 4 | 1.7 | 45 | 0.7 |
Parainfluenza virus type 3 (PIV-3) | 1 | 0.2 | 0 | 0.0 | 9 | 0.1 |
Parainfluenza virus type 4 (PIV-4) | 0 | 0.0 | 0 | 0.0 | 45 | 0.7 |
Appendix Table 5:
Influenza type and sub-type distribution among sentinel GP ARI and
non-sentinel respiratory influenza positive specimens for week 3 2025,
week 4 2025 and the 2024/2025 season. Data source: NVRL.
| | | Influenza A | Influenza B |
|---|
Time period | Specimen source | Total influenza positive | Total | A(H1)pdm09 | A(H3) | A(not subtyped) | Total | B Victoria | B (upspecified) |
|---|
Week 3 2025 | Sentinel GP ARI | 74 | 51 | 36 | 11 | 4 | 23 | 0 | 23 |
Non-sentinel respiratory | 124 | 101 | 77 | 13 | 11 | 23 | 0 | 23 |
Total | 198 | 152 | 113 | 24 | 15 | 46 | 0 | 46 |
Week 4 2025 | Sentinel GP ARI | 20 | 11 | 11 | 0 | 0 | 9 | 0 | 9 |
Non-sentinel respiratory | 35 | 29 | 18 | 9 | 2 | 6 | 0 | 6 |
Total | 55 | 40 | 29 | 9 | 2 | 15 | 0 | 15 |
Season to date | Sentinel GP ARI | 759 | 621 | 495 | 62 | 64 | 138 | 0 | 138 |
Non-sentinel respiratory | 1,750 | 1,614 | 1,347 | 137 | 130 | 136 | 20 | 116 |
Total | 2,509 | 2,235 | 1,842 | 199 | 194 | 274 | 20 | 254 |
Appendix Table 6: RSV type
distribution among sentinel GP ARI and non-sentinel respiratory RSV
positive specimens for week 3 2025, week 4 2025 and the 2024/2025
season. Data source: NVRL.
Time period | Specimen source | Total RSV positive | RSV A | RSV B | RSV (unspecified) |
|---|
Week 3 2025 | Sentinel GP ARI | 12 | 2 | 10 | 0 |
Non-sentinel respiratory | 47 | 15 | 31 | 1 |
Total | 59 | 17 | 41 | 1 |
Week 4 2025 | Sentinel GP ARI | 3 | 2 | 1 | 0 |
Non-sentinel respiratory | 24 | 9 | 15 | 0 |
Total | 27 | 11 | 16 | 0 |
Season to date | Sentinel GP ARI | 131 | 63 | 68 | 0 |
Non-sentinel respiratory | 494 | 232 | 261 | 1 |
Total | 625 | 295 | 329 | 1 |
