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.
Key messages
Data for week 52 2024 and week 1 2025 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.
During week 1 2025, influenza activity in Ireland was at very high
levels. Notified influenza cases and hospitalisations continued to
increase and were very high. Sentinel GP influenza positivity increased
to 58.1%, above the 10% positivity threshold. Influenza hospital bed
occupancy increased throughout December, with a slight decrease during
week 1 2025. Influenza A(H1)pdm09 is the predominant influenza virus
circulating, with influenza A(H3) and B detections reported at a lower
level. RSV notifications and hospitalisations continued to increase,
particularly in those aged less than five years. COVID-19 activity
remained at low to moderate levels during week 1 2025.
Summary for week 1
2025
Primary Care Surveillance
The sentinel GP Acute Respiratory Infection (ARI) consultation rate
increased to 210.1/100,000 population in week 1 2025, with the highest
rates in those aged <5 years. Sentinel GP positivity for influenza
continued to increase and was well above the 10% positivity threshold
levels at 58.1%. Sentinel GP RSV positivity was below the baseline
threshold. Rhino or Enterovirus positivity has decreased in recent weeks
and is now below the 10% positivity threshold. All other seasonal
respiratory pathogens are circulating at lower levels. The proportion of
GP-OOH calls for self-reported cough and flu calls were above the
threshold for all age groups in week 1 2025.
COVID-19
COVID-19 activity remained at low-moderate levels across all
indicators in week 1 2025, however there was an increase compared to
week 52. COVID-19 cases increased by 83.0%, from 120 cases notified in
week 52 to 219 cases in week 1. Hospitalised cases increased by 25.0%,
with 69 cases in week 1 compared to 55 cases in week 52. ICU admissions
and deaths remained low. The XEC lineage became the dominant variant and
accounted for 46.7% of sequences between weeks 45 and 49 2024.
Influenza
Influenza activity continued to increase in recent weeks and
influenza is currently circulating at very high levels. During week 1
2025 the overall notification rate was 73.8/100,000 population and was
highest in those aged ≥80 years at 365.1/100,000 population, followed by
those aged less than five years. The number of notified influenza cases
increased by 64% from 2315 in week 52 2024 to 3802 cases in week 1 2025.
There were 956 hospitalisations, 15 ICU admissions and seven deaths
notified during week 1 2025. For the season to date (weeks 40 2024-1
2025), 69 ICU admissions and 32 deaths have been reported. Influenza
hospital bed occupancy increased throughout December and there was a
slight decrease during week 1 2025. Influenza A(H1)pdm09 is the
predominant virus circulating, with influenza A(H3) and B detected at
lower levels.
RSV
The number of notified RSV cases remained at high levels during week
1 2025, with 794 cases notified compared to 629 in week 52 and 835 in
week 51. The overall notification rate was 15.4/100,000 population and
was highest in those aged less than one year at 373.7/100,000 population
during week 1 2025. There were 252 hospitalisations and one ICU
admission in week 1 2025. For the season to date, 44 ICU admissions and
two deaths have been reported (weeks 40 2024-1 2025).
Severe Acute Respiratory Infection (SARI)
The number and incidence of SARI cases presented in this report are
an underestimate for week 52 2024 and week 1 2025, as case ascertainment
and data collection are ongoing in two sentinel hospital sites (SVUH and
UHL) for this period. Based on the data from one hospital site (SJH),
the number of SARI cases increased by 31.4%, from 51 cases in week 52 to
67 cases in week 1 2025. Based on data available from two sentinel
hospital sites, in week 1 2025, influenza positivity was 48.1%, while
RSV positivity was 4.7% (note: no paediatric data available) and
SARS-CoV-2 positivity was 0%.
Outbreaks
COVID-19 outbreaks increased in week 1 2025 compared to week 52 2024.
A total of 12 COVID-19 outbreaks were reported during week 1 2025,
including four in hospitals and five in nursing homes. One mixed
COVID-19 and influenza outbreak was notified by a nursing home in Dublin
and Midlands region during week 1. The number of influenza outbreaks has
increased over the last few weeks, with 60 influenza outbreaks (15 in
hospitals, 32 in nursing homes, five in community hospitals, seven in
residential institutions and one in a non-healthcare setting) notified
during week 1 2025. There were also two RSV outbreaks (one in a nursing
home and one in a residential institution) and 13 other ARI outbreaks
(10 in nursing homes, one in a hospital, one in a community hospital and
one in a residential institution) notified during week 1 2025.
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.
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 07/12/2024). The SARS-CoV-2 sequencing results included
in this report reflect all data available as of 06/01/2025.
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
