Australian Respiratory
Surveillance Report
Viral Respiratory Diseases Epidemiology and Surveillance Section
Report 8, 2024

Key messages
This report presents a national epidemiological update for coronavirus disease 2019 (COVID-19),
influenza and respiratory syncytial virus (RSV) with a focus on the current reporting period (1 July to
14 July 2024) and earlier severity reporting periods (up to 30 June 2024).
Activity: In this year to date, respiratory illness activity (self-reported new fever and coughsymptoms) in the community has been higher than the levels of activity observed at the sametime last year. General practice consultation rates for respiratory illnesses (new fever andcough symptoms) monitored through sentinel surveillance sites have increased in the last
fortnight and are slightly higher than consultation rates observed in most previous years. In thisfortnight, nationally notified COVID-19 cases and RSV cases have decreased compared withthe previous fortnight, though this trend was not observed across all jurisdictions. Nationally,
notified influenza cases have risen steeply since late April 2024 to an apparent peak in theweek ending 7 July 2024. However, this trend has not been consistent across jurisdictions, and
it is too early to determine a peak in the 2024 influenza season.
Severity: The number of patients hospitalised with COVID-19, monitored through sentinel
hospital-based surveillance, has continued to decrease in recent weeks after following an
increasing trend since March 2024. The number of patients hospitalised with influenza,
monitored through sentinel hospital-based surveillance, has followed an increasing trend sinceApril 2024. In 2024, the proportion of those patients with a severe acute respiratory infection(SARI) who were admitted directly to an intensive care, monitored through sentinel hospitalbased surveillance, has remained low and stable. Nationally, the number of patients admitted tosentinel intensive care surveillance sites with COVID-19 or influenza have increased in recent
weeks, whereas the number of patients admitted with RSV have followed a decreasing trend
since May 2024. Patients with COVID-19 accounted for more than half of the SARI admissions
at sentinel intensive care surveillance sites.
At-risk populations: For patients admitted with a SARI to sentinel intensive care sites, thelargest proportion of in-hospital mortality has been in those aged 60 years or over. Nationally,
age-specific mortality rates for COVID-19, influenza and RSV cases have been highest among
those aged 70 years or over.
Impact: The proportion of people taking time off work due to respiratory illness (self-reported
new fever and cough symptoms) decreased in the last fortnight, compared with the previous
fortnight. Nationally, the mean number of COVID-19 cases in intensive care and the mean
number of intensive care staff unavailable due to COVID-19 illness or exposure each fortnight
decreased during the last fortnight.
Genomic surveillance and virology: Nationally, the Omicron BA.2.86 sublineage, JN.1,
remains the dominant circulating sub-lineage (which includes the KP, JN.1.17, and JN.1.8 subsub-lineages). The KP.3 sub-sub-lineage represents the most common JN.1 sub-lineage in
AusTrakka, followed KP.2, JN.1.18 and JN.1.7. In this year to date, influenza A has accounted
for most influenza notifications nationally.
Vaccine coverage, effectiveness and match: It is too early to assess influenza vaccine
coverage or effectiveness for the 2024 influenza season. COVID-19 and RSV vaccination data
will be included in future iterations of the Australian Respiratory Surveillance Report.

Interim Australian Centre for Disease Control

1

Introduction
This report presents a national overview of acute viral respiratory infections in Australia, including
COVID-19, influenza and RSV, drawing information from several different surveillance systems. Our
surveillance systems help us to understand the distribution of acute viral respiratory illness activity inthe community, the severity of disease, which populations might be at risk of severe disease, andthe impact of acute viral respiratory illness on the community and health system in Australia.
Surveillance indicators presented in this report are based on the Australian National Surveillance
Plan for COVID-19, Influenza, and RSV.
The COVID-19 pandemic has had considerable impact on acute respiratory infection activity inAustralia, which should be taken into consideration when interpreting the Australian Respiratory
Surveillance Report. A summary of data considerations for the Australian Respiratory Surveillance
Report are provided below. Refer to the Technical Supplement – Australian Respiratory
Surveillance Report for further detail on our surveillance sources and data considerations.

Data considerations•

Data in this report are presented by International Organization for Standardization (ISO)8601 weeks, with the week ending on Sunday. Throughout the report, where the year to dateis presented, this includes data from 1 January to 14 July 2024.

•

Due to the dynamic nature of the surveillance systems used in this report, data provided forthe current and most recent weeks may be incomplete. All data are preliminary and subject
to change as updates are received, with the most recent weeks considered particularly
subject to revisions. Data in this report may vary from data reported in other national reports
and reports by states and territories.

•

In Australia, states and territories report notified cases to the National Notifiable Diseases
Surveillance System (NNDSS) based on the Australian national surveillance casedefinitions. From 1 July 2024, only laboratory-confirmed COVID-19 cases are notified to the
NNDSS and included in this report (except where specified otherwise). For influenza and
RSV, only laboratory-confirmed cases are notified to the NNDSS and included in this report.

•

Data from the NNDSS are analysed and reported based on diagnosis date, which is the true
onset date of a case if known, otherwise it is the earliest of the specimen date, thenotification date, or the notification received date. NNDSS data were extracted on
Wednesday 17 July 2024.

•

To account for the lag in collection and provision of severity data from some surveillancesystems, and for the time delay between illness onset and the development of severe
disease outcomes, cases with an admission date or a diagnosis date in the last two weeks
are excluded from severity analyses, which includes analyses of hospitalisations, intensive
care admissions and deaths. As such, the severity reporting periods are two weeks behindthe current reporting period. For this report, where the year to date for severity reporting ispresented, this includes data from 1 January to 30 June 2024.

•

While every care has been taken in preparing this report, the Australian Government
Department of Health and Aged Care does not accept liability for any injury or loss ordamage arising from the use of, or reliance upon, the content of the report and the relevantTechnical Supplement. For further details about information contained in this report pleaserefer to the Technical Supplement – Australian Respiratory Surveillance Report or contact
the Viral Respiratory Diseases Epidemiology and Surveillance Section(respiratory.surveillance@health.gov.au).

Interim Australian Centre for Disease Control

2

1. Activity
Activity measures the capacity of the circulating respiratory viruses to spread fromperson to person and may be measured indirectly through systems that monitor acuterespiratory illnesses and more directly through systems that monitor cases.

1.1 Community-based surveillance
FluTracking•

This fortnight (1 July to 14 July 2024), the mean incidence of new fever and cough among
FluTracking participants was 2.2%, a slight decrease compared with the mean incidence of
2.4% in the previous fortnight (Figure 1). Note, FluTracking data are age standardised.

•This fortnight, 13.9% (215/1,548) of FluTracking participants who reported new fever andcough symptoms reported testing for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) with a polymerase chain reaction (PCR) test and 65.6% (1,016/1,548)
reported testing with a rapid antigen test (RAT) (noting that in some instances a RAT will befollowed by a PCR test for the same participant, or vice versa).
–•

This fortnight, 19.7% (305/1,548) of FluTracking participants with new fever and coughsymptoms reported testing for influenza with a PCR test.
–•

This fortnight, the self-reported percent positivity among participants with new feverand cough symptoms increased for SARS-CoV-2 PCR tests (13.5%; 29/215) anddecreased for RATs (27.8%; 282/1,016) compared with the previous fortnight (10.9%[29/265] and 29.2% [361/1,235] respectively).

This fortnight, the self-reported percent positivity among participants with new feverand cough symptoms increased for influenza PCR tests (40.3%; 123/305), comparedwith the previous fortnight (39.6%; 151/381).

In the year to date, the incidence of new fever and cough symptoms reported to FluTracking
has fluctuated, peaking in the week ending 30 June 2024 at 2.6% (Figure 1). The incidenceof fever and cough is currently similar to the proportion observed in the same period in mostprevious years and the five-year mean (Figure 1).

Interim Australian Centre for Disease Control

3

Figure 1: Age standardised percentage of FluTracking participants reporting new fever andcough symptoms compared with the five-year mean by year and week of report*, Australia,
2017 to 14 July 2024

* FluTracking has expanded the reporting period from 2020 onwards due to COVID-19. As such, five-year historical comparisons are notavailable for data reported before May and after October for any year before 2020. The years 2020 and 2021 are excluded whencomparing the current season to historical periods when influenza virus has circulated without public health restrictions. As such, the fiveyear mean includes the years 2017 to 2019 and 2022 to 2023. Please refer to the Technical Supplement for interpretation of the five-year
mean and for notes on impact of COVID-19 on FluTracking data.

Australian Sentinel Practice Research Network (ASPREN)•

This fortnight (1 July to 14 July 2024), a mean rate of 12.2 per 1,000 consultations per
fortnight due to new fever and cough symptoms were reported by ASPREN sentinel generalpractitioners and nurse practitioners. This is an increase compared with 11.8 per 1,000
consultations in the previous fortnight (Figure 2).

•

This fortnight, 153 people presented to ASPREN sentinel general practitioners and nurse
practitioners with new fever and cough symptoms and were tested for respiratory pathogens.
Of those, 67.3% (103/153) have tested positive for a respiratory pathogen.
–Among those positive for a respiratory pathogen, the most common respiratory
pathogen reported was influenza (40.8%; 42/103). Other respiratory pathogens
detected included rhinovirus (23.3%; 24/103), SARS-CoV-2 (9.7%; 10/103), and RSV(6.8%; 7/103).

•

In the year to date, the rate of new fever and cough symptoms per 1,000 consultations per
week has largely remained above the rate observed in the corresponding weeks of earlier
years (excluding 2019 and 2022) and the five-year mean (Figure 2).

•

In the year to date, 1,341 people presented to ASPREN sentinel general practitioners andnurse practitioners with new fever and cough symptoms and have been tested for respiratory
pathogens. Of those, 67.3% (903/1,341) have tested positive for a respiratory pathogen.
–Among those positive for a respiratory pathogen, the most common respiratory
pathogen reported has been rhinovirus (32.8%; 296/903). Other respiratory
pathogens detected included influenza (20.7%; 187/903), SARS-CoV-2 (14.7%;
133/903), RSV (10.9%; 98/903), Mycoplasma pneumoniae (7.3%; 66/903) andadenovirus (4.2%; 38/903).

Interim Australian Centre for Disease Control

4Figure 2: Rate of new fever and cough symptoms per 1,000 consultations per week with
ASPREN sentinel general practitioners and nurse practitioners compared with the five-year
mean by year and week of consultation*†, Australia, 2017 to 14 July 2024

* The years 2020 and 2021 are excluded when comparing the current season to historical periods when influenza virus has circulated
without public health restrictions. As such, the five-year mean includes the years 2017 to 2019 and 2022 to 2023. Please refer to theTechnical Supplement for interpretation of the five-year mean.
† Please refer to the Technical Supplement for notes on impact of COVID-19 on ASPREN data.

Wastewater surveillance
At present, there are no national wastewater surveillance data for SARS-CoV-2, influenza, or RSV.
For information regarding SARS-CoV-2 wastewater surveillance at the jurisdictional level, pleaserefer to the state and territory health webpages and/or respiratory surveillance reports.

1.2 Laboratory-based surveillance
Sentinel laboratories, including National Influenza Centres•

This fortnight (1 July to 14 July 2024), 4.0% (851/21,075) of samples tested for SARS-CoV-2
across sentinel laboratories have been positive for SARS-CoV-2, a decrease in positivity
compared with the previous fortnight (6.0%; 1,205/20,231) (Figure 3).

•

This fortnight, 16.7% (4,113/24,617) of the samples tested for influenza across sentinellaboratories have been positive for influenza, an increase in positivity compared with theprevious fortnight (12.0%; 2,796/23,217) (Figure 3).

•

This fortnight, 5.2% (1,089/21,075) of the samples tested for RSV across sentinellaboratories have been positive for RSV, a small increase in positivity compared with theprevious fortnight (4.8%; 976/20,231) (Figure 3).

•

This fortnight, the most commonly detected respiratory viruses by sentinel laboratory site
and week were:–

New South Wales: influenza A (both weeks)–South Australia: rhinovirus (week 27) and influenza A (week 28)–

Tasmania: influenza A (both weeks)Interim Australian Centre for Disease Control

5

•

–

Victoria: influenza A(week 27) and RSV, picornavirus, parainfluenza virus, seasonalcoronavirus (week 28)–

Western Australia: influenza A (both weeks).

In the year to date, 5.3% (10,457/196,023) of samples tested for SARS-CoV-2 have been
positive for SARS-CoV-2, 6.3% (14,497/228,690) of samples tested for influenza have been
positive for influenza and 3.0% (5,789/196,023) of samples tested for RSV have been
positive for RSV (Figure 3).

Figure 3: Total number of specimens tested by sentinel laboratories and proportion of
positive sentinel laboratory tests by pathogen and week of report*†, 1 January to 14 July2024

* Number of specimens tested excludes data from Western Australia as testing denominator data are different for the three pathogens inWestern Australia.
† A small minority of total samples from Victoria are tested only by respiratory panel (influenza, parainfluenza, adenovirus, human
metapneumovirus, seasonal coronaviruses, RSV, and some picornaviruses) but not for SARS-CoV-2. These minority samples include
only forensic materials; all other samples are tested by respiratory panel and SARS-CoV-2 assay.

1.3 Case-based surveillance
NNDSS•

In this fortnight, nationally notified COVID-19 cases and RSV cases have decreased
compared with the previous fortnight, though this trend was not observed across all
jurisdictions. Nationally, notified influenza cases have risen steeply since late April 2024 toan apparent peak in the week ending 7 July 2024. However, this trend has not been
consistent across jurisdictions, and it is too early to determine a peak in the 2024 influenza
season.

Interim Australian Centre for Disease Control

6

Table 1: Notifications to the NNDSS and notification rate per 100,000 population by disease,
five-year age group, and jurisdiction*†, Australia, 1 January to 14 July 2024
COVID-19
Reportingfortnight(n)Influenza

RSV

Year todate(n)Year todate(rate)

Reportingfortnight(n)Year todate(n)Year todate(rate)

Reportingfortnight(n)Year todate(n)Year todate(rate)

Age group (years)
0–4

1,101

14,802

976.4

7,582

26,8901,773.7

4,530

64,6004,261.2

5–9

348

4,038

250.7

7,620

31,086

1,930.3

970

10,089

626.5

10–14

301

4,138

249.7

4,599

19,795

1,194.4

520

4,689

282.9

15–19

354

5,042

313.4

2,955

12,325

766.1

248

2,467

153.3

20–24

395

5,984

345.5

2,539

9,205

531.5

174

1,903

109.9

25–29

542

7,755

403.6

2,810

10,166

529.0

189

2,203

114.6

30–34

705

9,189

463.5

3,243

11,701

590.2

264

2,937

148.1

35–39

714

9,935

512.7

3,626

13,069

674.4

301

2,935

151.5

40–44

709

9,454

531.1

3,098

12,056

677.2

252

2,418

135.8

45–49

653

8,731

540.9

2,305

9,308

576.6

253

2,334

144.6

50–54

647

9,283

552.5

2,181

8,653

515.0

327

2,918

173.7

55–59

679

9,141

600.0

1,765

7,192

472.0

292

2,904

190.6

60–64

772

9,857

649.9

1,716

6,850

451.6

316

3,304

217.8

65–69

801

10,420

785.3

1,365

5,534

417.0

313

3,280

247.2

70+

4,554

64,6162,000.5

3,923

16,449

509.3

1,341

13,817

427.8

ACT

225

3,195

684.4

791

2,388

511.6

214

2,289

490.3

NSW

6,864

80,606966.6

31,092

111,493

1,337.0

3,790

56,535

677.9

NT

127

1,884

746.2

49

2,103

833.0

50

1,223

484.4

QLD

3,626

41,374

757.8

6,146

31,068

569.1

1,775

27,729

507.9

SA

716

12,786

690.5

2,752

9,226

498.2

1,689

6,433

347.4

TAS

167

3,153

550.5

589

1,634

285.3

199

1,325

231.3

VIC

2,178

30,563

448.6

8,519

36,328

533.3

1,829

24,091

353.6

WA

656

10,261

356.5

1,393

6,057

210.4

744

3,189

110.8

Total

14,559183,822690.1

51,331

200,297751.9

10,290122,814461.0

Jurisdiction* Rate per 100,000 population for the given time period. Population data are based on the Australian Bureau of Statistics (ABS) EstimatedResident Population (ERP) as at June 2023.
† Total includes cases with missing age.

Interim Australian Centre for Disease Control

7•Nationally, COVID-19 notifications continued to decrease this fortnight, compared with thelast fortnight. This year to date, COVID-19 notifications followed a decreasing trend fromJanuary through to mid-April before increasing to an apparent peak in early June 2024
(Figure 4).

•

Nationally, there were 14,559 COVID-19 notifications with a diagnosis date this fortnight (1July to 14 July 2024), a decrease compared with 19,213 notifications in the previous fortnight(Figure 4).

•

In the year to date, there have been 183,882 COVID-19 notifications reported to the NNDSS.
This is lower than the number of laboratory-confirmed notifications in the same period in
2023; however, this trend should be interpreted with caution due to a reduction in caseascertainment and reporting in all jurisdictions (Figure 4).

•

In the year to date, COVID-19 notification rates have been highest in people aged 70 years
or over, followed by children aged 0–4 years (Table 1).
–

The trend for older age groups is likely to be a reflection of higher caseascertainment due to targeted testing strategies in place for populations at-risk ofsevere disease and who live in a high-risk setting, such as a residential aged carehome.

Figure 4: COVID-19 cases notified to the NNDSS showing (A) laboratory-confirmed andprobable cases in all pandemic years 2020–2024 and (B) laboratory-confirmed cases inrecent pandemic years 2023 and 2024 by year and week of diagnosis, Australia, 1 January
2020 to 14 July 2024•

This fortnight, COVID-19 notification rates have continued to decrease in all jurisdictions
compared with the previous fortnight (Figure 5).

Interim Australian Centre for Disease Control8•In the year to date, COVID-19 notification rates have been highest in New South Wales,
followed by Queensland (Table 1).

Figure 5: Notification rates per 100,000 population for COVID-19 cases notified to the
NNDSS* by state or territory and week of diagnosis, Australia, 1 January to 14 July 2024

* Rate per 100,000 population for the given time period. Population data are based on the ABS ERP as at June 2023.

•

Nationally, influenza notifications have risen steeply since late April 2024 to an apparent
peak in the week ending 7 July 2024. However, this trend has not been consistent acrossjurisdictions, and it is too early to determine a peak in the 2024 influenza season (Figure 6).

•

Nationally, there were 51,331 influenza notifications with a diagnosis date this fortnight, an
increase compared with 46,975 notifications in the previous fortnight (Figure 6).

•

In the year to date, there have been 200,297 influenza notifications reported to the NNDSS,
which is higher than the number of notifications in the same period in all other years(excluding 2022 where the influenza season peaked earlier in the year and at a greaternumber of notifications) and the five-year mean (Figure 6).
–•

The higher number of influenza notifications observed during the most recent
interseasonal period (typically November to the following March) may have been due
to an increase in influenza circulation in the community. However, it may also havebeen influenced by changes in health-seeking behaviour, such as increasedlaboratory testing for viral respiratory infections, associated with increases in COVID19 activity observed in many jurisdictions from late 2023 into early 2024.

In the year to date, influenza notification rates have been highest in children aged 5–9 years,
followed closely by children aged 0–4 years (Table 1).

Interim Australian Centre for Disease Control

9Figure 6: Influenza cases notified to the NNDSS and five-year mean* by year and week ofdiagnosis, Australia, 2017 to 14 July 2024

* The years 2020 and 2021 are excluded when comparing the current season to historical periods when influenza virus has circulated
without public health restrictions. As such, the five-year mean includes the years 2017 to 2019 and 2022 to 2023. Please refer to theTechnical Supplement for interpretation of the five-year mean.

•

This fortnight, influenza notifications continued to increase or remained stable across all
jurisdictions, except New South Wales, where a decrease compared with the previous
fortnight was observed (Figure 7). This fortnight, notification rates in New South Walesremain considerably higher than notification rates all other jurisdictions.

•

In the year to date, influenza notification rates have been highest in New South Wales,
followed by the Northern Territory (Table 1).

Figure 7: Notification rates per 100,000 population for influenza cases notified to the NNDSS*
by state or territory and week of diagnosis, Australia, 1 January to 14 July 2024

* Rate per 100,000 population for the given time period. Population data are based on the ABS ERP as at June 2023.

Interim Australian Centre for Disease Control

10•Nationally, RSV notifications continued to decrease this fortnight, compared with the last
fortnight. This year to date, RSV notifications followed an increasing trend from January
through to an apparent peak in late May 2024 and have followed a decreasing trend since(Figure 8).

•

Nationally, there were 10,290 RSV notifications with a diagnosis date this fortnight, adecrease compared with 12,416 notifications in the previous fortnight (Figure 8).

•

In the year to date, there have been 122,814 RSV notifications reported to the NNDSS,
which is over 1.5 times the number of RSV notifications in the same period in 2023 (Figure
8).
–

•

The higher number of RSV notifications observed during the period January to March2024 may have been due to an increase in RSV circulation in the community.
However, it may also have been influenced by changes in health-seeking behaviour,such as increased laboratory testing for viral respiratory infections, associated withincreases in COVID-19 activity observed in many jurisdictions from late 2023 into
early 2024. Note, RSV notifications are not available nationally for historicalcomparisons prior to January 2023.

In the year to date, RSV notification rates have been highest in children aged 0–4 years,
followed by children aged 5–9 years (Table 1).

Figure 8: RSV cases notified to the NNDSS by year and week of diagnosis*, Australia, 2023 to
14 July 2024•

This fortnight, RSV notification rates decreased or remained stable in most jurisdictions,
except in South Australia and Western Australia where an increase was observed comparedwith the previous fortnight (Figure 9).

•

In the year to date, RSV notification rates have been highest in New South Wales, followed
by Queensland (Table 1).

Interim Australian Centre for Disease Control

11

Figure 9: Notification rates per 100,000 population for RSV cases notified to the NNDSS* bystate or territory and week of diagnosis, Australia, 1 January to 14 July 2024

* Rate per 100,000 population for the given time period. Population data are based on the ABS ERP as at June 2023.

For further information regarding respiratory virus activity at the jurisdictional level, please refer tothe state and territory health respiratory surveillance reports.

Interim Australian Centre for Disease Control

12

2. Severity*
The severity of acute respiratory infections is measured as those who are hospitalised,admitted to intensive care, or have died. Measuring and understanding severity
quantifies the most significant health impacts of circulating respiratory viruses.

2.1 Hospital-based surveillance
In interpreting data from hospital-based sentinel systems, it is important to note these data reflect
the sickest patients with severe acute respiratory infections who are hospitalised or admitted tointensive care; data are therefore not generalisable to all cases or patients in hospital.

Influenza Complications Alert Network (FluCAN)In FluCAN sentinel hospitals RSV surveillance commenced on 1 April 2024; however, due tounforeseen issues RSV data are not yet available. These data will be included in future iterations of
the Australian Respiratory Surveillance Report.
•

In this fortnight for FluCAN severity reporting (17 June to 30 June 2024), there were 615
patients admitted with a severe acute respiratory infection (SARI) to FluCAN sentinel
hospitals, of whom 6.8% (42/615) were admitted directly to intensive care (Figure 10).

•In the year to date for FluCAN severity reporting (1 January to 30 June 2024), there havebeen 4,462 patients admitted with a SARI to FluCAN sentinel hospitals, of which 6.5%
(288/4,462) have been admitted directly to intensive care (Figure 10).

•In the year to date for FluCAN severity reporting, there have been 2,969 patients admittedwith COVID-19 to FluCAN sentinel hospitals, of whom 6.8% (202/2,969) were admitted
directly to intensive care (Figure 10). This excludes 35 patients with COVID-19 admitted to
FluCAN sentinel hospitals with a missing admission location. The number of patients
admitted with COVID-19 to FluCAN sentinel hospitals each week reached an apparent peakin the week ending 19 May 2024, and a decreasing trend in the number of patients admittedwith COVID-19 each week has been observed since the apparent peak (Figure 10).

•–For patients admitted with COVID-19 to FluCAN sentinel hospitals, the median lengthof stay in hospital was 3 days (interquartile range [IQR]: 2–6 days).

–Note, all length of stay calculations exclude patients that acquired their infection in
hospital. Please see the Technical Supplement for further detail.

Since influenza surveillance commenced on 1 April 2024 to date for FluCAN severity
reporting (30 June 2024), there have been 1,492 patients admitted with influenza to FluCAN
sentinel hospitals, of whom 5.8% (86/1,492) were admitted directly to intensive care (Figure10). The number of patients admitted with influenza to FluCAN sentinel hospitals each week
has followed an increasing trend since influenza surveillance commenced (Figure 10).
–For patients admitted with influenza to FluCAN sentinel hospitals, the median lengthof stay in hospital was 2 days (IQR: 1–4 days).

* To account for the lag in collection and provision of severity data from some surveillance systems, and for the time delay between illness
onset and the development of severe disease, cases with a diagnosis date in the last two weeks are excluded from severity analyses
which include analyses of hospitalisations, intensive care admissions and deaths. For this reason, the severity reporting periods are two
weeks behind the current reporting period.

Interim Australian Centre for Disease Control

13

Figure 10: Number of patients admitted with a severe acute respiratory infection to FluCAN
sentinel hospitals by disease, admission location and week of admission*†‡, Australia, 1January to 30 June 2024

* Axis varies between disease groups.
† Excludes 35 patients with a severe acute respiratory infection admitted to FluCAN sentinel hospitals with a missing admission location.
‡ Admission location reflects the initial admission ward; some patients may be initially admitted to general ward then later admitted to an
intensive care and this is not reflected here.

Short Period Incidence Study of Severe Acute Respiratory Infection(SPRINT-SARI) Australia (last updated 5 July 2024)
This section will be updated every four weeks; therefore, reporting periods presented here may notalign with other sections of the report. Note, intensive care includes intensive care units and highdependency units that are managed by an intensive care team.
•In the most recent 28-day period for SPRINT-SARI severity reporting (20 May to 16 June2024), there were 205 patients admitted with a SARI to a SPRINT-SARI sentinel intensive
care. Patients with COVID-19 accounted for the highest proportion of patients admitted witha SARI to a SPRINT-SARI sentinel intensive care during this time (Figure 11).

•In the year to date for SPRINT-SARI severity reporting (1 January to 16 June 2024), there
have been 1,096 patients admitted with a SARI to a SPRINT-SARI sentinel intensive care
(Figure 11). This includes:–

53.2% (583/1,096) patients with SARS-CoV-2–

16.1% (176/1,096) patients with influenza–

14.2% (156/1,096) patients with RSVInterim Australian Centre for Disease Control

14–19.0% (208/1,096) patients with other respiratory pathogens including parainfluenza
and rhinovirus.

•

Approximately 2.4% (26/1,096) of patients had co-infections of multiple pathogens;therefore, the sum of pathogen-specific totals above may not equal the total number ofpatients.

•

In the year to date for SPRINT-SARI severity reporting, for all patients admitted with a SARI
to a SPRINT-SARI sentinel intensive care, the median duration of mechanical ventilation
was 3.0 days (IQR: 1.2–7.2 days), the median length of stay in intensive care was 2.8 days
(IQR: 1.6–5.3 days), and the median length of stay in hospital was 7.5 days (IQR: 4.5–14.2days).

•In the year to date for SPRINT-SARI severity reporting, most patients admitted with a SARI
(68.5%; 751/1,096) have been discharged home, 6.7% (73/1,096) died in intensive care and2.9% (32/1,096) died within a general hospital ward after intensive care admission, with an
overall in-hospital mortality rate of 9.6% (105/1,096) for all patients admitted with a SARI to a
SPRINT-SARI sentinel intensive care.
–

Note, deaths in patients admitted with a SARI to a SPRINT-SARI sentinel intensive
care may not necessarily represent a death due to SARI.

Figure 11: Number of patients admitted with severe acute respiratory infections to a SPRINTSARI sentinel intensive care by disease*† and week of admission, Australia, 1 January to 16
June 2024* Axis varies between disease groups.
† Includes nine patients with viral co-infection of SARS-CoV-2/influenza/RSV in the year to date for severity reporting.
Interim Australian Centre for Disease Control

15

Table 2: Outcomes for patients admitted with a severe acute respiratory infection(s) to a
SPRINT-SARI sentinel intensive care by disease*†‡, Australia, 1 January to 16 June 2024
COVID-19
Severity
reportingperiod(n=112)

Influenza

Year todate
for severity
reporting(n=583)

RSV

Other

Severity
reportingperiod(n=48)

Year todate
for severity
reporting(n=176)

Severity
reportingperiod(n=24)

Year todate
for severity
reporting(n=156)

Severity
reportingperiod(n=25)

Year todate
for severity
reporting(n=208)20(41.7%)

61(34.7%)

6(25.0%)

38(24.4%)

10(40.0%)

64(30.8%)

3.0[1.7–7.2]

4.9[2.2–8.8]

2.5[1.8–3.2]

4.4[2.3–6.7]

3.9[2.1–6.1]

3.1[1.5–6.9]

2.7[1.6–4.9]

3.3[2.6–5.7]

3.4[2.0–6.3]

2.7[1.5–4.5]

2.8[1.6–4.6]

2.7[1.6–3.9]

2.9[1.7–5.5]

6.9[4.7–13]

7.9[4.6–15]

6.8[4.0–11]

8.2[4.8–14]

8.3[6.0–14]

6.8[4.3–12]

6.6[5.0–11]

7.1[3.8–14]

Ongoing care inintensive care18
(16.1%)

40(6.9%)

9(18.8%)

13(7.4%)

4(16.7%)

9(5.8%)

4(16.0%)

8(3.8%)

Ongoing care in
hospital ward*

20(17.9%)

32(5.5%)

3(6.3%)

5(2.8%)

4(16.7%)

6(3.8%)

3(12.0%)

8(3.8%)

Transfer toother hospital or
facility

5(4.5%)

49(8.4%)

4(8.3%)

8(4.5%)

1(4.2%)

7(4.5%)

1(4.0%)

15(7.2%)

Transfer torehabilitation3(2.7%)

26(4.5%)

1(2.1%)

4(2.3%)

0
(0%)

0
(0%)

0
(0%)

6
(2.9%)

Dischargehome

52(46.4%)

362(62.1%)

28(58.3%)

128(72.7%)

13(54.2%)

123(78.8%)

17(68.0%)

160(76.9%)

Death† –intensive care†

7(6.3%)

46(7.9%)

2(4.2%)

12(6.8%)

0(0%)

8(5.1%)

0(0%)

9(4.3%)

Death† –hospital ward†

6(5.4%)

23(3.9%)

0(0%)

5(2.8%)

1(4.2%)

2(1.3%)

0(0%)

2(1.0%)

Missing‡1(0.9%)

5(0.9%)

1(2.1%)

1(0.6%)

1(4.2%)

1(0.6%)

0
(0%)

0
(0%)

Received invasive mechanical ventilation
Number (%)

35(31.3%)

176(30.2%)

Duration of invasive mechanical ventilation (days)
Median [IQR]

1.9[0.7–2.6]

2.3[0.9–6.8]

Length of intensive care stay (days)
Median [IQR]

2.9[1.7–4.9]

Length of hospital stay (days)
Median [IQR]
Patient outcome

Note: Includes four patients with viral co-infection of multiple pathogens in the 28-day severity reporting period and 26 patients with viralco-infection of multiple pathogens in the year to date for severity reporting. For patients whom are still receiving treatment in intensive
care data may not be complete; therefore, data are not included in the duration of ventilation or length of intensive care stay.
* Patients who have been admitted in intensive care/hospital wards with no discharge information for less than 90 days have been
assumed to have ongoing care in the hospital.
† Death may not necessarily represent a death due to the disease.
‡ Patients who have no outcome entered or have been admitted to intensive care/hospital wards for more than 90 days with no discharge
information have been treated as missing.
Interim Australian Centre for Disease Control

16

2.2 Case-based surveillance
NNDSS
The number of deaths associated with COVID-19, influenza or RSV reported to the NNDSS isbased on data reported to the NNDSS by states and territories. The completeness of information ondeaths in the NNDSS varies, as data are sourced in different ways by state and territories based on
their local surveillance system capabilities, definitions, priorities, and needs. Therefore, the numberof deaths associated with COVID-19, influenza or RSV reported to the NNDSS are likely to be anunderestimate and do not represent the true mortality associated with these diseases. In the
NNDSS, death notifications may not necessarily represent a death due to the disease and publichealth follow-up is not a requirement to determine the outcome of disease. For more detail, pleaserefer to reports and data considerations published by individual jurisdictions, or the TechnicalSupplement – Australian Respiratory Surveillance Report.
•

In the year to date for severity reporting (1 January to 30 June 2024), there have been 1,228
COVID-19-associated deaths notified to the NNDSS (Table 3).

•

In the year to date for severity reporting, there have been 144 influenza-associated deaths
notified to the NNDSS (Table 3).
–•

Of the influenza-associated deaths, 92.4% (133/144) have been attributed toinfluenza A(Unsubtyped), 4.9% (7/144) to influenza A(H1N1), 2.1% (3/144) toinfluenza A(H3N2), and 0.7% (1/144) to influenza B.

In the year to date for severity reporting, there have been 92 RSV-associated deaths notified
to the NNDSS (Table 3).

Table 3: Notifications of deaths to the NNDSS and mortality rates per 100,000 population bydisease and ten-year age groups*†‡, Australia, 1 January to 30 June 2024
COVID-19

Influenza

RSV

Year todate(n)Year todate(rate)

Year todate(n)Year todate(rate)

Year todate(n)Year todate(rate)

0–9

–

–

–

–

–

–

10–19

–

–

–

–

–

–

20–29

–

–

–

–

–

–

30–39

7

0.2

–

–

–

–

40–49

14

0.4

–

–

–

–

50–59

32

1.0

7

0.2

6

0.2

60–69

85

3.0

12

0.4

8

0.3

70+

1,086

33.6

116

3.6

75

2.3

Total

1,228

4.6

144

0.5

92

0.3

Age group (years)

Note: To reduce the risk of re-identification, primary cell suppression has been applied to cells with a value of < 5.
* Rate per 100,000 population for the given time period. Population data are based on the ABS ERP as at June 2023.
† Notified deaths are reported based on diagnosis date not date of death, as date of death data are not collected for influenza or RSV in
the NNDSS. Death may not necessarily represent a death due to the disease.
‡ Total may include cases with missing age.
Interim Australian Centre for Disease Control

17

3. At-risk populations*At-risk populations are people who may be more susceptible to infection with circulating
respiratory viruses and/or who may be more likely to experience severe diseaseassociated with their infection.

3.1 Hospital-based surveillance
In interpreting data from hospital-based sentinel systems, it is important to note these data reflect
the sickest patients with severe acute respiratory infections who are hospitalised or admitted tointensive care; data are therefore not generalisable to all cases or patients in hospital.

FluCAN
There are a higher proportional number of paediatric hospitals that contribute to the FluCAN
dataset. Hospital admissions in children 16 years of age or less are over-represented to provide
enhanced surveillance on this at-risk population. For this reason, paediatric (16 years of age or less)and adult (> 16 years of age) patients in the FluCAN dataset are reported on separately. Please
note, the age distribution of hospital admissions in the FluCAN sentinel surveillance system may notreflect the age distribution of admissions nationally.
In FluCAN sentinel hospitals, RSV surveillance commenced on 1 April 2024; however, due tounforeseen issues RSV data are not yet available. These data will be included in future iterations of
the Australian Respiratory Surveillance Report.
•

In the year to date for FluCAN severity reporting (1 January to 30 June 2024), there havebeen 951 paediatric patients admitted with COVID-19 to FluCAN sentinel hospitals (Figure12). The median age at admission was 1 years (IQR: 0–4 years) and 7.4% (70/951) ofadmissions were among Aboriginal and Torres Strait Islander people.
–•

In the year to date for FluCAN severity reporting, there have been 2,053 adult patients
admitted with COVID-19 to FluCAN sentinel hospitals (Figure 12). The median age at
admission was 75 years (IQR: 62–84 years) and 3.5% (71/2,053) of admissions were among
Aboriginal and Torres Strait Islander people.
–•

The highest proportion of paediatric patients admitted with COVID-19 to FluCAN
sentinel hospitals with a direct admission to intensive care has been in those aged 6months–4 years.

The highest proportion of adult patients admitted with COVID-19 to FluCAN sentinel
hospitals with a direct admission to intensive care has been in those aged 65 years.

In the year to date for FluCAN severity reporting, the greatest proportion of patients admittedwith confirmed COVID-19 to FluCAN sentinel hospitals has been in those aged 65 years orover. This is consistent with trends observed in all previous years, except in 2020 and 2021
when those aged 17–64 years accounted for the largest proportion of admissions to FluCAN
sentinel hospitals (Figure 12).

* To account for the lag in collection and provision of severity data from some surveillance systems, and for the time delay between illness
onset and the development of severe disease, cases with a diagnosis date in the last two weeks are excluded from severity analyses
which include analyses of hospitalisations, intensive care admissions and deaths. For this reason, the severity reporting periods are two
weeks behind the current reporting period.

Interim Australian Centre for Disease Control

18

Figure 12: Number of patients admitted with confirmed COVID-19 to FluCAN sentinel
hospitals by age group, year and week of admission*, Australia, 2020 to 30 June 2024

* Axis varies between years.

•

Since influenza surveillance commenced on 1 April 2024 to date for FluCAN severity
reporting (30 June 2024), there have been 824 paediatric patients admitted with influenza to
FluCAN sentinel hospitals (Figure 13). The median age at admission was 4 years (IQR: 1.8–
8 years) and 8.7% (72/824) of admissions were among Aboriginal and Torres Strait Islander
people.
–•The highest proportion of paediatric patients with influenza admitted to FluCAN
sentinel hospitals with a direct admission to intensive care has been in those aged 5–
16 years.

Since influenza surveillance commenced on 1 April 2024 to date for FluCAN severity
reporting, there have been 668 adult patients admitted with influenza to FluCAN sentinel
hospitals (Figure 13). The median age at admission was 62 years (IQR: 46–76 years) and15.1% (101/668) of admissions were among Aboriginal and Torres Strait Islander people.
–

The highest proportion of adult patients with influenza admitted to FluCAN sentinel
hospitals with a direct admission to intensive care has been in those aged 17–64
years.

Interim Australian Centre for Disease Control

19

Figure 13: Number of patients admitted with confirmed influenza to FluCAN sentinel
hospitals by age group, year and week of admission*†, from April to October, 2017 to 30 June
2024

* Axis varies between years.
† The years 2020 and 2021 are excluded when comparing the current season to historical periods when influenza virus has circulated
without public health restrictions. Please refer to the Technical Supplement for further detail.

Paediatric Active Enhanced Disease Surveillance (PAEDS) (last updated
5 July 2024)
This section will be updated every four weeks; therefore, reporting periods presented here may notalign with other sections of the report.
•

Since the start of the COVID-19 pandemic to date for PAEDS severity reporting (1 January
2020 to 16 June 2024), there have been 199 cases of possible, probable, or confirmed
paediatric inflammatory multisystem syndrome – temporally associated with SARS-CoV-2(PIMS-TS) admitted to PAEDS sentinel hospitals. To date for severity reporting, there havebeen no PIMS-TS associated deaths.

•

Since the start of the COVID-19 pandemic to date for PAEDS severity reporting, the highest
proportion of PIMS-TS cases occurred in 2022 (66.3%; 132/199), followed by 2021 (15.1%;
30/199). The most recent PIMS-TS case admitted to a PAEDS sentinel hospital was
reported in June 2024, noting data have not been updated this fortnight.

•

The majority of PIMS-TS cases have occurred in those aged 5 to < 12 years (52.8%;
105/199), followed by those aged 6 months to < 5 years (28.1%; 56/199). Approximately
5.5% (11/199) of PIMS-TS cases occurred among Aboriginal and Torres Strait Islander
people.

Interim Australian Centre for Disease Control

20

SPRINT-SARI Australia (last updated 5 July 2024)
This section will be updated every four weeks; therefore, reporting periods presented here may notalign with other sections of the report. Note, intensive care includes intensive care units and highdependency units that are managed by an intensive care team.
•In this 28-day period for SPRINT-SARI severity reporting (20 May to 16 June 2024), there
have been 205 patients admitted with a SARI to a SPRINT-SARI sentinel intensive care. The
median age at admission was 63 years (IQR: 48–73 years) and 8.3% (17/205) of patients
admitted with a SARI were among Aboriginal and Torres Strait Islander people.

•

In the year to date for SPRINT-SARI severity reporting (1 January to 16 June 2024), there
have been 1,096 patients admitted with a SARI to a SPRINT-SARI sentinel intensive care.
The median age at admission was 59 years (IQR: 32–71 years) and 55.5% (608/1,096) ofpatients admitted with a SARI have been male. Of the patients admitted with a SARI to a
SPRINT-SARI sentinel intensive care, 8.3% (91/1,096) have been among Aboriginal andTorres Strait Islander people.

•

In the year to date for SPRINT-SARI severity reporting, there have been 105 patients
admitted with a SARI to a SPRINT-SARI sentinel intensive care who died in hospital. The
majority of deaths were in patients aged 60 years or over: 28.6% (30/105) were aged 60–69
years, 33.3% (35/105) were aged 70–79 years, 14.3% (15/105) were aged 80–89 years, and4.8% (5/105) were aged 90 years or over (Figure 14).

Figure 14: Number of patients admitted with severe acute respiratory infections to a SPRINTSARI sentinel intensive care by age group, sex and outcome*†‡, Australia, 1 January to 16
June 2024* The age and sex distribution of severe acute respiratory infection (SARI) intensive care admissions in the SPRINT-SARI Australia
sentinel surveillance system may not reflect the age or sex distribution of all patients admitted with a SARI nationally.
† Ongoing care reflects the need for ongoing care in intensive care. Where a patient has been discharged from intensive care, the patient
may still be receiving ongoing care in a hospital ward.
‡ Death may not necessarily represent a death due to the disease.

Interim Australian Centre for Disease Control

21

3.2 Case-based surveillance
NNDSS
The numbers of deaths in the year to date associated with COVID-19, influenza and RSV notified to
the NNDSS are provided in Table 3. Note, the numbers of deaths associated with COVID-19,
influenza or RSV reported to the NNDSS are likely to be an underestimate and do not represent thetrue mortality associated with these diseases. In the NNDSS, death notifications may notnecessarily represent a death due to the disease.
•

The ascertainment of Indigenous status in the NNDSS for influenza and RSV, and more
recently for COVID-19, remains insufficient for accurate epidemiological assessments or
meaningful interpretation. This is due to a number of factors, including: most laboratory
notifications do not include Indigenous status, case follow-ups are not routinely conducted
and are not a requirement of notification, and data linkage systems that have been used tohelp capture Indigenous status for COVID-19 cases have not been extended for COVID-19
in the post emergency climate, and have not been comprehensively extended to influenza or
RSV cases. For this reason, data are only presented for COVID-19 up to the end of 2023.

•

Since the start of the COVID-19 pandemic to 31 December 2023, there were 437,362
COVID-19 cases and 521 COVID-19-associated deaths among Aboriginal and Torres Strait
Islander people notified to the NNDSS.
–This includes both laboratory-confirmed and probable cases among Aboriginal andTorres Strait Islander people notified to the NNDSS.

–

Readers are encouraged to consult the COVID-19 Epidemiology Reports previously
published in Communicable Diseases Intelligence for information on theepidemiology of COVID-19 in Aboriginal and Torres Strait Islander people in Australia
from the start of the COVID-19 pandemic to 10 March 2024.

•

In the year to date for severity reporting (1 January to 30 June 2024), the rate of COVID-19associated deaths in cases notified to the NNDSS has been highest in those aged 70 years
or over (Table 3). The median age of COVID-19-associated deaths notified is 84 years.

•

In the year to date for severity reporting, the rate of influenza-associated deaths in cases
notified to the NNDSS has been highest in those aged 70 years or over (Table 3). The
median age of influenza-associated deaths notified is 84 years.

•

In the year to date for severity reporting, the rate of RSV-associated deaths in cases notified
to the NNDSS has been highest in those aged 70 years or over (Table 3). The median age
of RSV-associated deaths notified is 86 years.

Interim Australian Centre for Disease Control

22

4. Impact
Impact measures how circulating respiratory viruses adversely affect the community
and the healthcare system.

4.1 Community-based surveillance
FluTracking•

This fortnight (1 July to 14 July 2024), 51.3% (794/1,548) of FluTracking participants
reported taking three or more days off work or normal duties due to fever and coughsymptoms, a decrease compared with 53.8% (955/1,775) in the previous fortnight.

4.2 Hospital-based surveillance
Critical Health Resource Information System (CHRIS)
Note, intensive care includes intensive care units and high dependency units that are managed by
the intensive care team.
•

As of 15 July 2024, 2.8% (50/1,758) of total staffed intensive care beds were occupied by
COVID-19 patients.

•

This fortnight (1 July to 14 July 2024), the mean number of COVID-19 cases in intensive
care across Australia has decreased compared with the previous fortnight (Figure 15). This
fortnight, the mean number of intensive care staff unavailable to work due to COVID-19
exposure or illness across Australia has decreased compared with the previous fortnight(Figure 15).

Figure 15: Mean number of COVID-19 cases in intensive care and the mean number ofintensive care staff unavailable to work due to COVID-19 exposure or illness reported to
CHRIS by week of report*†, Australia, 1 January to 14 July 2024

* Mean number of ventilated and non-ventilated COVID-19 cases in intensive care includes only active COVID-19 cases (those inisolation) and does not include cleared COVID-19 cases.
† Intensive care staff include both medical and nursing staff.

Interim Australian Centre for Disease Control

23•This fortnight, the mean number of COVID-19 cases in intensive care has decreased orremained stable in most jurisdictions compared with the previous fortnight, except inWestern Australia where a small increase was observed compared with the previous
fortnight (Figure 16).

•This fortnight, the mean number of intensive care staff unavailable to work due to COVID-19
exposure or illness decreased or remained stable across all jurisdictions compared with theprevious fortnight (Figure 16).

Figure 16: Mean number of COVID-19 cases in intensive care and the mean number ofintensive care staff unavailable to work due to COVID-19 exposure or illness reported to
CHRIS by jurisdiction and week of report*†‡, Australia, 1 January to 14 July 2024

* Axis varies between jurisdictions.
† Mean number of ventilated and non-ventilated COVID-19 cases in intensive care includes only active COVID-19 cases (those inisolation) and does not include cleared COVID-19 cases.
‡ Intensive care staff include both medical and nursing staff.
Interim Australian Centre for Disease Control

24

5. Genomic surveillance and virology
AusTrakka (last updated 5 July 2024)
Data on SARS-CoV-2 genomics should be interpreted with caution as SARS-CoV-2 sequencing
strategies have changed significantly, and the representativeness of sequences uploaded to
AusTrakka may be limited by the different sample referral pathways for each jurisdiction and asignificant reduction in sequencing across the country. Sequences are reported based on date ofsample collection, not date of sequencing. Due to the small number of sequences received andsome delays in provision of data to AusTrakka, this section will be updated every four weeks;
therefore, reporting periods presented here may not align with other sections of the report.
•

As of 1 July 2024, jurisdictions that have samples with dates of collection during the past 28
days include New South Wales, Queensland, South Australia, Tasmania, Victoria, andWestern Australia, with the most recent collection date being 23 June 2024.

•

As of 1 July 2024, 675 sequences have been uploaded to AusTrakka with dates of collection
within the past 28-day period (3 June to 30 June 2024). All sequences were assigned to theBA.2.86 sub-lineage within B.1.1.529 (Omicron) or recombinants consisting of one or more
Omicron sub-lineages. There were no BA.1, BA.3, BA.4, BA.5 or other BA.2 sub-sub-lineage
sequences identified in the past 28 days (Figure 17).

•

Of the 675 sequences collected in the past 28 days, 98.4% (664/675) were BA.2 sublineages, all from the BA.2.86 sub-lineage, JN.1 (BA.2.86.1.1) (Figure 17). This includes the
KP, JN.1.17, and JN.1.8 sub-sub-lineages. The remaining 1.6% (11/675) were recombinantor recombinant sub-lineages. Recombinant lineages sequenced included XDK and XDV,
recombinants of BA.2.86* and XBB.1.91.

•

The proportion of JN.1 sequences has been consistent (98.4%; 664/675) in the past 28-day
period, compared with the previous 28-day period.

•

The World Health Organization have identified certain sub-sub-lineages and recombinants
as variants under monitoring (VUM) or variants of interest (VOI) because of theirepidemiological, pathological, or immunological features of concern. A select number ofdesignated VUM or VOI are highlighted below due to their relevance in the Australian
context:–

As of 3 May 2024, four new VUMs were designated by the WHO, JN.1.7, KP.2, KP.3
and JN.1.18.

–

The number of KP.3 sequences continues to be high and represents most (60.2%;
400/664) of the JN.1 sub-lineages in AusTrakka in the past 28-day period.

–

There have been 60 KP.2 sequences, five JN.1.18 sequences and two JN.1.7
sequences recorded in AusTrakka in the past 28-day period.

–

There have been nine sequences from the XDV recombinant lineage (JN.1 and XDE)
identified in the past 28-day period.

Interim Australian Centre for Disease Control

25

Figure 17: Omicron sub-lineage sequences in AusTrakka by sample collection date, showing(A) proportions and (B) count per week*†, Australia, 1 January to 30 June 2024
Variant

1.00

BA.1
BA.2
BA.2.75

0.75

BA.2.86

Propor tion

BA.4
BA.5
EG.5

0.50

JN.1
XBB.1.16
XBB.1.5

0.25

XBB.1.9.1
XBB.2.3
XBC

0.00

XBF
01/24

02/24

03/24

04/24

Date of Collection

05/24

06/24

07/24

Variant

400

BA.1
BA.2
BA.2.75300

BA.2.86

Count

BA.4
BA.5
200

EG.5
JN.1
XBB.1.16
XBB.1.5

100

XBB.1.9.1
XBB.2.3
XBC

0

XBF
01/24

02/24

03/24

04/24

Date of Collection

05/24

06/24

07/24

* Sequences in AusTrakka aggregated by epidemiological week. Sequences are reported based on date of sample collection, not date ofsequencing.
† Proportions in Figure 17A may not be representative when sequence numbers are small; refer to Figure 17B. Data for earlier
epidemiological weeks may change between reporting periods as sequences with older collection dates are uploaded. These numbers
are not equivalent to number of cases, as there are many cases which may not be sequenced. Non-VOI and non-VUM Omicron sublineages have been collapsed into parent lineages BA.1, BA.2, BA.3, BA.4 and BA.5.

Sentinel laboratories, including National Influenza Centres•

In the year to date, there have been 14,497 influenza positive samples received by sentinellaboratories. Of those, influenza A accounted for 96.1% (13,928/14,497) of positive samples
and influenza B accounted for 3.9% (569/14,497) of positive samples (Figure 18).
–

Note, the sum of the number of samples by type may not equal the total number of
positive samples, due to multiple influenza detections in some individual samples.

Interim Australian Centre for Disease Control

26

Figure 18: Proportion of sentinel laboratory tests positive for influenza and total number of
specimens tested by subtype and week of report*, Australia, 1 January to 14 July 2024

*Total number of tests include all specimens that have been tested for influenza, including multiplex panels used to test for SARS-CoV-2.
Testing methodologies vary across jurisdictions and laboratories. Please refer to the Technical Supplement for interpretation of testing
methodologies across jurisdictions and laboratories.

World Health Organization Collaborating Centre (WHOCC) for Reference
and Research on Influenza•

In the year to date, the WHOCC has characterised 1,601 influenza viruses, of which 50.0%(800/1,601) have been influenza A(H1N1), 47.6% (762/1,601) have been influenza A(H3N2),
and 2.4% (39/1,601) have been influenza B/Victoria. In the year to date, there have been no
influenza B/Yamagata viruses characterised by the WHOCC (Table 4).

•

Of the influenza A(H1N1) pdm09 samples tested for neuraminidase inhibitor resistance
0.47% (3/645) demonstrated reduced inhibition to Oseltamivir. Of the influenza A(H3N2)
samples tested for neuraminidase inhibitor resistance, 0.25% (1/408) demonstrated reduced
inhibition to Oseltamivir. None of the influenza B/Victoria samples tested for neuraminidase
inhibitor resistance demonstrated reduced inhibition to Oseltamivir or Zanamivir.

Table 4: Australian influenza viruses typed by the WHOCC for Reference and Research on
Influenza by haemagglutination inhibition assay and jurisdiction*†, 1 January to 14 July 2024
Strain

ACT

NSW

NT

Qld

SA

Tas

Vic

WA

Total

A(H1N1)

43

62

301

41

30

60

203

60

800

A(H3N2)

58

70

287

48

14

30

203

52

762

B/Victoria lineage

7

3

2

4

0

0

18

5

39

B/Yamagata lineage

0

0

0

0

0

0

0

0

0

108

135

590

93

44

90

424

117

1,601

Total

*Viruses tested by the WHOCC for Reference and Research on Influenza are not necessarily a random sample of all those in thecommunity and early-year data may be based on limited samples received. There may be up to a month delay on reporting of samples.
† Jurisdiction indicates the residential location for the individual tested, not the submitting laboratory.

Interim Australian Centre for Disease Control

27

NNDSS•In this fortnight (1 July to 14 July 2024), of the 51,331 influenza notifications reported to the
NNDSS, 97.5% (50,065/51,331) were influenza A(Unsubtyped), 1.1% (557/51,331) were
influenza A(H3N2); 1.0% (513/51,331) were influenza B; and 0.2% (101/51,331) were
influenza A(H1N1). Approximately 0.2% (93/51,331) were influenza untyped. Two
notifications were influenza A&B co-detection (Figure 19).

•

In the year to date, influenza A has accounted for the majority of influenza notifications inmost jurisdictions (Figure 20).

Figure 19: Proportion of influenza notifications to the NNDSS by subtype and week ofdiagnosis, Australia, 1 January to 14 July 2024

Figure 20: Proportion of influenza notifications to the NNDSS by subtype and jurisdiction*,
Australia, 1 January to 14 July 2024

Interim Australian Centre for Disease Control

28

FluCAN•

Since influenza surveillance commenced on 1 April 2024 to date for FluCAN severity
reporting (30 June 2024), 97.5% (1,455/1,493) of patients admitted with influenza to FluCAN
sentinel hospitals have been due to influenza A and 2.5% (38/1,493) of patients admitted to
FluCAN sentinel hospitals have been due to influenza B. Of the hospital admissions due toinfluenza A: 92.0% (1,339/1,455) were A(Unsubtyped), 5.7% (83/1,455) were A(H1N1) and2.3% (33/1,455) were A(H3N2).

•

Since influenza surveillance commenced on 1 April 2024 to date for FluCAN severity
reporting, of the 86 patients who have been admitted directly to intensive care in a FluCAN
sentinel hospital with influenza, 100.0% (86/86) have been due to influenza A. Of theintensive care admissions due to influenza A: 84.9% (73/86) were A(Unsubtyped), 9.3%
(8/86) were A(H1N1) and 5.8% (5/86) were A(H3N2).

Interim Australian Centre for Disease Control

29

6. Vaccine coverage, effectiveness and match
In the present report, data reported on vaccine coverage, effectiveness and match relate toinfluenza vaccinations. COVID-19 and RSV vaccination data will be included in future iterations of
the Australian Respiratory Surveillance Report. Refer to the Technical Supplement – Australian
Respiratory Surveillance Report for further detail on relevant vaccine terminology.

6.1 Vaccine coverage•

It is too early to assess vaccine coverage for the 2024 influenza season.

6.2 Vaccine effectiveness•

It is too early to assess vaccine effectiveness for the 2024 influenza season.

6.3 Vaccine match
WHOCC for Reference and Research on Influenza•

In the year to date, of the 1,601 samples referred to the WHOCC, 98.5% (788/800) of
influenza A(H1N1) isolates, 90.3% (688/762) of influenza A(H3N2) isolates and 100.0%(39/39) of influenza B/Victoria isolates have been antigenically similar to the corresponding
vaccine components.

Australian Influenza Vaccines Composition 2024•

All 2024 southern hemisphere seasonal influenza vaccinations registered for use in Australia
are quadrivalent influenza vaccines.

•

The influenza virus strains included in egg-based quadrivalent influenza vaccines inAustralia in 2024 are:•–

A/Victoria/4897/2022 (H1N1)pdm09-like virus–

A/Thailand/8/2022 (H3N2)-like virus–

B/Austria/1359417/2021 (B/Victoria lineage)-like virus–

B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

The influenza virus strains included in cell-based quadrivalent influenza vaccines in Australia
in 2024 are:–

A/Wisconsin/67/2022 (H1N1)pdm09-like virus–

A/Massachusetts/18/2022 (H3N2)-like virus–

B/Austria/1359417/2021 (B/Victoria lineage)-like virus–

B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

Interim Australian Centre for Disease Control

30