Influenza Activity Surveillance 2019
This report provides a summary of surveillance data collected from around Australia and New Zealand. Regional reporting in some areas ceases when flu activity is low (out of season). Please note that many people do not get tested for influenza and that there may also be some delays in reporting confirmed influenza cases.
Therefore data presented here may be underestimating influenza activity.
Click above for an up to date PDF of Australian Influenza Statistics.
Commonwealth Department of Health & Ageing
There have been a total of 299,211 laboratory confirmed notifications of Influenza in Australia for 2019, at the start of 14 October.
- ACT: 3,920
- NSW: 112,113
- NT: 1,435
- QLD: 65,941
- SA: 25,534
- TAS: 2,893
- VIC: 64,729
- WA: 22,646
For more national data: National Notifiable Diseases Surveillance System
Week ending 6 October 2019
- Influenza activity continues to decrease across NSW, consistent with the end of the winter influenza season in most areas and a return to inter-seasonal activity levels.
- Respiratory presentations to NSW emergency departments continue to decrease and are within the usual range for this period.
- Both influenza A and B strains continue to decline and the overall influenza positive test rate is approaching inter-seasonal levels.
Summary for this reporting week:
Hospital surveillance – ILI presentations to EDs decreased and are within the usual range for this time of year.
Laboratory surveillance – overall respiratory testing and the influenza laboratory test positive rate (8.4%) both declined.
Community surveillance – influenza activity decreased across the State. One outbreak was reported from a residential aged care facility.
Death surveillance – eleven influenza deaths were reported. People who die with influenza may have other underlying illnesses, and surveillance captures only a proportion of people who die from influenza.
National surveillance – declining influenza activity; overall clinical severity rated as low.
2020 Southern Hemisphere influenza vaccine announced:
WHO influenza vaccine strain recommendations – Northern Hemisphere, 2019-20
The WHO Consultation on the Composition of Influenza Vaccines for Use in the 2019-20 Northern Hemisphere Influenza Season was held in Beijing on 18-20 February 2019.
From this meeting it was recommended that egg based quadrivalent vaccines for use in the 2019-2020 northern hemisphere influenza season contain the following:
- an A/Brisbane/02/2018 (H1N1)pdm09-like virus;
- an A/Kansas/14/2017 (H3N2)-like virus;
- a B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage); and
- a B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage).
It was also recommended that the influenza B virus component of trivalent vaccines for use in the 2019-2020 northern hemisphere influenza season should be a B/Colorado/06/2017-like virus of the B/Victoria/2/87-lineage.
In light of recent changes in the proportions of genetically and antigenically diverse A(H3N2) viruses, the recommendation for the A(H3N2) component was announced on 21 March. More details about the most recent influenza vaccine recommendations can be found at: http://www.who.int/influenza/vaccines/virus/en/
For more information: NSW Health – Infectious Diseases Alert
Week ending 6 October 2019
Summary of the year so far:
YTD positive tests for influenza: 65,680
Influenza A: 53,706 [A(H1N1) 963; A(H3N2) 2,835; subtype unavailable 49,908]
Influenza B: 11,974 [Victoria 190; Yamagata 14; Lineage Unavailable 11,770]
YTD hospitalisations: 2,980
YTD percentage of tests positive: 19.6%
For the week 30 September – 6 October:
Influenza notifications: 705
Influenza A: 478 [A(H1N1) 5; A(H3N2) 10; Subtype unavailable 463]
Influenza B: 227 [Victoria 1; Yamagata 0; lineage unavailable 226]
Influenza hospitalisations for the week: 27
Percentage of test positive for the week: 10.7%
For more information: QLD Health – Preventable Diseases
29 September – 5 October 2019
From 1 January to 5 October 2019, there were 25,397 notifications of influenza reported to the Communicable Disease Control Branch, compared to 3,297 cases reported for the same period last year.
Of these notifications:
- 13,969 were in females and 11,428 were in males
- The age range is <1 year – 105 years, with a median age of 31 years
- 21,625 cases (85%) were due to influenza A virus and 3,772 cases (15%) were due to influenza B virus
- 2,282 cases (9%) were hospital inpatients
- One hundred and five cases (0.41%) were reported to have died from influenza virus infection (age range 15 – 100 years).
For more information: Communicable Diseases Control Branch
August 2019 update
This surveillance report describes influenza activity in Tasmania during the period 1 January to 31 August 2019.
- Community syndromic surveillance in Tasmanian suggested influenza-like illness activity that was stable during August 2019 and decreased compared to during July.
- Laboratory-confirmed influenza notifications peaked at 180 cases during the third week of August (week 33). Notifications during August were similar for this time of year compared to previous years.
- Influenza testing increased by 5 per cent during August compared to during July. Testing since the start of 2019 has been 2.5 times the amount of testing conducted during the same period of 2018.
- The proportion of tests positive for influenza peaked during the third week of August.
- Two hundred and fifteen patients have been admitted to the Royal Hobart Hospital with influenza between 1 April and 30 August 2019.
- Influenza activity across Australia during August 2019 was reported to be lower than the average of previous years, following an apparent peak in activity in early July. Clinical severity for the season to date across Australia, as measured through the proportion of patients admitted directly to intensive care, and deaths attributed to influenza, is low.
Notifications of laboratory-confirmed Influenza to Public Health Services
There were 560 cases of influenza notified in Tasmania during August 2019. Between 2015 and 2018 an average of 478 cases of influenza were notified during the month of August.
Since 1 January 2019 a total of 2 491 cases of influenza have been notified.
During August weekly influenza case numbers increased to a peak of 180 cases before decreasing to 112 cases
Five per cent more influenza tests were conducted in Tasmania during August 2019 than during July: 2,220 tests compared to 2,120 tests during July. The highest number of influenza tests occurred during the third week of August (587 tests).
Since the start of 2019 influenza testing conducted by Tasmanian laboratories has been significantly greater than previous years. Between 1 January and 31 August 2019 a total of 11 374 influenza PCR tests were reported by laboratories: 2.5 times the testing conducted during the same period of 2018 (4,538 tests).
Proportion of tests positive for influenza
The weekly proportion of tests positive for influenza peaked during the third week of August (28 per cent) before declining to 21 per cent at the end of the month.
During 2014 to 2018, on average, 25 per cent of weekly influenza tests were positive during August (range one to 49 per cent positive).
For more information: Communicable Diseases Prevention – FluTAS
Week ending 6 October 2019
Overview: The 2019 influenza season so far
Influenza-like illness (ILI) is well below the average threshold this week.
The total ILI proportion measured by VicSPIN this week is similar to last week and similar to the same time in 2018, but lower than for the same time in 2017.
The number of notified cases of laboratory confirmed influenza is over nine times higher than by the same time in 2018 and almost 1.5 times higher than in 2017.
The majority of notified cases over the season have been type A (77%), and type A cases are older than type B cases.
The ratio of type A to B has shifted in the last four weeks, with type A decreasing to 54% of notifications and type B comprising 46%.
Nine swabs were received from VicSPIN this week, of which 0% (0 swabs) were positive for influenza. The average for the season is 33%.
To date, influenza A(H3) was co-detected with A(H1N1)pdm09 in one case. In eight additional cases, influenza was co-detected with another respiratory virus.
For more information: Victorian Infectious Diseases Reference Laboratory or Victorian State Health Department
Week ending 6 October 2019
INFLUENZA AND INFLUENZA-LIKE ILLNESSES (ILI)
Indicators of influenza activity were below levels usually reported during this time of year in WA.
ILI activity at sentinel GPs remained low in the past week.
ILI presentations at sentinel EDs increased in the past week, while admissions remained stable.
PathWest influenza detections and test percent positivity were at low levels for this time of year.
Influenza A accounted for 64% of influenza detections at PathWest in the past week, comprising 13% influenza A/H1N1, 13% influenza A/H3N2 and 38% influenza A/not subtyped. Influenza B accounted for 38% of detections.
For more information: WA Virus WAtch
ASPREN is a national syndromic surveillance program co-ordinated by the Discipline of General Practice at the University of Adelaide and The Royal Australian College of General Practitioners. One of the conditions under surveillance is influenza like illness (ILI). General practitioners participating in the ASPREN program contribute data on the proportion of consultations which are ILI related.
12 – 25 August 2019
- Influenza-like-illness levels are decreasing
- 99 Cases of influenza have been detected in this reporting period: 76 x Influenza A and 23 x Influenza B
- 32% Influenza positivity during the reporting period
- 1070 Cases of influenza have been detected this year: 873 x Influenza A and 197 x Influenza B
Reports were received from 367 reporters from 8 states and territories during the reporting period. During weeks 33 and 34 reporters saw a total of 54,892 patients.
Nationally, ILI notifications decreased during the period with 596 notifications being reported in weeks 33—34. ILI rates reported in this period increased to 14 and 12 cases per 1000 consultations (weighted) in weeks 33 and 34 respectively. This was higher than the previous fortnight where rates were 12 cases per 1000 consultations. For the same reporting period in 2018, ILI rates were lower at 6 and 7 cases per 1000 consultations for weeks 33 and 34.
(Baseline ILL < 3 & 4 in 1000 consultations, Normal 4< ILL rate <24).
For more information: ASPREN
FluTracking is a pilot online health surveillance system which aims to detect epidemics of influenza. It is a joint initiative of The University of Newcastle, Hunter New England Area Health Service (NSW Health) and Hunter Medical Research Institute. Participation is voluntary and involves the completion of a weekly online survey during the influenza season. Data are collected on basic demographics, symptoms of ILI and absenteeism.
Week ending 6 October 2019
This week influenza-like illness activity is at the same level as the 5 year average.
36,283 participants this week
(Data received up to 09:00 AM, Thursday 10 October)
Fever and cough: 1.5% this week (same as 5 year average)
Flu Symptom Activity by vaccination status:
0.2% lower fever and cough in unvaccinated group this weekInfluenza-like illness Severity:
26.5% of participants with fever and cough sought medical advice this week
Vaccination rates: 78% overall
For more information, or to enrol: Flu Tracking
Week ending 29 September 2019
In the last week of seasonal influenza surveillance for the year, indicators of influenza-like illness (ILI) activity in the community have remained low. Both ILI activity and the rate of people presenting to general practices (GP) with ILI who test positive for influenza virus are below the baseline level. Influenza A(H3N2) and B/Victoria viruses are co-circulating in the community and influenza A viruses are still predominating in hospitals. Virology reports indicate there has been a mutation in the influenza B/Victoria virus strain circulating in New Zealand during the 2019 season. This is expected to reduce the 2019 seasonal vaccine effectiveness for this influenza virus strain.
National indicators of community influenza-like illness (ILI) activity have mostly continued to decrease over the past few weeks.
Indicators of severity remain below seasonal baseline levels. Activity in Intensive Care Units is low.
For more information: NZ Flu Surveillance