Influenza Activity Surveillance 2020
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 from the NNDSS.
National Notifiable Diseases Surveillance System (NNDSS)
There have been a total of 21,208 laboratory confirmed notifications of Influenza in Australia for 2020, at the start of 2nd November.
- ACT: 195
- NSW: 7,205
- NT: 283
- QLD: 6,005
- SA: 1,526
- TAS: 163
- VIC: 4,639
- WA: 1,192
For more national data: National Notifiable Diseases Surveillance System (NNDSS)
The weekly flu report has currently been suspended due to the COVID response, however weekly influenza information is available in the COVID-19 weekly surveillance report.
March Influenza Report 2020
- Influenza activity was low for this time of year and has continued to decrease throughout the month.
- Influenza A(H1N1) remained the predominant circulating influenza strain.
- Respiratory presentations to NSW emergency departments decreased but were above the historical range for this time of year.
- Influenza activity continue to decrease throughout March and remained within inter-seasonal levels.
- Influenza A strains, particularly influenza A (H1N1), remained predominant over influenza B strains, with an overall influenza percent positive rate of 2.1%.
- Respiratory testing was increased overall, likely reflecting the on-going COVID-19 outbreak.
- Influenza activity was low across all local health districts. Rates were highest in the Hunter New England LHD.
- Presentations to emergency departments for respiratory illnesses and influenza-like illness were above the usual historical ranges for this time of year.
- Three influenza outbreaks were reported from residential aged care facilities, all caused by influenza A.
For more information: NSW Health – Infectious Diseases Alert
Week ending 25 October 2020
Recent week 19 – 25 October 2020:
0 x Influenza A notifications for the week:
0 x A (H1N1);
0 x A (H3N2);
0 x subtype unavailable.
0 x Influenza B notifications for the week:
0 x Victoria;
0 x Yamagata;
0 x lineage unavailable.
Total influenza notifications for the week: 0
All influenza notifications to date: 6,002
This includes: Influenza A: 5,288 and Influenza B: 711
For more information: QLD Health – Preventable Diseases
Week 18 – 24 October 2020
No cases of influenza were reported this week. There have been 1,577 cases of influenza notified year-to-date, compared with 25,888 cases reported for the same period last year.
For more information: Communicable Diseases Control Branch
Week ending 25 October 2020
Number of laboratory confirmed flu notifications for this week: 1
Total influenza cases YTD: 163
[141 influenza A and 22 influenza B]
FluTAS 2020 Report 6
Public Health Services produce the fluTAS Report to provide information about the level of influenza (flu) in Tasmania. Several surveillance data sources are used to obtain measures of influenza activity in the community. This surveillance report describes influenza activity in Tasmania during the period 1 January 2020 to 27 September 2020 (week 39).
It is important to note that due to the COVID-19 epidemic in Australia, data reported from the various influenza surveillance systems may not represent an accurate reflection of influenza activity. Results should be interpreted with caution, especially where comparisons are made to previous influenza seasons. Interpretation of 2020 influenza activity data should take into account, but is not limited to, the impact of social distancing measures, likely changes in health seeking behaviour of the community including access to alternative streams of acute respiratory infection specific health services, and focussed testing for COVID-19 response activities. Current COVID-19 related public health measures and the community’s adherence to public health messages are also likely having an effect on transmission of acute respiratory infections, including influenza.
2020 summary to date: 1 January to 27 September
- There have been 161 laboratory-confirmed influenza notifications in Tasmania to date.
- There were relatively high notifications at the beginning of the year compared to previous years before decreasing in mid-March and remaining low.
- This decline in notifications coincided with the physical distancing policies, implemented by the Commonwealth and Tasmanian Governments during March 2020 in response to the COVID-19 pandemic.
- A similar decline in influenza notifications has been observed nationally.
- Influenza A has been the predominant circulating influenza virus with 140 notifications (87 per cent).
- 9 044 polymerase chain reaction (PCR) tests for influenza have been conducted with only two per cent of these PCR tests being positive for influenza.
Notifications of laboratory-confirmed influenza to Public Health Services
Influenza notifications are based on positive laboratory tests. Many people with influenza-like illness choose not to attend medical care or are not tested when they attend. Notifications therefore represent a small proportion of the total influenza cases in the community.
From 1 January 2020 to 27 September 2020 (week 39), Public Health Services received 161 laboratory confirmed notifications of influenza. This is 91 per cent lower than the 4-year (2016-2019) average of 1 793 notifications received over the same time period.
Monthly influenza case numbers were relatively high during January and February of 2020 compared to previous years before decreasing in mid-March and remaining low (Figure 1). This decline coincided with the social distancing policies, implemented by the Commonwealth and Tasmanian Governments during March 2020 in response to the COVID-19 pandemic. Since the last FluTAS Report (for the period ending 30 August 2020, week 35) no laboratory-confirmed influenza notifications have been received by Public Health Services in Tasmania. A similar decline and pattern of low influenza notifications has been observed nationally.
There has been an increased focus on laboratory testing this year in response to the COVID-19 pandemic with 9 044 polymerase chain reaction (PCR) tests conducted between 1 January and 27 September 2020. PCR testing for influenza increased dramatically in March and peaked in early May with 648 tests conducted in week 19. PCR testing has been declining gradually since week 20 with 633 PCR tests being conducted during the four-week period since the last FluTAS Report (for the period ending 30 August 2020, week 35).
Proportion of tests positive for influenza
The average weekly proportion of tests positive for influenza so far this year is only two per cent, ranging from zero to 14 per cent. The percentage of positive tests peaked in week 2 at 14 per cent and week 5 at 13 per cent before gradually declining to zero per cent in week 14. There have been no PCR tests positive for influenza in Tasmania since March 29 (week 13).
For the full report, use the link below.
For more information: Communicable Diseases Prevention – FluTAS
Week ending 25 October 2020
- Influenza-like illness (ILI) is lower than last week and remains well below the average activity threshold.
- The total ILI proportion measured by VicSPIN is 0 ILIs per 1000 patients seen.
- The number of notified cases of laboratory confirmed influenza is 93% lower than the number notified by the same time in 2019.
- The majority of notified cases over the season have been type A (88.5%), and type A cases are older than type B cases.
- Zero swabs were received from VicSPIN this week.
For more information: Victorian Infectious Diseases Reference Laboratory or Victorian State Health Department
Week ending 25 October 2020
It is important to note that the influenza and ILI surveillance systems in WA have been impacted by the COVID-19 pandemic. Therefore interpretation of 2020 influenza and ILI activity should be done with caution and needs to take into account the effects of changes in health seeking behaviour including accessing alternate health services such as telehealth, focused testing for COVID-19 at COVID-19 clinics or specific acute respiratory infection clinics and the impact of physical distancing measures, Influenza and influenza-like illnesses (ILI).
INFLUENZA AND INFLUENZA-LIKE ILLNESSES (ILI)
- Indicators of influenza activity remain at or below interseasonal levels.
- ILI activity at sentinel GPs and EDs remains below levels usually seen at this time of year.
- There were no positive influenza samples reported by PathWest in the past week.
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.
5 – 18 October 2020
Influenza-like-illness levels remain steady below baseline levels.
- 0 Cases of influenza have been detected in this reporting period:
0 x Influenza A
0 x Influenza B
- 0% Influenza positivity during the reporting period.
- 22 Cases of influenza have been detected this year:
20 x Influenza A
2 x Influenza B
Reports were received from 277 reporters from 8 states and territories during the reporting period. During weeks 41 and 42 reporters saw a total of 45,857 patients.
Nationally, ILI notifications slightly increased during the period with 29 notifications being reported in weeks 41—42. ILI rates reported in this period remained steady at 1 case per 1000 consultations (weighted). This was similar to the previous fortnight where rates were 1 case per 1000 consultations in weeks 39 and 40. For the same reporting period in 2019, ILI rates were higher at 3 cases per 1000 consultations for weeks 41 and 42.
(Baseline ILL < 3 & 4 in 1000 consultations, Normal 4< ILL rate <24).
For more information: ASPREN
FluTracking is an 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 25 October 2020
This week influenza-like illness activity is low.
(Data received up to 09:00AM, Thursday 29 October)
Influenza-like illness activity:
Fever and cough: 0.5% this week (flu-like illness activity is historically low)
Influenza-like illness severity:
51.2% of participants with fever and cough sought medical advice this week
49,233 participants (65,339 last week)
Vaccination rates: 83.3% overall
For more information, or to enrol: Flu Tracking
Sentinel General Practice-Based influenza-like-illness (ILI) Surveillance
General practice-based ILI surveillance methods have changed in 2020 due to the COVID-19 response, limiting interpretability for influenza ILI surveillance. Collection of specimens commenced on 2 June 2020 and stopped on 27 September 2020. During this period there were 229 specimens collected from patients presenting to general practices with ILI symptoms, 0 (0%) of which were influenza positive. Of the tested swabs: 20 were enterovirus positive; 76 were rhinovirus positive (one swab had both enterovirus and rhinovirus detected); 1 was human metapneumovirus positive; and 1 was adenovirus positive. For the surveillance period last year, 1617 specimens were tested of which 919 (56.8%) were influenza positive.
HealthLine and HealthStat
ILI-related HealthLine call trends have been heavily impacted by the COVID-19 response, people experiencing symptoms of respiratory illness are advised to call HealthLine for assessment and advice. General practice ILI consultations reported through HealthStat practices have also been heavily impacted by the COVID-19 response with changes in patient flow and health seeking behaviour. This limits interpretability for ILI surveillance in 2020.
Both ILI-related call rates to HealthLine and ILI consultations rates reported by HealthStat increased dramatically in March as national COVID-19 case notifications increased followed by a sharp decline in April. ILI-related rates reported from both of the surveillance systems increased again in early June, following the easing of social distancing restrictions and the start of the winter season followed by a decline starting in late June and continuing through July.
There was a third increase in ILI-related call rates to HealthLine in early August with a decline in the following three weeks. This trend was expected given the identification of COVID-19 cases in the Auckland region and subsequent changes in alert levels. Similarly, ILI consultation rates reported by HealthStat increased in early August but declined in the following three weeks.
ILI-related call rates to HealthLine have fluctuated throughout September, October with an increase in rates in the week ending 23 October 2020. This increase was most evident among children aged <1 year and was observed in most DHBs.
In contrast, ILI consultation rates reported by HealthStat, overall and by age group and DHB, did not change significantly throughout September, October. There has been a small increase in rates in the week ending 23 October 2020. This slight increase was most evident in those aged 0-4 years and in Counties Manukau DHB.
For more information: NZ Flu Surveillance