Influenza Activity Surveillance

Surveillance of Influenza activity in Australia & New Zealand

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 the vast majority of people do not get tested for influenza and that there may also be some delays in reporting confirmed influenza cases. Therefore data presented here maybe underestimating influenza activity.

Australia

Commonwealth Department of Health & Ageing

There have been a total of 17,569 laboratory confirmed notifications of Influenza in Australia for 2016, at the end of 26th July.

•    QLD:    5,670
•    NSW:   6,500
•    WA:      1,720 
•    SA:       1,120
•    VIC:      2,115
•    ACT:        170
•    NT:           139
•    TAS:         135

For more national data:  

National Notifiable Diseases Surveillance System

Australian Influenza Surveillance Report                                                             

New South Wales

17 July 2016

The influenza season has started and activity continues to increase steadily, particularly in metropolitan Sydney.

Influenza A(H3N2) is the dominant circulating influenza strain.

Hospital Surveillance – the rate of influenza like illness (ILI) presentations to selected emergency departments decreased this week but remains above the seasonal threshold.

Laboratory surveillance – the proportion of respiratory samples positive for influenza was 14.3%, continuing its steady increase.

Community surveillance – influenza notifications were increased, particularly in metropolitan Sydney local health districts (LHD). General Practice surveillance systems showed moderate levels of ILI activity, similar to the previous week.
Influenza activity has increased in the aged care sector with 11 new respiratory outbreaks reported this week in residential aged care facilities.

National and international influenza surveillance influenza activity is variable across Australia, increasing in some regions, while low and stable in others. Current influenza strains are well matched to the 2016 influenza vaccines. Influenza activity is increasing in other regions in the Southern Hemisphere.

For more information: NSW Health - Infectious Diseases Alert

Queensland

24 July 2016

Recent week onset (18 July to 24 July) there were 421 notifications.  404 (96%) were typed as influenza A and 17 (4%) influenza B. 

40 influenza A have been subtyped: eight (20%) were A(H1N1)pdm09 and 32 (80%) were A/H3N2 

Subtype is unavailable for 364 influenza A cases. 

YTD 2016 (1 January to 24 July) there have been 5,551 notifications.

Influenza A:  4,795 (86%) 

Influenza B:  756 (14%) 

985 influenza A have been subtyped: 564 (57%) were A(H1N1)pdm09 and 421 (43%) were A/H3N2.

Subtype is unavailable for 3,810 influenza A cases. 

An increasing trend in notifications over recent weeks is consistent with early influenza seasonal activity.

The statewide percentage of positive tests (public laboratories) in the most recent week was 7.2%, which is lower than would be expected if transmission of influenza was widespread in the community.

For more information: QLD Health - Preventable Diseases                                                                                                                                                                                                                                                                                                                                                                                                             

South Australia

16 July 2016

Fifty-seven cases of influenza were reported this week with 52 cases being characterised as influenza A and five as influenza B. Cases comprised of 25 males and 32 females, with a median age of 41 years. Eight (14%) notifications were for children aged less than 10 years and 13 (23%) notifications for persons aged 65 years or greater. There have been 1,028 cases of influenza notified year-to-date, compared with 3,521 cases reported for the same period last year.

For more information: Communicable Diseases Control Branch

Tasmania

15 July 2016

This report describes influenza activity in Tasmania during May and June of 2016. Available data over this period indicate: 

Influenza activity remained at the low ‘baseline’ level despite a small increase in testing.

The 2016 winter flu season has not commenced.

Surveillance of influenza-like illness by General Practice and FluTracking continued to indicate minimal activity during this period.

Laboratory tests of nose and throat swabs indicated that other respiratory pathogens were the main
cause of influenza-like illness during May and June.

Since the report of 9 May a further 57 notifications of influenza were received, with 49 relating to influenza detected in specimens collected during May and June. The total number of influenza notifications since the start of 2016 is 122. Notifications of influenza during May and June were similar to March and April. Weekly influenza counts at the end of June remained low and indicated that the winter influenza season had not commenced. For comparison, more influenza had been reported by the end of June 2015 (154 notifications) with the 2015 influenza season in Tasmania having commenced during June 2015.

During May and June Influenza A virus was the most common cause of influenza in Tasmania. To date, additional laboratory typing has been performed on 20 samples of influenza A virus. Fifteen samples were the A(H1N1)pdm09 strain while the remaining five were A(H3N2). The 2016 annual influenza vaccine covers both of these strains.

There have been no outbreaks of influenza in a residential institution reported since the start of 2016.

For more information: Communicable Diseases Prevention - FluTAS

Victoria

24 July 2016

Measures of influenza‐like illness (ILI) from VicSPIN indicate the season is currently slightly above baseline levels.

The ILI rate from the National Home Doctor Service remained above baseline levels in the last week.

The number of notified laboratory confirmed influenza cases for the year to 24 July is 46% lower than the same time in 2015. Of the notified influenza cases, 83% have been type A. VicSPIN detected three positive influenza A(H3N2), two positive influenza A(H1N1)pdm2009 and two influenza A(untyped) during the week.

Overall the data from the influenza and ILI surveillance systems indicate the influenza season remains just at or slightly above baseline levels in Victoria.

The Victorian Department of Health and Human Services received notifications for 168 cases of laboratory confirmed influenza for the week, an increase of 28 cases from the previous week with a slight indication of increasing activity.

A total of 2,148 cases of laboratory confirmed influenza have been notified so far in 2016, 46% fewer than the 3,963 notified for the same period in 2015.

Most (83%) cases in 2016 have been type A, the same percentage (83%) as among last week’s notified cases.

Type A cases (median: 40 years) are generally slightly older than type B cases (median: 37 years).

For more information: Victorian Infectious Diseases Reference Laboratory

Western Australia

17 July 2016

Direct indicators of influenza activity continue to increase, but levels of influenza-like illness remain low for this time of year, perhaps reflecting relatively low levels of non-influenza respiratory virus activity.

ILI presentations to sentinel general practitioners (GPs) increased this week, while presentations to sentinel emergency departments (EDs) decreased slightly, but both remain relatively low for this time of year.

The percent of tests positive for influenza virus and notifications of laboratory-confirmed influenza cases continue to increase.

Hospital admissions in notified influenza cases are below average levels for this time of year.

Influenza A/H1 (10%), influenza A/H3 (39%), and influenza B (51%) are co-circulating, with a relative increase in the proportion of A/H3 cases and decrease in A/H1 cases compared to previous weeks.

For more information: WA Virus WAtch

Nationally

Australian Sentinel Practices Research Network (ASPREN)

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.

19 June 2016

Influenza-Like-Illness levels increased remaining above baseline 

Nationally, ILI notifications decreased slightly over the period with 110 and 129 notifications in weeks 23 and 24 respectively. ILI rates reported in this period were similar with 6 and 8 cases per 1000 consultations in weeks 23 and 24 respectively, compared to 5 and 8 cases per 1000 consultations in weeks 21 and 22 respectively. For the same reporting period in 2015, ILI rates were similar at 7 cases per 1000 consultations. On a state-by-state basis, it is important to note the increased ILI rate in Urban ACT.

(Baseline ILL < 4 in 1000 consultations, Normal 4< ILL rate <24).

For more information: ASPREN 

Flu Tracking

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.

21 July 2016

Low levels of influenza-like illness activity.

This survey was sent on Monday, 18 July 2016 at 01:13 AM and by 09:00 AM, Thursday 21 July we had received 22998 responses (22463 last week) from 13905 people responding for themselves and 9093 household members across Australia.

Across Australia, fever and cough was reported by 2.2% of vaccinated participants and 2.0% of unvaccinated participants. Fever, cough and absence from normal duties was reported by 1.5% of vaccinated participants and 1.3% of unvaccinated participants.

For participants this week, 13761/22998 (59.8 %) have received the seasonal vaccine so far. Of the 4488 participants who identified as working face-to-face with patients, 3579 (79.7%) have received the vaccine.

For more information, or to enrol: Flu Tracking

New Zealand

24 July 2016

During week 29 (18–24 July 2016), influenza activity was very low among consultation-seeking patients nationwide. Influenza activity was also very low among those hospitalised patients in Auckland and Counties Manukau District Health Boards.

Ninety-six patients with influenza-like illness consulted sentinel general practices in 20 DHBs. The weekly ILI incidence was 18.2 per 100 000 patient population, below the seasonal threshold of ILI consultations. The ILI related influenza incidence (adjusted) was 6.7per 100 000 patient population.

During this week, 38 ILI specimens were tested, 14 were positive for influenza viruses.

For more information:  NZ Flu Surveillance