Report No. 40
Week ending 8 October 2010
A print friendly version of this report is available as a PDF (229 KB)The Department of Health and Ageing acknowledges the providers of the many sources of data used in this report and greatly appreciates their contribution.
Key Indicators
Influenza activity and severity in the community is monitored using the following indicators and surveillance systems:| Is the situation changing? | Indicated by trends in:
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| How severe is the disease, and is severity changing? | Indicated by trends in:
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| Is the virus changing? | Indicated by trends in:
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Summary
- Levels of influenza-like illness (ILI) in the community increased through some surveillance systems this reporting period (ASPREN and WA EDs), while others (Flutracking and the National Health Call Centre Network) showed a decrease in ILI. Local, regional and widespread activity was reported within jurisdictions. The number of laboratory confirmed notifications continued to decrease nationally and in all states and territories.
- There were 339 laboratory confirmed notifications of influenza during this reporting period, including 222 pandemic (H1N1) 2009 cases. Notifications of laboratory confirmed influenza were highest in South Australia.
- Results from sentinel laboratory surveillance systems for this reporting period show that 17% of the respiratory tests conducted over this period were positive for influenza, which is the same as the last two reporting periods. In 2010, a total of 1,184 specimens have been positive for influenza
(of 13,457 specimens tested), of which 67% were pandemic (H1N1) 2009, 9% were A/H3N2, 21% were influenza B and 3% were influenza A untyped. - In recent weeks there has been an increase in the proportion of influenza type B in Western Australia.
- As at 8 October 2010, there have been 9,084 confirmed cases of influenza entered into the National Notifiable Diseases Surveillance System (NNDSS) in 2010. A total of 43,022 confirmed cases of pandemic (H1N1) 2009 have occurred in Australia since May 2009.
- Sentinel hospitals reported a slight increase in the number of influenza associated hospitalisations compared to the previous reporting period, with 15 admissions, including 11 for pandemic (H1N1) 2009. ANZICS reported an decrease in ICU admissions for influenza this reporting period, with six admissions.
- The WHO has advised that the world is no longer in phase 6 of influenza pandemic alert, and has moved into the post pandemic period.
1. Influenza activity in Australia
Geographic spread of influenza and ILI – Jurisdictional Surveillance
In the fortnight ending 1 October 2010, influenza and ILI activity as reported by state and territory Health Departments was ‘sporadic’ in ACT, ‘regional’ in NT and ‘widespread’ in NSW, SA, WA, QLD and VIC (Figure 1). Definitions of these activity levels are provided in the Data Considerations section of this report.Figure 1. Map of influenza and ILI activity, by state and territory, during fortnight ending 1 October 2010
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Influenza-Like Illness
Sentinel General Practice Surveillance
In the week ending 3 October 2010, the national ILI consultation rate to sentinel GPs was approximately 17 cases per 1,000 consultations (Figure 2), an increase to the rate reported in the previous week (13 cases per 1,000 consultations). The consultation rate is above levels seen at this time in 2009.Figure 2. Weekly rate of ILI reported from GP ILI surveillance systems from 1 January 2007 to 8 Ocotber 2010*
* Delays in the reporting of data may cause data to change retrospectively. As data from the VIDRL surveillance system is combined with ASPREN data for 2010, rates may not be directly comparable across 2007, 2008 and 2009.
SOURCE: ASPREN.
Of the ASPREN ILI specimens collected in the week ending 8 October 2010, 11% were positive for influenza, of which they were all pandemic (H1N1) 2009 (Table 1). Please note the results of ASPREN ILI laboratory respiratory viral tests do not currently include WA.
Table 1. ASPREN ILI consultations laboratory respiratory viral tests that were positive for influenza for the week ending 8 October 2010.
 | ASPREN – national |
|---|---|
| Total specimens tested | 54 |
| Positive Influenza A | 6 |
| Pandemic (H1N1) 2009 | 6 |
| Seasonal A/H1N1 | 0 |
| Seasonal A/H3N2 | 0 |
| Influenza A untyped | 0 |
| Positive Influenza B | 0 |
| Positive – type unknown | 0 |
WA Emergency Departments
Respiratory viral presentations reported in WA EDs have plateau in the most recent week. An overall upward trend in ILI related ED presentations has occurred since the beginning of 2010 (Figure 3). In the week ending 3 October 2010 there were 678 respiratory viral presentations, (including 34 admissions), similar to the number of presentations in the previous reporting week (671).Figure 3. Number of respiratory viral presentations to WA EDs from 1 January 2007 to 3 October 2010 by week
Source: WA ‘Virus Watch’ Report
NSW Emergency Departments
In the week ending 8 October 2010, ILI presentations to NSW EDs increased to 2.1 per 1,000 presentations, but remain at low levels and are slightly higher than expected for this time of year. (Figure 4). ILI presentations were mainly for mild illness and there were seven admissions to hospital during this period. In September 2010, there were 334 presentations with ILI, a rate of 1.8 per 1,000 presentations, with a total of 24 admissions to hospital. This is slightly higher than the previous month (19 admissions). The number of ILI presentations in 2010 continues to be well below seasonal levels observed in 2007 and 2009.Top of Page
Figure 4: ILI presentations to NSW EDs from 2007-2010, by week
Source: NSW Health ‘Influenza Weekly Epidemiology Report
Flutracking
Flutracking is a national online system for collecting data on ILI in the community. In the week ending 10 October 2010, Flutracking reported that ILI activity levels decreased and returned to baseline across Australia (Figure 5).Figure 5. Rate of ILI symptoms among Flutracking participants by week, from week ending 30 May 2010 to week ending 10 October 2010
Source: Flutracking Interim Weekly Report
National Health Call Centre Network
The number of calls to the National Health Call Centre Network (NHCCN) in this reporting period was lower than in previous reporting periods (Figure 6), and the percentage of total calls decreased slightly.Call numbers cannot be compared between early 2009 and early 2010, as not all call centres were online in early 2009. The difference in the number of operating call centres accounts for the apparent increase in recorded ILI calls (and baseline levels) between the two years.
Figure 6. Number of calls to the NHCCN related to ILI and percentage of total calls, Australia, 1 January 2009 to 8 October 2010
Note: national data does not include QLD and VIC
Source: NHCCN data
Absenteeism
Due to system changes, absenteeism data has not been updated since July 2010. Absenteeism data will not be included in this report until provision of the data resumes.Top of Page
Laboratory confirmed influenza
Sentinel Laboratory Surveillance
Results from sentinel laboratory surveillance systems for this reporting period show that 17% (112/664) of the respiratory tests conducted over this period were positive for influenza, which is unchanged from the last two reporting periods (Figure 7).Figure 7. Total number of specimens tested by sentinel laboratories, and proportion positive, 1 January 2010 to 8 October 2010, by week
SOURCE: Sentinel laboratory data from ASPREN, NSW NIC, WA NIC, VIC NIC & TAS Labs
Sentinel laboratories reported 112 specimens positive for influenza during this reporting period, of which 59 were pandemic (H1N1) 2009, 16 were A/H3N2, 3 were influenza A (untyped) and 34 were influenza B (Table 2).
Table 2. Laboratory respiratory tests that tested positive for influenza, week ending 8 October 2010
| WA NIC | NT (reported by WA NIC) | VIDRL | TAS | NSW NIC |
|---|---|---|---|---|---|
| Total specimens tested | 384 | n/a | 130 | 34 | 116 |
| Positive Influenza A | 57 | 3 | 9 | 4 | 5 |
| Pandemic (H1N1) 2009 | 39 | 2 | 9 | 4 | 5 |
| Seasonal A/H1N1 | 0 | 0 | 0 | 0 | 0 |
| Seasonal A/H3N2 | 15 | 1 | 0 | 0 | 0 |
| Influenza A untyped | 3 | 0 | 0 | 0 | 0 |
| Positive Influenza B | 33 | 0 | 0 | 1 | 0 |
Figure 8. Percentage of specimens tested by sentinel laboratories influenza positive, 1 January 2010 to 8 October 2010, by subtype
SOURCE: Sentinel laboratory data from ASPREN, NSW NIC, WA NIC, VIC NIC & TAS Labs
Laboratory Confirmed Cases Notified to Health Departments
During this reporting period there were 339 influenza notifications reported to NNDSS (205 in SA, 91 in Qld, 24 in WA, 9 in NSW, 5 in NT, 3 in Vic and 2 in Tas). They included 222 cases of pandemic (H1N1) 2009, 94 of influenza A (untyped), 17 of influenza B and 6 of untyped (Figure 9). The number of laboratory confirmed notifications continued to decrease this reporting period, across all jurisdictions.In recent weeks there has been an increase in the proportion of influenza type B in Western Australia.
There have been 9,084 confirmed cases of influenza of all types diagnosed during 2010 up to
8 October (Figure 9). Of these, 5,386 (59%) have been sub-typed as pandemic (H1N1) 2009 influenza, 2,827 (31%) as influenza A (untyped), 162 (2%) as A/H3N2 and 10 (<1%) as type A&B. A further 552 (6%) have been characterised as influenza type B and 147 (2%) were untyped.
Figure 9. Laboratory confirmed cases of influenza in Australia, 1 January 2005 to 8 October 2010
Source: NetEpi (2009; NSW 2010) and NNDSS (2010)
Note: The scale in this figure has been limited to 1600 notifications per week to allow for comparison
between 2010 and previous years. In 2009, notifications peaked at approximately 8,300 in Week 30.
As at 8 October 2010, the number of laboratory confirmed cases of influenza was 3,062 in SA, 1,960 in QLD, 1,486 in VIC, 1,131 in WA and 1,039 in NSW. There were a further 253 cases in the NT, 76 cases in the ACT and 77 cases in TAS (Figure 10). For a breakdown of trends by state and territory, see Figure 11.
Figure 10. Laboratory confirmed cases of influenza in Australia, 1 January to 8 October 2010, by state, by week.
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Figure 11. State breakdowns of laboratory confirmed cases on influenza, 1 January to 8 October 2010, by week
In 2010, the distribution of influenza notifications has been relatively consistent across all age groups with an overall slight downward trend with increasing age. This distribution is reasonably similar to 2008, except in the 0-4 and the 74 and over age groups, in which sharp increases occurred in 2008 (Figure 12). In 2009 the distribution of influenza notifications tended to occur in persons aged less than 55 years, with substantially higher rates observed in persons aged less than 30 years, compared to older age groups.
Figure 12. Laboratory confirmed cases of influenza (pandemic (H1N1) 2009 and seasonal) in Australia, 1 January 2008 to 8 October 2010, by age group
Source: NNDSS and NetEpi (NSW).
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2. Influenza severity to 1 October 20101
Pandemic (H1N1) 2009
While pandemic (H1N1) 2009 is generally considered a mild disease at the community level, it has had serious consequences for some people. Figures of hospitalisations, ICU admissions and deaths are currently used as indicators of the severity of the disease in Australia (Table 3).
Pandemic (H1N1) data for 2009 are being finalised through cleaning and validation processes. It is possible that these processes will result in some changes in the data presented here. Validated data will be progressively reported as these steps are completed.
Since the first case of pandemic (H1N1) 2009 in Australia in May 2009, there have been a total of 43,022 confirmed cases of pandemic (H1N1) 2009 in Australia as at 8 October 2010. Of these, 37,636 cases were reported in 2009 and 5,386 cases were reported in 2010. A total of 211 pandemic influenza-associated deaths have been reported, 20 of which occurred in 2010.
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1 Note that while the analysis of severity is on-going, updates are presented as required when there are significant changes detected. With the current low levels of pandemic (H1N1) 2009 influenza activity in Australia it is anticipated that the indicators of pandemic associated severity will not vary significantly.
Table 3. Summary of severity indicators of pandemic (H1N1) in Australia, 2009 and 2010 (up to 8 October 2010)
| 2009# | 2010a | |||||
|---|---|---|---|---|---|---|
| Confirmed pandemic (H1N1) 2009 cases | Hospitalised cases | ICU cases | Deathsb | Confirmed (H1N1) 2010 cases | Deathsb |
| Total number | 37,636 | 13% (4,992/37,636) confirmed cases) | 14% (681/4,992 hospitalisations) | 191 | 5,386 | 20 |
| Crude rate per 100,000 population | 172.1 | 22.8 | 3.1 | 0.9 | 24.6 | n/a |
| Median age (years) | 21 | 31 | 44 | 53 | 23 | 52 |
| Females | 51% (19,139/37,636) | 51% (2,528/4,992) | 53% (364/681) | 44% | 51.5% (2,776/5,386) | 40% (8/20) |
| Vulnerable groups (Indigenous persons, pregnant women & individuals with at least 1 co-morbidity) | n/a | 58% (2,892/4,992) | 74% (504/681) | 67% | n/a | 80% (16/20) |
| Indigenous people~ | 11% (3,877/34,750) | 20% (808/4,048) | 19% (102/533) | 13% | 7% (138/1,982) | 0% |
| Pregnant women* | n/a | 27% (287/1,056 hospitalised females aged 15-44 years) | 16% (47/289) hospitalised pregnant women) | 4% | n/a | 0% |
| Cases with at least 1 co-morbidity | n/a | 46% (2,303/4,992) | 67% (457/681) | 62% | n/a | 80% (16/20) |
#Data are extracted from a number of sources depending on the availability of information. Figures used in the analysis have been provided in parentheses. Data are not always complete for each summarised figure.
aData for 2009 from NetEpi, data for 2010 from NNDSS and NetEpi (NSW).
bThe number of deaths is likely to be under-reported and representative of hospital related death notifications only.
n/a - No data collected or available.
*Includes women in the post-partum period.
~The denominator for this row is the number of confirmed cases for which Indigenous status is known. In 2010, 3,404 cases had Indigenous status unknown.
Influenza Hospitalisations
Influenza Complications Alert Network (FluCAN)
The Influenza Complications Alert Network (FluCAN) reported an increase in the number of influenza associated hospitalisations in the week ending 8 October 2010, with 11 pandemic (H1N1) 2009 hospitalisations and three influenza A not subtyped hospitalisations from sentinel hospitals. For the period of 1 March to 8 October 2010, FluCAN has reported a total of 258 influenza associated hospitalisations (Figure 13). Of these, 211 were associated with pandemic (H1N1) 2009, including 57 with ICU admission.Figure 13. Number of influenza hospitalisations, sentinel hospitals, Australia, 1 March to 8 October 2010
Source: Influenza Complications Alert Network (FluCAN). Data from 15 sentinel hospitals from all jurisdictions.
Table 4. FluCAN sentinel hospitalisation severity indicator summary 1 March to 8 October 2010
| Pandemic (H1N1) 2009 | Seasonal | Total Influenza | ||||||
|---|---|---|---|---|---|---|---|---|---|
All hospitalised | ICU cases | Deaths | All hospitalised | ICU cases | Deaths | All hospitalised | ICU cases | Deaths | |
| ICU proportion of all hospitalised | 26% | | 24% | | 26% | | |||
| Median age (years) | 35 | 38 | 36 | 36 | 36 | n/a | 35 | 35 | 38 |
| Females | 52% | 45% | 67% | 53% | 36% | 0% | 52% | 38% | 67% |
| Total of vulnerable groups (Indigenous, pregnant & individuals with at least 1 co-morbidity) | 73% | 80% | 100% | 70% | 100% | 0% | 73% | 83% | 100% |
| Indigenous people | 4% | 2% | 0% | 0% | 0% | 0% | 4% | 2% | 0% |
| Pregnant women% of all admission | 7% | 13% | 0% | 6% | 9% | 0% | 7% | 13% | 0% |
| % of women of child bearing age (15-49years) | 14% | 28% | 0% | 12% | 25% | 0% | 14% | 24% | 0% |
| Cases with at least 1 co-morbidity | 69% | 80% | 100% | 66% | 91% | 0% | 69% | 82% | 100% |
Australian Paediatric Surveillance Unit (APSU)
A survey of admissions to Intensive Care Units (ICUs) of children aged 15 years and under due to influenza complications is conducted through the Australian Paediatric Surveillance Unit (APSU). Details of admissions are reported on a weekly basis.For the week ending 5 October 2010, there were four cases of severe influenza complications in children reported to the APSU. This is more than the previous reporting week (three cases). Since 1 July 2010, 30 hospitalisations have been reported, 13 of which were associated with pandemic (H1N1) 2009. Five of those cases were admitted to ICU. Nine cases were associated with Influenza A (not further subtyped), and one case was associated with influenza B. Four of the cases associated with pandemic (H1N1) 2009 had an underlying chronic condition.
Intensive care admissions
The Australian and New Zealand Intensive Care Society (ANZICS) has reported a total of 198 ICU admissions for influenza in 2010, six of which occurred during this reporting period. Of these, 141 were associated with pandemic (H1N1) 2009, 16 with influenza A (not subtyped), 5 with seasonal A/H3N2, 31 with seasonal H1N1 (these may be pandemic cases, yet to be confirmed) (Figure 14).Of the 141 pandemic (H1N1) 2009 ICU admissions in 2010, 60 had known co-morbidities and the median age at admission was 43 years (range 2-80).
Figure 14. Number of ICU admissions for influenza in Australia, 1 January to 8 October 2010
Source: Australian and New Zealand Intensive Care Society (ANZICS) data base
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Deaths associated with influenza and pneumonia
Nationally reported pandemic (H1N1) 2009 deaths
In 2010, 20 pandemic influenza related deaths have been notified to the NNDSS. The deaths occurred in late May, July, August and September, with a median age of 52 years. Sixteen of the deaths were reported as having underlying risk factors.NSW
Death registration data show that for the week ending 8 October 2010, there were 124 pneumonia or influenza associated deaths per 1,000 deaths in NSW, which is below the seasonal threshold for this period of 143 per 1,000 deaths (Figure 15).NSW death registration data cross-matched with laboratory cases of influenza show 21 people with laboratory confirmed influenza have died up to 29 September 2010. Seventeen of the cases had multiple comorbidities and were aged 50 years and over.1
Figure 15. Rate of deaths classified as influenza and pneumonia from the NSW Registered Death Certificates, 2005 to 8 October 2010
Source: NSW ‘Influenza Monthly Epidemiology Report’
3. Virology
Typing and antigenic characterisation - WHO Collaborating Centre for Reference & Research on Influenza (WHO CC) in Melbourne
From 1 January to 10 October 2010, there were 1038 Australian influenza isolates subtyped by the WHO CC with the majority of isolates typed as pandemic (H1N1) 2009 (Table 5).Table 5. Typing of influenza isolates from the WHO Collaborating Centre, from 1 January 2010 to 10 October 2010
| Type/Subtype | ACT | NSW | NT | QLD | SA | TAS | VIC | WA | TOTAL |
|---|---|---|---|---|---|---|---|---|---|
| A(H1N1) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Pandemic (H1N1) 2009 | 16 | 33 | 136 | 273 | 142 | 1 | 233 | 105 | 939 |
| A(H3N2) | 2 | 2 | 0 | 14 | 0 | 3 | 9 | 17 | 47 |
| B | 0 | 3 | 0 | 10 | 5 | 0 | 18 | 16 | 52 |
| Total | 18 | 38 | 136 | 297 | 147 | 4 | 260 | 138 | 1038 |
SOURCE: WHO CC
Please note: There may be up to a month delay on reporting of samples.
Isolates tested by the WHO CC are not necessarily a random sample of all those in the community, hence proportions of pandemic (H1N1) 2009 to seasonal are not representative of the proportions circulating.
Antigenic characterisation of 642 pandemic (H1N1) 2009 isolates has shown 575 to be the A/California/7/2009-like strain and 6 a low reactor version of this strain. Antigenic characterisation of 31 type A/H3N2 isolates has shown 24 to be the A/Perth/16/2009-like and 7 to be the A/Perth/16/2009-like low reactor versions of the strain. One isolate was antigenically characterised as a low-reactor version of B/Florida/4/2006-like, 28 were characterised as B/Brisbane/60/2008-like and 1 a low reactor version of this strain.
Antiviral Resistance
The WHO Collaborating Centre in Melbourne has reported that from 1 January 2010 to 10 October 2010, no isolates (out of 749 tested) have shown resistance to oseltamivir or zanamivir by enzyme inhibition assay (EIA) and two pandemic (H1N1) 2009 isolates (out of 41 tested) have shown the H275Y mutation known to confer resistance to oseltamivir.2011 Southern Hemisphere Vaccine
The WHO has recommended that the composition of vaccines for use in the 2011 influenza season (southern hemisphere winter) contain the following:- an A/California/7/2009 (H1N1)-like virus;
- an A/Perth/16/2009 (H3N2)-like virus;
- a B/Brisbane/60/2008-like virus2
4. International Influenza Surveillance
The WHO has advised that the world is no longer in phase 6 of influenza pandemic alert, and has moved into the post pandemic period.3 As at 1 August 2010 there have been over 18,449 deaths associated with pandemic (H1N1) 2009 influenza worldwide since April 20094.The WHO has reported that influenza activity is decreasing in most parts of the Southern Hemisphere and the season has not appeared to have started in the Northern Hemisphere. Influenza A/H3N2 is now the predominant influenza virus worldwide after several weeks of increasing detections, although many areas still have active transmission of pandemic (H1N1) 2009. Most of the influenza A/H3N2 viruses detected are A/Perth/16/2009-like, which is the strain included in the seasonal vaccine for the Northern and Southern Hemispheres.4
In New Zealand, the ILI consultation rate peaked in early August and has now returned to below baseline levels. Of the influenza viruses identified through sentinel and non-sentinel swab testing in the past week, 81% were pandemic (H1N1) 2009.influenza5
5. Data considerations
The information in this report is reliant on the surveillance sources available to the Department of Health and Ageing. As access to sources increase and improve, this report will be refined and additional information will be included.This report aims to increase awareness of pandemic (H1N1) 2009 and seasonal influenza in Australia by providing an analysis of the various surveillance data sources throughout Australia. While every care has been taken in preparing this report, the Commonwealth does not accept liability for any injury or loss or damage arising from the use of, or reliance upon, the content of the report. Delays in the reporting of data may cause data to change retrospectively. For further details about information contained in this report please contact the Influenza Team through flu@health.gov.au.
On 17 June 2009 Australia commenced the transition to a new response phase called PROTECT, in which laboratory testing is directed towards people with moderate or severe illness; those more vulnerable to severe illness; and those in institutional settings. This means that the number of confirmed cases does not reflect how many people in the community have acquired pandemic (H1N1) 2009 infection.
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Geographic spread of influenza and ILI – Jurisdictional Surveillance
Jurisdictions report activity levels (in line with the definitions below) on a fortnightly basis, based on laboratory-confirmed notifications, various syndromic surveillance systems, outbreak reporting and rumour surveillance.| Activity level | Definitions: |
|---|---|
| No activity | No influenza or ILI activity |
| Syndromic only | an increase in syndromic surveillance systems with no laboratory confirmed cases |
| Sporadic | small numbers of laboratory-confirmed influenza cases or a single laboratory-confirmed influenza outbreak during the reporting period, but no increase in cases in syndromic surveillance systems |
| Local | outbreaks of influenza or increases in cases in syndromic surveillance systems and recent laboratory-confirmed influenza in a single region of the state |
| Regional | outbreaks of influenza or increases in cases in syndromic surveillance systems and a recent laboratory confirmed influenza in at least two but less than half the regions of the state |
| Widespread | outbreaks of influenza or increases in cases in syndromic surveillance systems and recent laboratory-confirmed influenza in at least half the regions of the state. |
Sentinel General Practice Surveillance
The Australian Sentinel Practices Research Network (ASPREN) has Sentinel GPs who report ILI presentation rates in NSW, NT, SA, ACT, VIC, QLD, TAS and WA. As jurisdictions joined ASPREN at different times and the number of GPs reporting has changed over time, the representativeness of ASPREN data in 2010 may be different from that of previous years. ASPREN data and VIDRL influenza surveillance data are sent to the Surveillance Branch on a weekly basis. Further information on Sentinel GPs’ Influenza Surveillance and ASPREN activities are available at www.dmac.adelaide.edu.au/aspren.Sentinel ED data
WA - ED surveillance data are extracted from the ‘Virus Watch’ Report. This report is provided weekly. The Western Australia Influenza Surveillance Program collects data from eight Perth EDs. NSW - ED surveillance data are extracted from the ‘Weekly Influenza Report, NSW’. The New South Wales Influenza Surveillance Program collects data from 56 EDs across New South Wales.FluTracking
FluTracking is a project of the University of Newcastle, the Hunter New England Area Health Service and the Hunter Medical Research Institute. FluTracking is an online health surveillance system to detect epidemics of influenza. It involves participants from around Australia completing a simple online weekly survey, which collects data on the rate of ILI symptoms in communities. Data have been provided weekly and have been presented in this report to show the pattern of self reported ILI in the community over the 2009 season.Further information on FluTracking is available at www.flutracking.net/index.html.
National Health Call Centre Network
A national organisation provides call centre data for calls relating to ILI or influenza. Data are provided daily and are collated weekly and have been presented in this report to show the pattern of calls to this Call Centre over the 2009 and 2010 season. Data is available for all jurisdictions other than QLD and VIC.Absenteeism
A national organisation provides data on the number of employees who have been on sick leave for a continuous period of more than three days. These data are not influenza or ILI specific and absenteeism may be a result of other illnesses.Sentinel Laboratory Surveillance data
Laboratory testing data are provided weekly directly from PathWest (WA), VIDRL (VIC), ICPMR (NSW), sentinel Tasmanian laboratories, and ASPREN (national).National Notifiable Diseases Surveillance System (NNDSS)
Laboratory confirmed influenza (all types) is notifiable in all jurisdictions in Australia. Confirmed cases of influenza are notified through NNDSS by all jurisdictions except NSW. NSW data are sourced from NetEpi.NetEpi
In 2009, NetEpi, a web-based outbreak case reporting system for pandemic (H1N1) 2009, was used as the primary source of enhanced data on confirmed cases, hospitalisations and ICU admissions in all jurisdictions. In 2010, only data for NSW are sourced from NetEpi.Analyses of Australian cases are based on the diagnosis date, which is the earliest of the onset date, specimen date or notification date.
Data Analysis
Analysis of confirmed influenza cases is conducted on combined NetEpi and NNDSS data. Analysis of morbidity (hospitalisations and ICU admissions) and mortality data in 2009 has been conducted on combined NetEpi and QLD hospitalisation data.FluCAN
The Influenza Complications Network (FluCAN) collects detailed clinical information on all hospitalised cases of influenza and pneumonia from a sample of 15 sentinel hospitals across Australia. The data for this reporting period are sourced only from 14 hospitals.APSU
The Australian Paediatric Surveillance Unit collects clinical information on hospitalised cases of children aged 15 years and under with complications due to influenza infection. Approximately 1300 (80% of total) Paediatric clinicians registered with the Paediatrics and Child Health Division of the Royal College of Physicians, respond to APSU report cards. These report cards seek information regarding hospitalisations relating to 12 diseases or conditions, including influenza.Australian and New Zealand Intensive Care Society data (ANZICS data)
The Australian and New Zealand Intensive Care Society provide data from a `near real time` registry of patients admitted to Australian ICUs. This documents the key factors influencing mortality, as well as the need for hospitalisation and mechanical ventilation. Information collected includes person characteristics and information on relevant co-morbidities, nature of the clinical syndrome associated with pandemic (H1N1) 2009, major therapeutic interventions from which organ failure outcomes can be imputed, vaccination status and vital status at time of ICU discharge and hospital discharge.WHO Collaborating Centre for Reference & Research on Influenza (WHO CC)
Data are provided weekly to the Surveillance Branch from the WHO CC.Deaths associated with influenza and pneumonia
Nationally reported pandemic (H1N1) 2009 deaths are notified by jurisdictions to the Commonwealth Department of Health and Ageing as they occur.NSW influenza and pneumonia deaths data are collected from the NSW Registry of Births, Deaths and Marriages. Figure 14 is extracted from the ‘Weekly Influenza Report, NSW’
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6. References
1 NSW Influenza Monthly Epidemiology Report, September 2010. Available from http://www.health.nsw.gov.au/publichealth/infectious/reports/influenza_report_august.asp Accessed 14 October 2010.2 World Health Organisation Global Alert and Response: Influenza. Recommended composition of influenza virus vaccines for use in the 2011 southern hemisphere influenza season. Available from http://www.who.int/csr/disease/influenza/recommendations2011south/en/index.html Accessed 1 October 2010.
3 World Health Organisation virtual press conference, 10 August 2010. Available from http://www.who.int/en/ Accessed 11 August 2010.
4 WHO Influenza update – 8 October 2010. Available from http://www.who.int/csr/don/en/ Accessed 14 October 2010.
5 New Zealand Weekly Influenza Update: 27 September - 3 October 2010. Available from http://www.surv.esr.cri.nz/virology/influenza_weekly_update.php Accessed 14 October 2010.