Influenza and pneumonia hospitalisations

Males, 65+, 2010-11
2915.8Males, 65+, 2009-10
2781.5Males, 65+, 2008-09
2982.4Males, 65+, 2007-08
3155.7Males, 65+, 2006-07
2859.4Males, 65+, 2005-06
2755.4Males, 65+, 2004-05
3017.5Males, 65+, 2003-04
3021.8Males, 65+, 2002-03
3089.8Males, 65+, 2001-02
3032.3Males, 65+, 2000-01
3240.8Males, 65+, 1999-00
3331.3Males, 65+, 1998-99
3635Males, 65+, 1997-98
3705.4Males, 65+, 1996-97
3285.3Males, 65+, 1995-96
3072.4Males, 65+, 1994-95
3036.6Males, 65+, 1993-94
2665.2Males, 65+, 1992-93
2775.4Males, All ages, 2010-11
683.2Males, All ages, 2009-10
674.8Males, All ages, 2008-09
681.3Males, All ages, 2007-08
714.6Males, All ages, 2006-07
654.2Males, All ages, 2005-06
675.2Males, All ages, 2004-05
710.8Males, All ages, 2003-04
748.8Males, All ages, 2002-03
732Males, All ages, 2001-02
719Males, All ages, 2000-01
741Males, All ages, 1999-00
756Males, All ages, 1998-99
862.8Males, All ages, 1997-98
849.9Males, All ages, 1996-97
749.4Males, All ages, 1995-96
678Males, All ages, 1994-95
647.7Males, All ages, 1993-94
603Males, All ages, 1992-93
665.4Females, 65+, 2010-11
1957.5Females, 65+, 2009-10
1800.3Females, 65+, 2008-09
1970.1Females, 65+, 2007-08
1967.6Females, 65+, 2006-07
1739.9Females, 65+, 2005-06
1832.8Females, 65+, 2004-05
1908.4Females, 65+, 2003-04
1953.7Females, 65+, 2002-03
1949.2Females, 65+, 2001-02
1774.5Females, 65+, 2000-01
1996.2Females, 65+, 1999-00
2083.6Females, 65+, 1998-99
2156.4Females, 65+, 1997-98
2296.7Females, 65+, 1996-97
1880.8Females, 65+, 1995-96
1701.2Females, 65+, 1994-95
1684.4Females, 65+, 1993-94
1466.8Females, 65+, 1992-93
1511Females, All ages, 2010-11
548.6Females, All ages, 2009-10
527.6Females, All ages, 2008-09
527.5Females, All ages, 2007-08
541.9Females, All ages, 2006-07
476Females, All ages, 2005-06
513.2Females, All ages, 2004-05
526.3Females, All ages, 2003-04
560.4Females, All ages, 2002-03
543.2Females, All ages, 2001-02
512.6Females, All ages, 2000-01
540Females, All ages, 1999-00
568Females, All ages, 1998-99
625.4Females, All ages, 1997-98
640.4Females, All ages, 1996-97
535.6Females, All ages, 1995-96
458.4Females, All ages, 1994-95
445Females, All ages, 1993-94
402.2Females, All ages, 1992-93
453.2
 
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Supporting Text
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Notes
Commentary

NSW Admitted Patient Data Collection and ABS population estimates (SAPHaRI). Centre for Epidemiology and Evidence, NSW Ministry of Health.

Only NSW residents are included. Figures are based on where a person resides, not where they are treated. Hospital separations were classified using ICD-9-CM up to 1997-98 and ICD-10-AM from 1998-99 onwards. Rates were age-adjusted using the Australian population as at 30 June 2001. Numbers for the two latest years include an estimate of the small number of hospitalisations of NSW residents in interstate public hospitals, data for which were unavailable at the time of production.

Influenza and pneumonia are a group of acute respiratory infections that can be very severe and, in persons at high risk, lead to death. They are usually presented together as influenza can lead to pneumonia and, in most cases of hospitalisation and death from pneumonia, the responsible organism is not identified. Each year, 75-85 % of all hospitalisations for influenza and pneumonia are due to 'unspecified pneumonia'.

Severe virus-related complications of influenza require hospitalisation and threaten life most frequently in the very young and elderly (children under 1 year old and persons over 65) and among persons with chronic heart or, especially, lung conditions. Appropriate antibacterial therapy decreases the mortality rate from secondary bacterial pneumonia.

In 2009, the WHO recommended that ICD-10-AM J09 code be used to cover influenza A/H1N1 (initially called ‘swine flu’) responsible for the pandemic 2009 and the code has been added to the set of codes relevant here.

Select the rows below to view more detail on a method

NSW Admitted Patient Data Collection

The NSW Admitted Patient Data Collection (APDC) or Inpatient Statistics Collection (ISC) is a census of all services for admitted patients provided by public hospitals, public psychiatric hospitals, public multi-purpose services, private hospitals and private day procedure centres in NSW. The APDC is a financial year collection from 1 July through to 30 June of the following year. The information it contains is provided by patients, health service providers, and the hospital's administration. The information reported includes patient demographics, source of referral to the service, service referred to on separation, diagnoses, procedures, and external causes.

For this report, the APDC was accessed via SAPHaRI. THe APDC data is still called the 'ISC' data on SAPHaRI to maintain consistency in naming of SAS datasets.

The APDC includes data on hospital admissions of NSW residents which occurred in hospitals interstate. The only exception to this is that data from interstate hospitals for the year 2006-07 were not yet available when the data was analysed. This may affect analyses and has a greater effect on rates for areas closer to an interstate boundary. Analyses by Health Area and analyses involving uncommon diagnoses or procedures are particularly affected. Therefore, ab estimate was made of interstate admissions for 2006-07. The estimate was based on admissions for the preceding three years (2003-04 to 2005-2006). The first step was to determine the proportion of total admissions for NSW residents in the preceding three years which were at interstate hospitals. That proportion was used to multiply the number of admissions at hospitals in NSW in 2006-07, to obtain the estimate of the number of admissions expected to have occurred at interstate hospitals. The estimates were calculated for each age-sex stratum. Where hospitalisations were further categorised, for example by diagnosis, geographical place of residence or country of birth, the imputation procedure was carried out separately for each category, thus accounting for the uneven distribution of interstate hospital admissions.

From 1 July 1998, inpatient data on SAPHaRI (formerly HOIST) have been for episodes of care in hospital. Episodes of care end with the discharge, transfer, or death of a patient. A new episode of care may also start when the service category for an admitted patient is altered, as a result of a change in the on-going clinical care requirements for that patient during the one episode of accommodation in a single facility. APDC data on SAPHaRI up to 30 June 1998 were for periods of stay in hospital. A period of stay in hospital ends with the discharge, transfer, or death of a patient, and may consist of multiple episodes of care. The change from 'period of stay' to 'episode of care' causes a small increase in the apparent number of admissions.

The reason for a hospital admission is coded at the time of separation (discharge, transfer or death). Since 1 July 1998, coding has been according to the 10th revision of the International Classification of Diseases, Australian Modification ICD-10-AM. Updated ICD-10 coding manuals have been published by the National Centre for Classification in Health every two years since 1998. Prior to this, coding was according to the 9th revision of the International Classification of Diseases, Clinical Modification (ICD-9-CM), using the Australian version (National Coding Centre, 1996) from July 1995 and the US version prior to that.

Since 1 July 1998, procedures carried out during a patient's stay have been coded according to the MBS-Extended Procedure Classification, published as Volume 3 and Volume 4 of the 10th revision of the International Classification of Diseases, Australian Modification (ICD-10-AM). Updated ICD-10 coding manuals have been published by the National Centre for Classification in Health every two years since 1998. Prior to this, procedures were coded according to the 9th revision of the International Classification of Diseases, Clinical Modification (ICD-9-CM), using the Australian version (National Coding Centre, 1996) from July 1995 and the US version prior to that.

The numbers of diagnosis and procedure codes that may be recorded, at the time of separation, have varied over time, and are currently as follows:

· principal diagnosis (the principal reason for admission);

· up to 54 other diagnoses;

· up to 50 procedures and procedure blocks;

· up to eight external cause codes for injury and poisoning.

· up to three codes for place of occurrence injury or poisoning.

· up to three codes for activity at time of injury or poisoning.

Mapping tables between ICD-9-CM and ICD-10-AM disease codes, produced by the National Centre for Classification in Health, were used extensively to obtain the most appropriate match for individual codes between the two classification systems. The ICD-10-AM and ICD-9-CM codes used for each indicator are included in the disease and procedure codes section of the appendix.


Methods: Hospitalisation

1. Hospital statistics in NSW

All NSW public hospitals, public psychiatric hospitals, public multi-purpose services, private hospitals and private day procedure centres in NSW report data on patients admitted for care to the NSW Ministry of Health. Patient separations from developmental disability institutions and private nursing homes are not included. These reported data, from about 400 different facilities in NSW, are called the NSW Admitted Patient Data Collection (APDC).

The collection also includes data relating to NSW residents hospitalised interstate (see below in Imputation for more details) and in Commonwealth Department of Veterans’ Affairs facilities.

Each reporting facility has its own Patient Administration System (PAS), there are five types of these in NSW: HNMA Millenium (administered by Cerner), WinPAS, iPM (I-Soft), HOSPAS (legacy system being phased out and replaced with other systems) and ISCOS, which is the Inpatient Statistics Collection On-line System used by private hospitals. Data from the PAS systems are loaded into the Health Information Exchange (HIE) in a standard format. The HIE is the data warehouse for the whole NSW health system maintained by the NSW Ministry of Health which is accessed by authorised staff across the health system and in the NSW Ministry of Health. Data from the HIE are extracted and loaded onto the Secure Analytics for Population Health Research and Intelligence (SAPHaRI) warehouse, administered by the Centre for Epidemiology and Evidence and used for this report.

2. The Admitted Patient Data Collection and this report

The Admitted Patient Data Collection (APDC) is a census of all inpatients treated in NSW and includes data on NSW residents treated in other states.  The APDC was, up to 2002, known as the Inpatient Statistics Collection. The APDC contains approximately 70 variables and is based on a financial year cycle beginning on 1 July and ending on 30 June of the following year.

The APDC data used in this report are the SAPHaRI (Secure Analytics for Population Health Research and Intelligence) data warehouse, maintained by the Centre for Epidemiology and Evidence. The APDC data is extracted from the Health Information Exchange (HIE) and undergoes a quality assurance and standardisation process before being loaded onto SAPHaRI in a SAS dataset format. 

Further information on the APDC and SAPHaRI is available in this report in Methods tab under The Admitted Patient Data Collection title.

3. Use of selected variables of APDC in this report

3.1 Principal diagnosis and additional diagnoses coded to the ICD-9-CM and ICD-10-AM

Each hospital episode in the APDC is described by a principal diagnosis and additional diagnoses, which are coded using the International Statistical Classification of Diseases and Related Health Problems:  ICD-9-CM (up to June 1998) and ICD-10-AM (from July 1998 onwards). Please refer to a separate Methods section on Principal and additional diagnoses for a detailed discussion (this section accompanies selected indicators that include principal and additional diagnoses, for example diabetes hospitalisations).

In this report the count of hospitalisations for a condition is based mainly on principal diagnosis. If an indicator contains analysis of data in additional diagnosis fields as well ('comorbidities'), this is clearly stated in the title of an indicator and in the Notes. The Notes specify how many additional diagnosis fields were included in the analysis. Another exception is the topic of injury and poisoning where the count is based on ‘external cause of injury’. See Methods for injury and poisoning indicators.

The number of additional diagnoses that are included in the hospital records is restricted to conditions which fulfil several requirements, including direct relevance to the treatment and management of the principal diagnosis. This ensures that only the most resource intensive or clinically relevant conditions are listed for that hospitalisation rather than all comorbidities that a patient may have. Data on additional hospital diagnoses cannot therefore be used to estimate the prevalence of a condition in the community.

3.2 Procedures coded to Australian Classification of Health Interventions

Procedures performed in Australian hospitals are coded in medical records using the Australian Classification of Health Interventions (ACHI) published by the National Centre for Classification in Health.  This classification is based on the Commonwealth Medicare Benefits Schedule and relates to anatomy rather than surgical specialty.

Up to 30 June 1998, the ICD-9-CM Procedure Classification was used in Australia. This was based on WHO Surgical procedures (edition 5) and was not revised and carried beyond 1998 by the WHO due to the rapid advancements in the field of procedures  (National Coding Centre 1996).

On 1 July 1998, both the ACHI and the ICD-10-AM were introduced in NSW. They are revised every two years.  The ICD-10 is the WHO classification but the AM suffix stands for Australian Modification, which adds detail necessary to describe practice in Australian hospitals. The ICD-10-AM is fully compatible with ICD-10 (NCCH 2006).

Up to the fourth edition of ICD-10-AM in 2004, the ACHI was published as a part of the ICD manuals (volume 3 and 4), from the fifth edition in 2006 the titles of the ACHI publication emphasise that this is a classification independent from the ICD.

Both ICD-9-CM Procedure Classification (up to and including 1997-98) and Australian Classification of Health Interventions (from 1998-99 onwards) are used in this report.

3.3 Episode of care based count of hospitalisations

The count of hospitalisations in this report is based on an episode of care from 1 July 1998 (ISC EOC datasets on SAPHaRI). A patient can have several episodes of care during one hospital stay, that is, between the formal admission and the formal discharge (separation) from hospital.    

The episode of care is defined by a service category. An episode of care starts when the hospital stay starts or when the service category changes. There are ten service categories: acute care, rehabilitation care, palliative care, maintenance care, newborn care, other care, geriatric evaluation and management, psychogeriatric care, organ procurement-posthumous and hospital boarder. 

A new episode of care starts also when a patient is on leave from hospital: more than 4 days away in any hospital and more than 10 days away in psychiatric hospitals.

3.4 Overnight and day-only hospital stays are included

Both overnight and day-only hospitalisations are included in this report, unlike in the national reporting on hospital statistics (AIHW Health services series no. 40. Cat. no. HSE 107 2011), where day-only hospitalisations are not included.

The only exceptions are the count and rate of hospitalisation for falls in elderly (persons aged 65 years and over) in NSW, where day-only hospitalisations are excluded from the key indicator reports in NSW. NSW performance reporting of hospitalisations for falls in elderly in NSW includes overnight (and longer) hospitalisations. However, in this report, an analysis of day-only hospitalisations and the total of overnight and day-only hospitalisations are also included in the relevant indicator for comparison and completeness.

3.5 Full census of hospitalisations from 1993-94 and sampling factor prior to 1993-94

In 1993-94 the APDC (then known as the Inpatient Statistics Collection) was a fully enumerated survey (that is a census) for the first time. Datasets containing financial years earlier than 1993-94 are based on estimates from a sample of all inpatient data in some hospitals, partiularly in rural areas, and their use in analysis requires the inclusion of a sampling factor weighting variable. 

3.6 Separation date determines the year of hospitalisation

The main record file of the hospital stay for a patient is created or completed on separation from hospital when all relevant documentation is made available to hospital medical record departments. Consequently, the main reason for hospitalisation (principal diagnosis) completed at separation, may be different from the admitting diagnosis. The hospitalisation is counted in the year when the separation took place even if the hospitalisation period occurred predominantly in the previous financial year. For example a patient discharged on 1 July after a 4 week hospital stay would be counted as hospitalised in the new financial year.

3.7 Imputation of interstate hospitalisations in the last year of data

At the time when the NSW Ministry of Health completes the Admitted Patient Data Collection for the previous financial year, data on hospitalisations of NSW residents in other states are usually not available and so interstate hospitalisations for the latest year is always ‘imputed’ from the previous three years in this report. This imputation process estimates the number of hospitalisations occurring in other states for each diagnosis in previous years and adds these numbers to the latest year of data. When the actual data become available, the number and rates for the affected year are re-calculated. 

3.8 Summary of major changes in the hospital data on SAPHaRI

1988-89:           Hospital data included from the Inpatients Statistics Collection (ISC) counted on the basis of a "period of stay" in hospital (ie multiple episodes of care).  ICD-9-CM used and sampling from some hospitals (requiring a sampling factor for weighting numbers in these hospitals). 

1993-94:             Admitted Patient Data Collection (APDC) is a fully enumerated census of hospitalisations.

1998-99 onwards:             APDC starts to be counted as episodes of care. ICD-10-AM replaces ICD-9-CM; and Australian Classification of Health Interventions replaces ICD-9-CM Procedure Classification. 

Imputation for interstate hospitalisations: The latest year of data (number and rates) are ‘imputed’ for missing interstate hospitalisations for NSW residents. The actual number of interstate hospitalisations is included when available. 

4. Differences between figures published by the AIHW and the NSW Ministry of Health and other institutions

4.1 Differences in publication schedules

The APDC dataset is continuously updated because it is not uncommon to receive additional records or additional information on records already supplied well after the close of a financial year. Consequently data on hospitalisations in NSW from different sources, such as this report and the AIHW report, will always differ slightly due to different publication schedules.

4.2 Imputation of interstate hospitalisations in the latest year of data

In this report imputation methods are used to estimate the number of hospitalisations of NSW residents occurring elsewhere in Australia in the latest year due to a lag in receiving this information (see above). Over some periods of time two last years of data need to be imputed. Refer to Notes in the indicator for confirmation how many years are imputed at the time. Estimates may vary slightly from the estimates in other releases of this report or other reports because of the imputation. The actual number of interstate hospitalisations is included when relevant. 

4.3 Definition of hospitalisation

Both overnight and day-only hospitalisations are included in this report, unlike in the national reporting on hospital statistics, where only overnight hospitalisations are included (AIHW Health services series no. 40. Cat. no. HSE 107 2011).

4.4 Different projected populations

For the calculation of rates, the NSW Ministry of Health uses population projections based on the population projections  prepared by the NSW Department of Planning. Refer to Methods in Population-Demography topic for further information on projected populations and other issues mentioned here. The rates in this report are expressed as a number per 100,000 population.

Rates published by the Australian Institute of Health and Welfare may be expressed differently (per 1,000 or 10,000 population) and use different projected population estimates for NSW. The population estimates, which are not projected, are likely to be the same, as these are based on the estimated residential populations published by the ABS.

5. Other datasets holding data on activity in hospitals

The APDC datasets contain information on inpatient hospital activity. Emergency department data and Outpatient activity data are also available to report on hospital activity.

6. References

Australian Institute of Health and Welfare. Australian hospital statistics 2009–10. Health services series no. 40. Cat. no. HSE 107. Canberra: AIHW, 2011. Available at http://www.aihw.gov.au/publication-detail/?id=10737418863 (Cited on April 2011).

National Centre for Classification in Health. The International statistical classification of diseases and related health problems, 10th Revision, Australian Modification (ICD-10-AM). Australian Coding Standards. Sydney: NCCH, 2006.

National Coding Centre. The Australian version of the International Classification of Diseases, 9th revision, clinical modification (ICD-9-CM). Sydney: University of Sydney, 1996.

 


Select the rows below to view more detail on a code

Codes: Influenza and pneumonia

The International Statistical Classification of Diseases and Related Health Problems

National Centre for Classification in Health, Australia; CM - Clinical Modification; AM - Australian Modification

DescriptionICD-9 & ICD-9-CMICD-10 & ICD-10-AMComments
Influenza and pneumonia 480-487 J09-J18 All records are included, NSW residents only, all ages.

 

In 2009, the WHO recommended that ICD-10-AM J09 code be used to cover influenza A/H1N1 (initially called ‘swine flu’) responsible for the pandemic 2009 and the code has been added to the set of codes above.


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Related Indicators

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Respiratory diseases hospitalisations

Number and rate by disease type,sex, Local Health District, Medicare Local, remoteness from service centres and year
 
Key points: Communicable diseases

Vaccine Preventable Diseases

In 2013 there were:

• 9 invasive Haemophilus influenzae type b notifications, of which five were in children aged less than 5 years

• 2,338 pertussis notifications, the lowest since 2007 when a highly sensitive test became widely used. There were no infant pertussis deaths.

• 34 measles notifications, of which 16 were imported from overseas, 8 were linked to imported cases, and one case was acquired in Victoria. 9 locally acquired measles cases were reported with no known source of infection. 8 cases were notified from the Sydney Local Health District. The largest single outbreak, of 6 cases, was in Northern NSW Local Health District associated with an imported case at a school.

• 46 meningococcal disease notifications, a dramatic decrease from 65 in 2012. Of these, 26 were due to serogroup B (57%), 8 were due to serogroup Y (17%), 6 were due to serogroup W135 (13%), 3 were due to serogroup C (7%), and 3 were of an unknown serogroup (7%). Of the 3 cases of meningococcal C disease, 2 were in adults aged over 50 years, and 1 was reported in a teenager who was vaccinated against meningococcal C disease (the 3rd vaccine failure identified in NSW since vaccine introduction in 2003).

• 90 mumps notifications, a decrease from the 105 reported in 2012. The highest notifications were in metropolitan areas and in under-vaccinated persons aged 15–19 years (15 cases), followed by those aged 30–34 years (12 cases).

• 12 rubella notifications, including a cluster in the North Coast Local Health District (6 cases).

• 469 invasive pneumococcal disease notifications, a marked decrease compared with 581 in 2012. In children less than 5 years, 65% of notifications were due to non-vaccine related serotypes; serotype 19A was the predominant vaccine related serotype in this age group.

 

Blood Borne Viruses

In 2013 there were:

• 357 cases of newly diagnosed HIV infection, a 13% decrease compared with 2012 (409 cases). Of these 357 cases, 278 (78%) were reported as men who have sex with men (MSM).  This compares with 330 MSM related new diagnoses in 2012, a 16% decrease in the notifications in this major risk group. 40% of patients newly diagnosed with HIV infection in 2013 had evidence of early stage infection, a lesser proportion than that reported for new diagnoses in 2012 (47%) and 2011 (50%).  Overall HIV testing increased by 6% in 2013 compared to 2012, with almost 450,000 tests performed.

• 2,478 notifications of unspecified hepatitis B, an 8% increase compared with 2012 (2,288 cases) and about the same as the average of the previous five years (2,458 cases). 54% of cases were males. Hepatitis B is notified as “unspecified” when the time of infection is unknown (most notifications) or is known to be longer than two years prior to diagnosis.

• 34 newly acquired hepatitis B case notifications, an increase of 17% compared with 2012 (29 cases), but similar to the average of the previous five years (n=35). 65% of cases were males.  Newly acquired hepatitis B is notified when there is evidence that the infection was acquired within two years of diagnosis.

• 3.462 notifications of unspecified hepatitis C, 7% higher than in 2012 (3,245 cases) but 2% lower than the average of the previous five years (3,519 cases). Sixty-six percent of cases were males.

• 44 newly acquired hepatitis C case notifications, 14% lower than in 2012 (51 cases) but 10% higher than the average of the previous five years (40 cases). 55% of cases were males and 50% were aged between 15 and 29 years. Newly acquired hepatitis C is notified when there is evidence that the infection was acquired within two years of diagnosis.

 

Sexually Transmissible Infections

In 2013 there were:

• 20,821 chlamydia case notifications, a decrease of 2% compared with 2012 (21,305 cases). 55% of cases were females and 56% were aged between 15 and 24 years.

• 4,243 gonorrhoea case notifications, an increase of 3% compared with 2012 (4,127 cases). 82% of cases were males and 42% were aged between 20 and 29 years.

• 624 infectious syphilis case notifications, a 21% increase compared with 2012 (514 cases). Almost all cases (95%) were men.  The most commonly affected age groups were between 30 and 39 years (30%) and 40 and 49 years (29%).

• 27 lymphogranuloma venereum (LGV) case notifications, a decline from 29 in 2012. All cases were men. Almost half of the cases (48%) were aged between 25 and 34 years, and a further 44% were between 35 and 44 years. The number of LGV notifications has decreased each year since 2010 following an outbreak early in that year.

 

Enteric Diseases

In 2013 there were:

• 7,598 enteric disease case notifications, a 9% increase compared with the average annual count for the previous five years, but 1% lower than the total enteric disease notifications for 2012

• 3,438 salmonellosis case notifications, a 16% increase compared with 2012 and 13% higher than  the average annual count for the previous five years

• 39 outbreaks of probable foodborne disease affecting 417 people, a decrease compared with 61 outbreaks affecting 662 people in 2012

• 687 outbreaks of probable viral gastroenteritis in institutions affecting 10,069 people, a decrease compared with 803 notifications affecting 13,842 people in 2012

• 9 point-source outbreaks of Salmonella Typhimurium infection affecting 109 people, most likely associated with the consumption of sauces, smoothies, and desserts prepared with raw eggs

• 29 listeriosis cases. There was a cluster of three listeriosis cases in NSW public hospitals in April 2013 associated with consumption of chocolate profiteroles. One patient died and a further two cases recovered after serious illness. Following this incident Health Protection NSW, worked closely with the Camperdown PHU, the NSW Food Authority, and NSW Health Service Support, (providers of food services to NSW public hospitals), to tighten requirements about Listeria control in foods served to patients and to improve communication protocols.

 

Respiratory Disease

In 2013 there were:

• 101 Legionnaires’ disease case notifications compared with 102 cases in 2012. A total of 54 cases were due to Legionella pneumophila infection, compared with 64 cases in 2012. Public health investigations did not identify any common sources for these L. pneumophila cases and they were evenly spread throughout the year. Notifications due to L. longbeacheae infection increased slightly (36 compared with 29 cases in 2012).

• 8,401 notifications of patients with laboratory confirmed influenza, a slight increase compared with 7,993 notifications in 2012. Both influenza A and B activity was highest in late August. Approximately 64% of laboratory-confirmed influenza was influenza A, with the influenza A(H1N1)pdm09 strain predominating. The number of influenza B notifications was higher than for any of the previous 5 years and accounted for 36% of laboratory confirmed influenza cases overall. Laboratory-confirmed influenza notifications represent only a small proportion of cases in the community. There was a large increase in the number of people presenting to emergency departments with influenza-like illness from June to September, with a peak in presentations in late August. There were fewer reported outbreaks of respiratory illness in aged-care and other residential care facilities in 2013 compared to previous years, and the rate of deaths attributed to influenza and pneumonia was low (a pattern seen previously influenza A(H1N1)pdm09 predominates.

• continued influenza prevention campaigns that focused on three key respiratory disease prevention messages: Cover your face when you cough or sneeze; Wash your hands; and Stay at home if you're sick so you don't infect others. The campaign also included distribution of The Spread of Flu is Up to You campaign posters, vaccination & pregnancy brochures, and infection control signage to health care facilities, aged care facilities and a range of other sectors.

• 430 notifications of tuberculosis, a steady decrease from the 451 and 511 cases reported in 2012 and 2011, respectively

• 8 cases of multi-drug resistant tuberculosis (MDR-TB). Eight cases were reported in 2010, 2011 and 2012 combined

• in collaboration with an expert sub-committee of the NSW Tuberculosis Advisory Committee, continued activities to strengthen tuberculosis prevention and control in Aboriginal communities in northern NSW, through a range of measures to increase screening, and increase early diagnosis.

 

Vector Borne Disease

In 2013 there were:

• 503 Ross River virus infection (RRV) notifications, a decrease from 604 in 2012. While the largest number of RRV cases was reported in the Hunter New England LHD (130 cases), Northern NSW LHD had the highest rate of notifications by population, followed by the Mid North Coast LHD.

• 431 Barmah Forest virus infection notifications, a 21% increase compared with the 357 notifications in 2012. This increase should be interpreted with caution as the use of a less specific serological test in 2013 is thought to have resulted in some false positive notifications. The geographical distribution of cases was similar to RRV, with the highest number of cases reported from residents of the Northern NSW, Mid North Coast and Hunter New England LHDs.

• 298 dengue fever case notifications, a small increase compared with the 289 notifications in 2012. The majority of the cases in 2013 were linked to international travel: Indonesia was the most commonly reported exposure site (40%), followed by Thailand (20%), India (6%) and the Philippines (6%). One case was acquired in NSW through exposure to the dengue virus in a research laboratory.

• no notifications of Kunjin virus, Murray Valley encephalitis virus, or other non-dengue flavivirus infections

• 24 Chikungunya virus infection notifications, a marked increase over the two cases reported in 2012. All were acquired overseas with thirteen cases acquired in Indonesia and five acquired in India.

• 87 malaria notifications, compared with 70 cases in 2012. All were acquired overseas. Travel to India was again the most commonly reported exposure site (26%), followed by Nigeria (11%).

 

Zoonotic Diseases

In 2013 there:

• was an increase in Q fever case notifications (168 compared with 123 in 2012). Q fever was the most commonly notified zoonotic disease in 2013.

• was a decrease in leptospirosis notifications (12 compared with 22 in 2012)

• was a slight decrease in brucellosis infections (3 compared with 6 in 2012). 2 cases were overseas-acquired and 2 infections were in feral pig hunters in Northern NSW.

• was an outbreak of Hendra virus (HeV) infection in horses on the north coast of NSW in June and July 2013. HPNSW worked closely with Lismore PHU and the NSW Department of Primary Industries (DPI) to respond to the outbreak, including conducting risk assessments of human contacts. None of the 16 identified contacts were assessed as “high risk” and none developed symptoms of HeV infection. Overall, 4 horses were confirmed with HeV infection and either died from the infection or were euthanised. A companion animal to one of the infected horses became the first documented natural clinical HeV infection of a dog and was also euthanised.

• were two outbreaks of highly pathogenic H7N2 avian influenza (AI) in animals on neighbouring poultry farms near Young in October 2013. HPNSW worked closely with Goulburn PHU and DPI to respond to the outbreak. There were 55 identified high-risk human contacts and public health staff employed a novel method of contact tracing via a web-based SMS transmission system. The purpose of the SMS was to remind identified contacts to self-monitor for influenza-like symptoms until the AI incubation period expired, plus prompt them to take daily prophylactic anti-influenza medication, where prescribed.

• was continued close work with the NSW Department of Primary Industries to manage zoonoses including developing and releasing joint factsheets on HeV and Australian Bat Lyssavirus and revising HeV quarantine procedures to include provision for companion animals.


Introduction: Communicable diseases

Definition and burden of disease in Australia

Bacteria, viruses or parasites infect humans as a result of contact with other infected humans, animals or the environment. Certain communicable diseases are of high priority for health departments around the world, because they are highly infectious, can result in serious illness or death, or can be prevented by immunisation or other actions.

Only in the last 200 years or so has the germ theory and the importance of some of the most important yet basic public health measures, such as availability of running water and hand-washing, been recognised. The development of immunisation, first against smallpox, and later for a growing number of other diseases including diphtheria, pertussis, tetanus, polio, and measles, led to massive declines in morbidity and mortality associated with these conditions.

The potential for serious outbreaks and emerging or re-emerging infectious diseases continue to present a challenge in public health and require planning and constant vigilance. Each year, over 200,000 individual notifications of communicable diseases are reported in Australia. These trigger a considerable amount of public health action so that cases are treated, the spread of disease is limited, the source of infection is removed or minimised and outbreaks are controlled or prevented.  

Public Health Act 2010

Under the Public Health Act 2010 (and previously under the Public Health Act 1991), laboratories, hospitals, medical practitioners, schools and child care centres must notify NSW Health of diagnoses of certain diseases. For some diseases a notification triggers a public health response by the public health unit, such as immunisation or prophylactic treatment of contacts. Notifications also provide valuable information that is used for planning and evaluation of prevention programs.

The number of notifications received for any particular condition is almost always an underestimate of the number of cases that actually occur. For a condition to be notified a patient must seek medical help, be diagnosed with the condition, in some cases must have the appropriate laboratory tests done and then the diagnosis must be reported to NSW Health. Nonetheless, communicable disease notifications provide valuable information on disease patterns in NSW.

References

Public Health Act 1991 and Public Health 2010. Available at  http://www.legislation.nsw.gov.au/maintop/view/inforce/act 127 2010 cd 0 N


Interventions: Communicable diseases

Immunisation

Immunisation remains the backbone of communicable disease control. Most preschool immunisations (>85%), are provided by general practitioners and a small proportion are provided by councils in NSW. Public health units provide high school based vaccination clinics. In 2013, NSW Health continued to facilitate high immunisation rates among children and adults through activities including:

• the Save the Date to Vaccinate awareness campaign (including television, radio, smartphone app and printed resources). The campaign evaluated well and there are plans to commence phase 2 of the campaign in 2014 http://www.immunisation.health.nsw.gov.au/.

new legislation to strengthen the immunisation requirements for enrolment into childcare in NSW. This included the development and distribution of an immunisation enrolment toolkit, parent brochure and advice on the NSW Heath website.

• an improvement in immunisation rates in Aboriginal children at 12 months of age from 85.9% in 2012 to 86.4% in 2013. The immunisation rate for Aboriginal children at 60 months (93.9%) was higher than for the general population (92.0%).

• the introduction of HPV vaccination for boys in Years 7 and 9. In the first year of this program, coverage for Year 7 males was only slightly below coverage in the established female vaccination program. 

• the development of a single consent form for Year 7 vaccinations to improve the parents’ experience, record management and data collection

• a new NSW Immunisation Schedule from 1 July 2013, including the introduction of two new vaccines (measles-mumps-rubella-varicella vaccine and Haemophilus influenza type b (Hib)-meningococcal C vaccine) into the schedule, and development and distribution of an Immunisation Provider Kit to explain the changes

• commencement of the Aboriginal Immunisation Health Worker Pilot with the employment of staff and completion of work plans aiming to identify and overcome barriers to immunisation in Aboriginal children 

• a new web-based vaccine ordering system, to provide greater efficiencies in the operations of the state vaccine centre, more reporting functionality for NSW Health and real-time feedback to immunisation providers when they place an order.

 

Blood Borne Virus

In 2013, NSW Health:

• developed the NSW HIV Support Program (HSP) to provide advice and support for doctors when they have newly diagnosed a patient with HIV infection.  By assisting doctors provide 5 Key Support Services to a newly diagnosed person, the person is supported to manage their infection and avoid transmitting HIV to another person. The 5 Key Support Services are: Appropriate clinical management; Psychosocial support; Counselling about HIV treatment and prevention of transmission of HIV to others; Contact tracing assistance; and Linkage to relevant specialist, community and peer support services. The HSP commenced on 9 May 2013 and by 31 December 2013 over 100 doctors inexperienced in HIV had been supported. The program was well received with most doctors indicating they found the support valuable. The HSP is continuing to evolve as Local Health Districts share experiences on models of implementation and resources and tools are developed.  A formal evaluation of the HSP will commence in 2014.

• commenced quarterly reporting on key HIV statistics, 6 weeks after the close of each quarter for monitoring the implementation of the HIV Strategy.

• strengthened surveillance of HIV infection by collecting information on viral load and HIV treatment uptake at the time of diagnosis. For the first time, information was available on HIV treatment coverage among people newly diagnosed with HIV in NSW. This is critical for tracking progress towards the goals set out in the NSW HIV Strategy 2012-2015. Of 355 NSW residents newly diagnosed with HIV in 2013, 140 (39%) had commenced HIV antiretroviral treatment around the time of diagnosis.

 

Enteric Diseases

NSW Health continues to work closely with the NSW Food Authority to investigate reports of potential food borne infection.

Salmonella Online Survey

In early 2013 a Salmonella Online Survey (SOS) was trialled to:

  • explore online surveys as a tool for rapid collection of salmonellosis risk factors
  • assess the suitability of using an online survey for disease follow up
  • reduce the time interval between onset of illness and public health follow-up.
  •  

    Over 300 people were invited to participate via a letter including a link to an online survey. A response rate of 22% was achieved. The survey responses frequently revealed foods or meals that were a likely source of the salmonellosis so advice could be given on safer alternatives, e.g. informing a case that smoothies containing raw egg are a particularly risky practice for salmonellosis.  An evaluation found the SOS to be both a useful and acceptable form of public health follow up for salmonellosis cases and HPNSW aims to refine the methodology of the SOS and trial it again in 2014.

     

    Enterovirus Outbreak Surveillance

    Although most enterovirus infections cause mild or no symptoms, they are also associated with a wide range of clinical diseases from hand-foot-and-mouth (HFM) disease to aseptic meningitis and acute flaccid paralysis. Transmission of enteroviruses, which includes the poliomyelitis virus, may occur directly via the faecal-oral route, contaminated environmental sources, or respiratory droplet transmission. Enterovirus infections (apart from poliomyelitis) are not notifiable in NSW.

    In early March 2013, paediatricians from the Northern Beaches area of Sydney alerted the Northern Sydney Local Health District Public Health Unit to an increase in the number of young children presenting with severe neurological manifestations of enterovirus infection. The Sydney Children’s Hospital Randwick confirmed human enterovirus 71 (EV71) in some of these cases and suspected infection in others.

    Human enterovirus 71 (or EV71) is a major cause of HFM disease worldwide, and in the last 15 years has caused large outbreaks in South East Asia associated with severe neurological disease and deaths. Large outbreaks have been rare in Australia but have been reported from Victoria, Western Australia, and in Sydney in 2000-01.

    NSW Health alerted clinicians and issued alerts to the community locally and statewide. The Sydney Children’s Hospital Network circulated advice to clinical staff on the diagnosis and management of patients with suspected neurological complications of enterovirus infection. Enhanced surveillance for current and recent cases of severe enterovirus infections in young children was implemented at both of Sydney’s Children’s Hospitals, and through the public hospital real-time emergency department surveillance system (PHREDSS) which demonstrated a gradual community spread of the infection to other parts of Sydney and outside Sydney. Over one hundred suspected cases were identified, which were found to be due to either EV71 or one of a number of other enteroviruses. The outbreak peaked in March and had declined by June 2013. While the enhanced hospital case surveillance was stopped in June, emergency department surveillance through PHREDSS continued.

    In November 2013 paediatricians at Children’s Hospital Westmead reported an increase in presentations of very young infants with fever, rash, and irritability. Testing showed that the infants were infected with parechovirus genotype 3, which has been recognised as causing similar outbreaks amongst infants in Europe, North America and Asia, but had not previously been recognised in Australia. In collaboration with public health units and clinical staff in the three tertiary paediatric hospitals active surveillance was established and alerts were disseminated to paediatricians and emergency departments. Overall, in the period from October 2013 to February 2014, 183 cases were confirmed in infants, from all parts of the state. PHREDSS surveillance was found to be a sensitive tool to track the outbreak, and the indicator (admission of infants presenting with fever/unspecified) continues to be monitored.


    For more information: Communicable diseases

    Useful websites include:

    NSW Communicable Diseases Reports web page at http://www.health.nsw.gov.au/Infectious/reports/Pages/default.aspx 

    NSW Infectious Diseases web page at http://www.health.nsw.gov.au/publichealth/infectious/index.asp

    Australian Government. Department of Health and Ageing. National Notifiable Diseases Surveillance System, available at http://www.health.gov.au/internet/main/publishing.nsf/content/cda-surveil-nndss-nndssintro.htm

    and  Communicable Diseases Intelligence at http://www.health.gov.au/internet/main/publishing.nsf/content/cda-pubs-cdi-cdiintro.htm

    Australian Bureau of Statistics at http://www.abs.gov.au

    Australian Institute of Health and Welfare at http://www.aihw.gov.au

    HealthInsite at http://www.healthinsite.gov.au

    Public Health Act 1991 and Public Health Act 2010. Available at  http://www.legislation.nsw.gov.au/maintop/view/inforce/act 127 2010 cd 0 N

     

    Immunisation

    National Immunisation Program Schedule at http://www.health.gov.au/internet/immunise/publishing.nsf/content/nips2

    NSW Ministry of Health Immunisation web page at http://www.health.nsw.gov.au/publichealth/immunisation/index.asp