The increasing health burden of Legionella Pneumophila in NSW.

BACKGROUND: Legionella pneumophila can cause severe respiratory disease and is notifiable in NSW. An analysis of notifications linked to hospitalisation and death data over the period 2010-2022 was conducted to determine the burden of disease and any association with the introduction of NSW regulatory changes in 2018. METHODS: Cases were retrospectively identified from the Notifiable Conditions Records for Epidemiology and Surveillance (NCRES). Data on related morbidity and mortality were obtained from linked data within the NSW Communicable Disease Register (CDR). The impact of the regulatory change was evaluated by analysing monthly count data using an interrupted time series analysis. RESULTS: A total of 928 cases were notified with 84% admitted to hospital. Annual adjusted notification and admission rates increased over the period from 4.40 to 7.92 cases and 3.72 to 7.20 admissions, per 1,000,000 population, respectively. The mean length of hospital stay (LOS) was 14 days with a median of 8 days (range 1-262 days). Time series analysis identified an underlying increasing time trend in cases notified per month with an IRR of 1.069 (95% ci 0.751-1.523) post 2018 regulatory implementation. CONCLUSION: L. pneumophila is posing an increasing burden of disease with an underlying upward trend in notification incidence despite the introduction of regulatory changes in 2018. IMPLICATION FOR PUBLIC HEALTH PRACTICE: This study demonstrates how linking notification, hospitalisation and death data can measure the health burden of a notifiable condition. Furthermore, time-series analysis using these data is able to identify underlying temporal trends and evaluate policy changes.

Using the Australian Immunisation Register to support general practices to improve childhood vaccination rates.

BACKGROUND AND OBJECTIVES: Strategies to improve vaccination rates have been implemented with considerable benefits. The main objective of this study was to assess the impact of a supported general practice intervention to 'catch up' overdue children. METHOD: Between 2017 and 2018, a public health nurse visited 23 general practices with high numbers of overdue children to assist staff identify and follow up truly overdue children. A comparison group consisted of a random sample of overdue children from other practices. The intervention was assessed by reviewing Australian Immunisation Register (AIR) records in 2019. RESULTS: Although the intervention group had a significantly higher proportion of children who had their AIR records corrected for vaccines administered prior to the initial practice visit, the intervention did not result in higher vaccination rates. DISCUSSION: Support to general practices can improve vaccination data on the AIR; however, simple reminders alone are unlikely to increase vaccination rates for truly overdue children.

Identifying a more severe emergent COVID-19 variant using Emergency Departments' routinely collected clinical measures.

Objective: To determine whether a clinical scoring system (the mPRIEST score) could be used to identify an emerging coronavirus disease 2019 (COVID-19) variant with increased clinical severity. Design: Cross sectional study comparing two time periods (Delta and Omicron waves). Setting: Public Emergency Departments in Northern Sydney Local Health District. Participants: Patients presenting during August 2021 (Delta wave) and January 2022 (Omicron wave) with confirmed COVID-19. Data on age, gender, temperature, heart rate, systolic blood pressure, respiratory rate, oxygen saturation and mental status were extracted from patients' electronic medical records to assess clinical disease severity at presentation. Main outcome measures: Modified Pandemic Respiratory Infection Emergency System Triage (mPRIEST) score calculated using routinely collected data. Results: A sample of 262 records of COVID-19 positive patients presenting during the Delta and initial Omicron waves were reviewed with 205 having COVID-19 as their primary diagnosis. During the Delta wave 48.1% had scores above 4 compared to 35.1% for the Omicron wave (p = 0.03). The median score was also significantly higher for the Delta group (4 vs 3; p = 0.01). Hospitalisations, admissions to ICU and deaths during admission were higher among patients presenting during the Delta wave than among those presenting during the Omicron wave. Conclusion: The mPRIEST score was significantly higher for patients for whom the predominant circulating variant was Delta than those for whom the predominant circulating variant was Omicron. This finding is consistent with international reporting of severity measured by hospital admission data and demonstrates the score's possible ability to identify an emergent strain with higher morbidity and mortality.

Pertussis Morbidity in Children 12-59 Months of Age: A NSW Public Health Network Study.

BACKGROUND: Pertussis continues to be a significant public health problem despite high levels of vaccination. Although hospitalizations and deaths among children greater than 12 months of age are much less frequent than among infants less than 6 months of age, only limited information is available for this age group on other measures of morbidity. METHODS: A cross-sectional study with a 6-week follow-up component was conducted in New South Wales, Australia in 2017 to measure morbidity among children 12-59 months of age notified to health authorities. Measures used included cough duration, cough severity, constitutional symptoms and impacts on the family. Associations between these outcomes and age group, vaccination status, asthma, treatment and family structure were explored. RESULTS: Three hundred and five of 472 (65%) notified cases were interviewed at baseline with approximately 20% having a severe cough with no trend in prevalence across age groups. Forty-eight percent of cases had experienced 3 or more constitutional symptoms with rates significantly higher among younger children. Children who had received an 18-month booster vaccination were significantly less likely to experience 3 or more constitutional symptoms (odds ratio: 0.46, 95% confidence interval: 0.22-0.97). Fifty-one percent of cases were still coughing at 6 weeks. One-third of carers initially reported having disrupted sleep 4 or more nights per week with substantial disruption to carers' sleep still recorded at 6 weeks. CONCLUSIONS: Substantial morbidity was observed in this age group with some evidence that the reintroduction of an 18-month acellular pertussis booster lessened disease severity.

A Health-Based Metric for Evaluating the Effectiveness of Noise Barrier Mitigation Associated With Transport Infrastructure Noise.

INTRODUCTION: This study examines the use of the number of night-time sleep disturbances as a health-based metric to assess the cost effectiveness of rail noise mitigation strategies for situations, wherein high-intensity noises dominate such as freight train pass-bys and wheel squeal. MATERIALS AND METHODS: Twenty residential properties adjacent to the existing and proposed rail tracks in a noise catchment area of the Epping to Thornleigh Third Track project were used as a case study. Awakening probabilities were calculated for individual's awakening 1, 3 and 5 times a night when subjected to 10 independent freight train pass-by noise events using internal maximum sound pressure levels (LAFmax). RESULTS: Awakenings were predicted using a random intercept multivariate logistic regression model. With source mitigation in place, the majority of the residents were still predicted to be awoken at least once per night (median 88.0%), although substantial reductions in the median probabilities of awakening three and five times per night from 50.9 to 29.4% and 9.2 to 2.7%, respectively, were predicted. This resulted in a cost-effective estimate of 7.6-8.8 less people being awoken at least three times per night per A$1 million spent on noise barriers. CONCLUSION: The study demonstrates that an easily understood metric can be readily used to assist making decisions related to noise mitigation for large-scale transport projects.

The completeness of electronic medical record data for patients with Type 2 Diabetes in primary care and its implications for computer modelling of predicted clinical outcomes.

AIM: To describe the completeness of routinely collected primary care data that could be used by computer models to predict clinical outcomes among patients with Type 2 Diabetes (T2D). METHODS: Data on blood pressure, weight, total cholesterol, HDL-cholesterol and glycated haemoglobin levels for regular patients were electronically extracted from the medical record software of 12 primary care practices in Australia for the period 2000-2012. The data was analysed for temporal trends and for associations between patient characteristics and completeness. General practitioners were surveyed to identify barriers to recording data and strategies to improve its completeness. RESULTS: Over the study period data completeness improved up to around 80% complete although the recording of weight remained poorer at 55%. T2D patients with Ischaemic Heart Disease were more likely to have their blood pressure recorded (OR 1.6, p=0.02). Practitioners reported not experiencing any major barriers to using their computer medical record system but did agree with some suggested strategies to improve record completeness. CONCLUSION: The completeness of routinely collected data suitable for input into computerised predictive models is improving although other dimensions of data quality need to be addressed.

Using computer modelled life expectancy to evaluate the impact of Australian Primary Care Incentive programs for patients with type 2 diabetes.

AIMS: To evaluate the impact of enhanced primary care and practice incentive programs on the care of patients with type 2 diabetes in the Australian primary care setting using routinely collected data and computer modelling software. METHODS: Primary care patient data were electronically extracted from practices and inputted into the United Kingdom Prospective Diabetes Study (UKPDS) Outcomes model. A retrospective cohort study design was employed with predicted life expectancies compared between patients who had a recorded diabetes cycle of care (DCoC) and those who did not. Changes in glycated haemoglobin (HbA1c) were also analysed using a mixed-effects regression model. Potential life expectancy gains were estimated by inputting theoretical risk factors data consistent with current guidelines. RESULTS: Twelve primary care practices were recruited and suitable data were available for 559 people with type 2 diabetes. Two hundred and twenty five patients (40%) were identified as having completed at least one DCoC and as a group had a predicted additional life expectancy of 0.65 years (95% CI, -0.22 to 1.5). However, once this was adjusted for comorbidities the difference reduced to 0.03 years. There was no significant difference in HbA1c levels attributable to the intervention. An estimated 0.5 year of additional life expectancy was predicted should all patients have complied with current risk factor guideline recommendations. CONCLUSIONS: Computer modelling using routinely collected primary care data can be used to evaluate the effectiveness of primary care programs. However, there are some data availability and linkage limitations in the Australian setting.

Salmonellosis outbreak traced to playground sand, Australia, 2007-2009.

A community outbreak of gastroenteritis in Australia during 2007-2009 was caused by ingestion of playground sand contaminated with Salmonella enterica Paratyphi B, variant Java. The bacterium was also isolated from local wildlife. Findings support consideration of nonfood sources during salmonellosis outbreak investigations and indicate transmission through the animal-human interface.

Blood dioxin biomonitoring to assess local residents' exposure from a large urban remediation project.

BACKGROUND: A total of 265000 m(3) of dioxin contaminated soil and sediments from past industrial activity was treated on site in an urban setting in Sydney, Australia. To respond to local community concerns about potential dioxin exposure from fugitive emissions a human biomonitoring study was undertaken. OBJECTIVE: To determine whether local residents were exposed to significant amounts of dioxin from the remediation process. METHODS: Blood samples were collected from local residents around the site and a representative metropolitan control group. They were pooled within age and sex strata and the change in dioxin concentrations over the remediation period and a summary of the mid point and post remediation dioxin concentrations were compared between groups. Information on dietary intake was collected to look for possible confounding. RESULTS: The mean dioxin Toxic Equivalent concentrations (TeQ) decreased among both the local resident and control groups over the remediation period by 1.9 and 2.1 pg gm(-1) lipid respectively. Modelled blood concentrations adjusting for age and sex did not detect a significant difference between groups for changes in either TeQ or 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8 TCDD). The summary measure approach did however demonstrate that the 2,3,7,8 TCDD concentrations among the local resident group was approximately 0.7 pg g(-1) lipid higher compared to the control group post remediation. There were no significant changes in dietary intake sources of dioxin. CONCLUSION: Biomonitoring demonstrated that local residents were not exposed to significant quantities of dioxin. Large scale remediation of dioxin contaminated land can be safely undertaken in an urban setting.

Can data extraction from general practitioners' electronic records be used to predict clinical outcomes for patients with type 2 diabetes?

BACKGROUND: The review of clinical data extraction from electronic records is increasingly being used as a tool to assist general practitioners (GPs) manage their patients in Australia. Type 2 diabetes (T2DM) is a chronic condition cared for primarily in the general practice setting that lends itself to the application of tools in this area. OBJECTIVE: To assess the feasibility of extracting data from a general practice medical record software package to predict clinically significant outcomes for patients with T2DM. METHODS: A pilot study was conducted involving two large practices where routinely collected clinical data were extracted and inputted into the United Kingdom Prospective Diabetes Study Outcomes Model to predict life expectancy. An initial assessment of the completeness of data available was performed and then for those patients aged between 45 and 64 years with adequate data life expectancies estimated. RESULTS: A total of 1019 patients were identified as current patients with T2DM. There were sufficient data available on 40% of patients from one practice and 49% from the other to provide inputs into the UKPDS Outcomes Model. Predicted life expectancy was similar across the practices with women having longer life expectancies than men. Improved compliance with current management guidelines for glycaemic, lipid and blood pressure control was demonstrated to increase life expectancy between 1.0 and 2.4 years dependent on gender and age group. CONCLUSION: This pilot demonstrated that clinical data extraction from electronic records is feasible although there are several limitations chiefly caused by the incompleteness of data for patients with T2DM.

Automated data extraction from general practice records in an Australian setting: trends in influenza-like illness in sentinel general practices and emergency departments.

BACKGROUND: Influenza intelligence in New South Wales (NSW), Australia is derived mainly from emergency department (ED) presentations and hospital and intensive care admissions, which represent only a portion of influenza-like illness (ILI) in the population. A substantial amount of the remaining data lies hidden in general practice (GP) records. Previous attempts in Australia to gather ILI data from GPs have given them extra work. We explored the possibility of applying automated data extraction from GP records in sentinel surveillance in an Australian setting.The two research questions asked in designing the study were: Can syndromic ILI data be extracted automatically from routine GP data? How do ILI trends in sentinel general practice compare with ILI trends in EDs? METHODS: We adapted a software program already capable of automated data extraction to identify records of patients with ILI in routine electronic GP records in two of the most commonly used commercial programs. This tool was applied in sentinel sites to gather retrospective data for May-October 2007-2009 and in real-time for the same interval in 2010. The data were compared with that provided by the Public Health Real-time Emergency Department Surveillance System (PHREDSS) and with ED data for the same periods. RESULTS: The GP surveillance tool identified seasonal trends in ILI both retrospectively and in near real-time. The curve of seasonal ILI was more responsive and less volatile than that of PHREDSS on a local area level. The number of weekly ILI presentations ranged from 8 to 128 at GP sites and from 0 to 18 in EDs in non-pandemic years. CONCLUSION: Automated data extraction from routine GP records offers a means to gather data without introducing any additional work for the practitioner. Adding this method to current surveillance programs will enhance their ability to monitor ILI and to detect early warning signals of new ILI events.

An influenza outbreak among pilgrims sleeping at a school without purpose built overnight accommodation facilities.

This report describes a respiratory illness outbreak amongst a group of over 700 World Youth Day 2008 pilgrims staying at a basic accommodation venue for 1 week in July 2008. At this venue, 1 group of pilgrims was accommodated as a large group in a gymnasium and another group was sub-divided into smaller groups and accommodated in classrooms. Following confirmation of an influenza B outbreak by influenza point of care testing, control measures were promptly implemented. Isolation of cases, improved hand, respiratory and general hygiene, establishment of a mobile tent health facility at the accommodation venue, and the use of oseltamivir for the treatment of cases and prophylaxis of high risk contacts were implemented and the outbreak was brought under control within the week. Overall, 20% of pilgrims met the case definition for an influenza-like illness and 36% had an onset prior to arrival at the venue. The attack rate for those with onset while at the venue was significantly higher amongst pilgrims accommodated in the gymnasium than those staying in the classrooms. Findings from this study highlight the importance of early detection, the rapid implementation of control measures and appropriate prescribing of antivirals to manage influenza outbreaks. The findings also highlight the benefits of accommodating individuals in smaller groups within basic accommodation venues in the context of mass gatherings.

Who gives pertussis to infants? Source of infection for laboratory confirmed cases less than 12 months of age during an epidemic, Sydney, 2009.

An important approach to protecting infants against pertussis is to provide a booster vaccination to close contacts, however this strategy requires a good understanding of infection sources to be effective. The objective of this study was to identify the most important sources of transmission of pertussis infection to infants, regardless of hospitalisation status. Standardised interviews were conducted during routine follow-up calls with the parent or guardian of laboratory confirmed pertussis cases less than 12 months of age notified to 3 Sydney metropolitan public health units during a pertussis outbreak from January to May 2009. All contacts with a coughing illness or laboratory confirmed pertussis during the 3 weeks prior to onset of illness in the index case, were recorded. A source of infection could not be identified for 29 infants (31%) and a total of 86 known or suspected sources were identified for the other 66 infants. The most frequently identified sources were siblings (36%) and parents (24%), followed by other family members (21%), friends (13%), and settings outside the home such as medical centres (6%). Of 20 siblings aged 3 or 4 years, 16 (80%) were sources of infection, compared with 14 of the 44 (32%) other siblings less than 18 years of age. During this epidemic siblings were more important sources of infant infection than parents. Siblings aged 3 and 4 years of age were particularly important transmitters of pertussis infection to infants. Minimising pertussis infection in 3 and 4 year olds may be an important measure to prevent infant infection.

Isolation and quarantine during pandemic (H1N1) 2009 influenza in NSW: the operational experience of public health units.

During the DELAY and CONTAIN phases of pandemic (H1N1) 2009 influenza in NSW, public health units needed to rapidly surge operations to manage the 3070 potential cases and 1894 contacts notified to them. The Incident Control System, NetEpi (the web-based multi-user access database), training to up-skill surge staff, and electronic communication were all integral to the outbreak response. Ongoing identification and training of surge staff would assist a timely and effective response to future large scale outbreaks. Investing and incorporating information technology tools into routine public health unit business to assist with communication, outbreak management and reporting will improve familiarity and capability within the network to respond to public health emergencies.

Influenza outbreaks during World Youth Day 2008 mass gathering.

Influenza outbreaks during mass gatherings have been rarely described, and detailed virologic assessment is lacking. An influenza outbreak occurred during World Youth Day in Sydney, Australia, July 2008 (WYD2008). We assessed epidemiologic data and respiratory samples collected from attendees who sought treatment for influenza-like illness at emergency clinics in Sydney during this outbreak. Isolated influenza viruses were compared with seasonal influenza viruses from the 2008 influenza season. From 100 infected attendees, numerous strains were identified: oseltamivir-resistant influenza A (H1N1) viruses, oseltamivir-sensitive influenza A (H1N1) viruses, influenza A (H3N2) viruses, and strains from both influenza B lineages (B/Florida/4/2006-like and B/Malaysia/2506/2004-like). Novel viruses were introduced, and pre-WYD2008 seasonal viruses were amplified. Viruses isolated at mass gatherings can have substantial, complex, and unpredictable effects on community influenza activity. Greater flexibility by public health authorities and hospitals is required to appropriately manage and contain these outbreaks.

Investigating health effects in a community surrounding a road tunnel stack--a cross sectional study.

BACKGROUND: Extended tunnelled roadways requiring ventilation via exhaust stacks are an increasingly common solution to traffic congestion around the world. In response to community concerns about adverse health effects associated with emissions from a new road tunnel exhaust stack, despite no demonstrable change in local ambient air quality, we conducted a cross sectional study to test for an association between exposure to the exhaust stack emissions and the presence of eye, nose and throat symptoms. METHODS: Stack emissions were modelled and categorised into areas of high, medium and low levels of exposure to emissions. A telephone interview survey was conducted in these three zones. Multivariate analysis was undertaken using Cox Proportional Hazards modelling to estimate prevalence ratios between zones for eye, nose and throat symptoms. RESULTS: The prevalence of eye, nose and throat symptoms in the study area were 50 percent, 67 percent and 33 percent respectively and did not differ between the exposure zones. The presence of these symptoms was associated with a measure of reported "environmental worry". CONCLUSION: The study did not demonstrate a community wide health impact associated with modelled emissions but is unable to exclude the possibility of sensitive individuals being adversely affected.

Serum dioxin levels in Sydney Harbour commercial fishers and family members.

BACKGROUND: Commercial fishing in Sydney Harbour (SH) was banned in February 2006 as a result of high dioxin levels in some SH seafood. Because of concerns by some fishers about their own dioxin levels, testing of serum dioxin levels was offered to SH commercial fishers and their families. OBJECTIVES: Aims of this study were to describe blood dioxin levels of SH fishers and family members; compare these levels to background Australian levels and international data; analyze association between intake of SH seafood and dioxin levels; and assess whether blood dioxin levels were useful to inform ongoing care of SH fishers. METHODS: NSW Department of Health conducted clinics at which 112 fishers and family members gave blood for analysis of dioxin levels. Dioxin exposure was assessed through a questionnaire. Seafood dioxin levels were provided by the NSW Department of Environment and Climate Change. RESULTS: For the fishers (n=26), median TCDD and total TEQ levels were 27.3 and 62.4 pg g(-1) lipid, respectively. For the whole group (n=112), median TCDD and total TEQ levels were 9.3 and 26.1 pg g(-1) lipid, respectively. Age was the strongest predictor of increased dioxin levels (p<0.01), and consumption of SH seafood was also strongly associated (p=0.01). CONCLUSIONS: Serum dioxin levels in the SH fisher cohort were higher than Australian background levels, but comparable with other international high fish-eating communities, and lower than occupationally and accidentally exposed cohorts. High TCDD levels in commonly eaten seafood by the SH fishers confirms this as the likely exposure source.