Heat illness presentations to emergency departments in Western Sydney: surveillance for environmental, personal and behavioural risk factors.

OBJECTIVE: To pilot surveillance to describe environmental, personal and behavioural risk factors for people presenting to hospital emergency departments (EDs) with heat illness. METHODS: We conducted a retrospective case series and telephone interview study of people presenting to EDs across South Western Sydney, Western Sydney and Nepean Blue Mountains Local Health Districts with heat illness over the 2017/18 and 2018/19 summer periods (1 December to 28 February). We used the Public Health Rapid Emergency Disease Syndromic Surveillance (PHREDSS) 'heat problems' syndrome to identify people with heat illness and medical records to find contact details. We developed a detailed questionnaire instrument to guide the telephone interview. RESULTS: A total of 129 individuals presented with 'heat problems' (57 in 2017/18 and 72 in 2018/19). The median age was 44 years (range 1-89 years). Most attended hospitals via the NSW Ambulance Service (58%) or private car (40%). Of the total, 53% were classified as triage category 3 (potentially life-threatening), 27% as category 4 (potentially serious) and 16% as category 2 (imminently life-threatening). The main supplementary codes were heat exhaustion (35%), heat syncope (39%), and heat stroke (30%). The majority were discharged from the emergency department after completing treatment (73%), with 21% requiring admission. A total of 38 follow-up interviews were completed (29% response rate). Almost all individuals were exposed to heat outside their home environment: 11 (29%) were engaged in paid work, 5 (13%) in outdoor housework, and 10 (26%) in outdoor recreational activities. CONCLUSION: Our pilot surveillance study successfully collected home, local environment and behavioural risk factors on a small cohort presenting with 'heat problems' to EDs in Western Sydney during the summer months. Most were exposed to heat outdoors while engaged in work or recreation outside the home, and were preventable.

Developing a climate change inequality health impact assessment for health services.

OBJECTIVES: To develop a Climate Change Inequality Health Impact Assessment (CCIHIA) framework for health services; to provide a systematic process for assessing potential unequal health impacts of climate change on vulnerable and marginalised populations and places; to support effective planning to address these impacts; and to develop contextually appropriate local strategies. Type of program: A collaborative interdisciplinary scoping research project involving two universities and two local health districts (LHDs) in New South Wales (NSW) to develop a CCIHIA framework. This work builds upon the health impact assessment (HIA) approach, which systematically assesses proposals' potential health and equity impacts by involving stakeholders in developing responses. METHODS: The project involved four main activities: understanding stakeholder requirements; conceptualising climate change vulnerability; considering the role of health services; and integrating findings into a conceptual framework. RESULTS: Stakeholders identified key functions that should be addressed across the framing, process and utility of the CCIHIA framework. The resulting conceptual framework outlines contexts and social stratification, the differential impacts of climate change (including factors influencing unequal impacts) and the health system's position, and also identifies key potential points of intervention. LESSONS LEARNT: The challenge of addressing the complexity of factors and resulting health impacts is reflected within the CCIHIA framework. While there are many intervention points within this framework for health services to address, many factors influencing unequal impacts are created outside the health sector's direct control. The framework's development process reflected the focus on collaboration and the interdisciplinary nature of climate change response. Ultimately, the CCIHIA framework is an assessment tool and an approach for prioritising inclusive, cross-cutting, multisector working, and problem-solving.

Men who have sex with men, infectious syphilis and HIV coinfection in inner Sydney: results of enhanced surveillance.

UNLABELLED: Background The resurgence of infectious syphilis in men who have sex with men (MSM) has been documented worldwide; however, HIV coinfection and syphilis reinfections in MSM in inner Sydney have not been published. METHODS: For all laboratory syphilis notifications assessed as a newly notified case or reinfection, a questionnaire was sent to the requesting physician seeking demographic data and disease classification. Sex of partner and HIV status were collected for all infectious syphilis notifications in men received from 1 April 2006 to March 2011. RESULTS: From April 2001 to March 2011, 3664 new notifications were received, 2278 (62%) were classified as infectious syphilis. Infectious syphilis notifications increased 12-fold from 25 to 303 in the first and last year respectively, and almost all notifications were in men (2220, 97.5%). During April 2006 to March 2011, 1562 infectious syphilis notifications in males were received and 765 (49%) of these men were HIV-positive and 1351 (86%) reported a male sex partner. Reinfections increased over time from 17 (9%) to 56 (19%) in the last year of the study and were significantly more likely to be in HIV-positive individuals (χ(2)=140.92, degrees of freedom= 1, P=<0.001). CONCLUSION: Inner Sydney is experiencing an epidemic of infectious syphilis in MSM and about half of these cases are in HIV-positive patients. Reinfections are increasing and occur predominantly in HIV-positive men. Accurate surveillance information is needed to inform effective prevention programs, and community and clinician education needs to continue until a sustained reduction is achieved.

Prevalence of chronic hepatitis B in South Western Sydney: evaluation of the country of birth method using maternal seroprevalence data.

OBJECTIVE: To estimate the prevalence of hepatitis B infection and evaluate the country of birth (Census) method of describing hepatitis B distribution in an Australian health service with a large migrant population. METHODS: The prevalence of chronic hepatitis B in Sydney South West Area Health Service (SSWAHS, population 1.3 million) was estimated by applying the prevalence of hepatitis B surface antigen (HBsAg) in high or intermediate hepatitis B prevalence countries to SSWAHS residents from those countries, using 2006 Census data. The Australian hepatitis B prevalence (0.7%) was applied to the remainder. This method was validated using HBsAg seroprevalence in 42,274 women aged 15-44 years who delivered at SSWAHS public maternity hospitals during 2007 to 2009. RESULTS: The SSWAHS prevalence of HBsAg using the Census method was 2.0% for all ages and 2.3% for 15-44 year old women. The seroprevalence in 15-44 year old mothers was 1.8%. The adjusted population prevalence was 1.6%. The two methods produced broadly similar descriptions of relative hepatitis B burden by local government area and country of birth. CONCLUSION: The Census method overestimates the prevalence of hepatitis B infection by 30%, but produces similar patterns of hepatitis B burden across the area. Health services can estimate the prevalence and distribution of chronic hepatitis B using readily available data to focus delivery of prevention and treatment services.

Influenza A testing and detection in patients admitted through emergency departments in Sydney during winter 2009: implications for rational testing.

AIM: To examine factors associated with testing and detection of influenza A in patients admitted to hospital for acute care during the winter 2009 pandemic influenza outbreak. DESIGN, SETTING AND PARTICIPANTS: Retrospective observational study of patients who were tested for influenza A after being admitted to hospital through emergency departments of the Sydney South West Area Health Service from 15 June to 30 August 2009. MAIN OUTCOME MEASURES: The association of factors such as age, diagnosis at admission, hospital and week of admission with rates of testing and detection of influenza A. RESULTS: 17,681 patients were admitted through nine emergency departments; 1344 (7.6%) were tested for influenza A, of whom 356 (26.5%) tested positive for pandemic influenza. Testing rates were highest in 0-4-year-old children, in the peak period of the outbreak, and in patients presenting with a febrile or respiratory illness. Positive influenza test results were common across a range of diagnoses, but occurred most frequently in children aged 10-14 years (64.3%) and in patients with a diagnosis at admission of influenza-like illness (59.1%). Using multivariate logistic regression, patients with a diagnosis at admission of fever or a respiratory illness at admission were most likely to be tested (odds ratios [ORs], 15 [95% CI, 11-21] and 17 [95% CI, 15-19], respectively). These diagnoses were stronger predictors of influenza testing than the peak testing week (Week 4; OR, 7.0 [95% CI, 3.8-13]) or any age group. However, diagnosis at admission and age were significant but weak predictors of a positive test result, and the strongest predictor of a positive test result was the peak epidemic week (Week 3; OR, 120 [95% CI, 27-490]). CONCLUSION: The strongest predictor of a clinician's decision to test for influenza was the diagnosis at admission, but the strongest predictor of a positive test was the week of admission. A rational approach to influenza testing for patients who are admitted to hospital for acute care could include active tracking of influenza testing and detection rates, testing patients with a strong indication for antiviral treatment, and admitting only those who test negative to "clean" wards during the peak of an outbreak.

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.

Reflections on public health surveillance of pandemic (H1N1) 2009 influenza in NSW.

Surveillance has a fundamental role during public health emergencies to provide accurate and relevant information to guide decision making. For each phase of the NSW response to the pandemic H1N1 (2009) influenza there were significant differences in the public health surveillance objectives and response mechanisms. Consequently each phase placed a different emphasis on the various sources and types of surveillance information which were collected and reported upon. We examine whether the NSW public health surveillance systems were able to inform effective public health management throughout all phases of the pandemic (H1N1) 2009 influenza.