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

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 (χ2 = 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.

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.

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.

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.

The interpretation of nucleic acid amplification tests for tuberculosis: do rapid tests change treatment decisions?

OBJECTIVES

To describe changes in treatment decisions after receipt of nucleic acid amplification (NAA) test for the diagnosis of M. tuberculosis.

METHODS

Retrospective notes review of treatment decisions in patients receiving a NAA test for suspected pulmonary or non-pulmonary tuberculosis at the Royal Free Hospital in London between March 2001 and February 2002. Notes were sought on a 50% random sample of patients with both smear and NAA negative specimens and all patients with other specimen results.

RESULTS

Two hundred and fifty patients were tested with NAA; clinical details were obtained on 138; 61 were ever treated. Seventeen (17/18) smear-negative patients were started on treatment after a positive NAA; none of six smear-negative patients treated prior to a negative NAA result had treatment stopped. Seventeen (17/21) smear-positive patients were treated prior to NAA result and all were NAA positive; treatment was delayed in four smear-positive patients until receipt of an NAA and one NAA-negative patient was not treated.

CONCLUSIONS

In routine practice a positive test in an untreated smear-negative patient leads to decision to treat in almost all, but the proportion testing positive is low (8% or 17/219). In patients already on treatment negative tests did not lead to decisions to stop.

Women who decline antenatal screening for HIV infection in the era of universal testing: results of an audit of uptake in three London hospitals

Universal screening for HIV in early pregnancy is strongly promoted policy in the United Kingdom with a target of 90 per cent uptake. We identified characteristics of women declining screening by conducting an audit at three hospitals in inner north London. In early 2002 midwives were asked to complete an audit form following first antenatal appointment. Of 2,710 women attending 401 (15 per cent) declined an HIV test. Of women who declined 38 per cent reported they had been tested for HIV in the past; 65 per cent accepted every other antenatal test. In multivariable analysis parity (OR: 1.19; 95 per cent CI 1.10-1.29 per additional child), declining other tests (OR: 3.10; 95 per cent CI 2.44-3.93 per test declined) and previous HIV testing (OR: 1.70; 95 per cent CI 1.30-2.23) were predictors of declining an HIV test. Women declining screening were not obviously from high-risk demographic groups: women from sub-Saharan Africa were not at greater risk of declining an HIV test than women from other regions.

Explaining risk factors for drug-resistant tuberculosis in England and Wales: contribution of primary and secondary drug resistance

Drug-resistant tuberculosis can be transmitted (primary) or develop during the course of treatment (secondary). We investigated risk factors for each type of resistance. We compared all patients in England and Wales with isoniazid- and multidrug-resistant tuberculosis in two time-periods (1993-1994 and 1998-2000) with patients with fully sensitive tuberculosis, examining separately patients without and with previous tuberculosis (a proxy for primary and secondary drug-resistant tuberculosis). Patients with previous tuberculosis smear positivity and arrival in the United Kingdom <5 years were strongly associated with multidrug resistance and isoniazid resistance. In patients with no previous tuberculosis HIV infection, residence in London and foreign birth were risk factors for multidrug resistance, and non-white ethnicity, residence in London and HIV infection for isoniazid resistance. Risk factors for each type of resistance differ. Elevated risks associated with London residence, HIV positivity, and ethnicity were mainly seen in those without previous tuberculosis (presumed transmission).

The community prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in older people living in their own homes: implications for treatment, screening and surveillance in the UK

Methicillin-resistant Staphylococcus aureus (MRSA) predominantly affects those over 65 years old. There may be a substantial pool of older people with MRSA in the community. We studied the prevalence in one London general practice, screening 258 older people living in their own home. MRSA (E-MRSA 15) was found in two participants (0.78%). Past history of MRSA was the only significant risk factor. The results of this and other studies suggest that national guidelines recommending early discharge for MRSA carriers have not resulted in widespread community acquisition amongst elderly people living in their own home. Community antibiotic policies for skin and soft-tissue infection do not require amendment. Patients with previous MRSA should be isolated and screened on admission especially to high-risk units.

Reasons for low reported treatment success in notified tuberculosis patients from a London hospital according to new outcome reporting

In January 2002 the Communicable Disease Surveillance Centre (CDSC) introduced outcome reporting for tuberculosis 12 months after start of treatment. To determine whether outcome could change with longer and more detailed follow up, we examined this at 12 months and two years for a cohort notified in 2000 at a central London hospital. At 12 months 61/94 (65%) notified patients had completed treatment, 10 (16%) had died, 11 (12%) were lost to follow up, six (6%) were transferred to another service in the UK, four (4%) were still on treatment, and treatment for one (1%) patient had been stopped. After a mean follow up of two years, 65 (69%) had completed treatment. In this London service with a high prevalence of HIV infection (at least 23%), low treatment success was due to deaths, transfers and losses to follow up. The last of these was often due to patients returning to their country of origin (7 of 11). Tuberculosis was the primary or contributing cause of death in at least 4/94 (4%) cases. Completion rates need to be interpreted with caution particularly in specialist units with highly mobile populations. This has implications for national targets as well as for models of care.

The Australian Childhood Immunisation Register: validation of the immunisation status of children who are very overdue

OBJECTIVES

To determine the true immunisation status of children identified by the Australian Childhood Immunisation Register (ACIR) as 90 days overdue, and determine why appropriately immunised children were flagged as overdue.

METHODS

A telephone survey of immunisation providers and/or parents of a stratified random sample of 850 NSW children born on or after 1 January 1996 and identified by the ACIR as 90 days overdue for at least one scheduled immunisation at 17 June 1997. The survey was conducted in June to September 1997.

RESULTS

Children in the sample ranged in age from 5 to 17 months. Only 526 (61.9%) could be traced. Of these, 452 (86.6%) were fully immunised, and 75% of immunisations were given on time (within 30 days of falling due). The overall proportion of NSW children identified by ACIR as 90 days overdue who were fully immunised was an estimated 85% (95% CI 82.6%-87.4%). For the 452 fully immunised children, a reason for the child's immunisation not appearing on the register could be attributed for only 248/452 (54.8%). There was evidence that the provider had failed to submit an encounter form for 141 of these children.

CONCLUSIONS

In mid-1997, more than half the children identified by ACIR as 'overdue' were fully immunised. A significant reason for fully immunised continuing to be flagged as overdue was failure to return encounter forms.

IMPLICATIONS

At the time of survey the ACIR could not accurately identify unimmunised children and was of limited use as a tool for public health services to follow up very overdue children.