Is the evidence-based medicine movement counter-productive: are randomised controlled trials the best approach to establish evidence in complex healthcare situations?

In the modern era, evidence-based medicine (EBM) has been embraced as the best approach to practising medicine, providing clinicians with 'objective' evidence from clinical research. However, for presentations with complex pathophysiology or from complex social environments, sometimes there remains no evidence, and no amount of research will obtain it. Yet, health researchers continue to undertake randomised controlled trials (RCT) in complex environments, ignoring the risk that participants' health may be compromised throughout the trial process. This paper examines the role of research that seeks to obtain evidence to support EBM. We provide examples of RCTs on ear disease in Aboriginal populations as a case-in-point. Decades of ear research have failed to yield statistically significant findings, demonstrating that when multiple factors are at play, study designs struggle to balance the known disease process drivers, let alone unknown drivers. This paper asks the reader to consider if the pursuit of research is likely to produce evidence in complex situations; or if perhaps RCTs should not be undertaken in these situations. Instead, clinicians could apply empirical evidence, tailoring treatments to individuals while taking into account the complexities of their life circumstances.

How accurate is presumptive Chlamydia trachomatis treatment? A 6-month clinical audit of a walk-in sexual health service.

Background Chlamydia trachomatis (chlamydia) is highly prevalent and is an important sexually transmitted infection as it can lead to increased risk of HIV seroconversion; and if left untreated, can cause infertility in women. Clinical guidelines recommend treating chlamydia presumptively when presenting symptomatically; however, clinicians are now questioning this due to increasing prevalence of antimicrobial resistance. Methods To determine the accuracy of presumptive chlamydia treatment practices at a walk-in sexual health service in regional Australia, we audited all same-day screen and treat presentations prescribed azithromycin over a 6-month period in 2018. Results A total of 325 cases were included in the analysis. Over half (54%) the presentations returned negative pathology for all pathogens investigated. One quarter (25%) of presentations were positive for chlamydia, and (4%) reported a dual infection. A further one fifth (20%) were negative for chlamydia but positive for another pathogen. More symptomatic males than females returned positive pathology for chlamydia (8% vs 4%). Conclusions While presumptive treatment is recommended in the current guidelines, our findings indicate this resulted in over-treatment. Considering the increasing resistance patterns for Mycoplasma genitalium, which include azithromycin, presumptive treatments need to balance immediate client care needs against long-term community antimicrobial resistance outcomes. This internal audit provided a feedback mechanism to the walk-in sexual service, enabling modification of practices to provide more precise, individual clinical care within the bounds of current STI guidelines, while balancing wider the objectives of antimicrobial stewardship.

A rapid review of evidence to inform an ear, nose and throat service delivery model in remote Australia.

INTRODUCTION: This rapid literature review aimed to inform the development of a new sustainable, evidence-based service delivery model for ear, nose and throat (ENT) services across Cape York, Australia. This work seeks to investigate the research question: 'What are the characteristics of successful outreach services which can be applied to remote living Indigenous children?' METHODS: A comprehensive search of three major electronic databases (PubMed, CINAHL and MEDLINE) and two websites (HealthInfo Net and Google Scholar) was conducted for peer-reviewed and grey literature, to elicit characteristics of ENT and hearing services in rural and remote Australia, Canada, New Zealand and the USA. The search strategy was divided into four sections: outreach services for rural and remote communities; services for Indigenous children and families; telehealth service provision; and remote ear and hearing health service models. A narrative synthesis was used to summarise the key features of the identified service characteristics. RESULTS: In total, 71 studies met the inclusion criteria and were included in the review, which identified a number of success and sustainability traits, including employment of a dedicated ear and hearing educator; outreach nursing and audiology services; and telehealth access to ENT services. Ideally, outreach organisations should partner with local services that employ local Indigenous health workers to provide ongoing ear health services in community between outreach visits. CONCLUSION: The evidence suggests that sound and sustainable ENT outreach models build on existing services; are tailored to local needs; promote cross-agency collaboration; use telehealth; and promote ongoing education of the local workforce.

Acute kidney injury in Indigenous intensive care patients.

BACKGROUND: Patients presenting to intensive care units (ICUs) report high rates of acute kidney injury (AKI) requiring renal replacement therapy (RRT). Globally, Indigenous populations report higher rates of renal disease than their non-Indigenous counterparts. OBJECTIVES: This study reports the prevalence, presenting features, and outcomes of Indigenous ICU admissions with AKI (who require RRT) within an Australian ICU setting and compares these with those of Indigenous patients without AKI. METHOD: A retrospective database review examined all Indigenous patients older than 18 years admitted to a regional Australian ICU between June 2013 and June 2016, excluding patients with chronic kidney disease requiring dialysis. We report patient demography, presenting clinical and physiological characteristics, ICU length of stay, hospital outcome, and renal requirements at three months after discharge, on Indigenous patients with AKI requiring RRT. RESULTS: AKI requiring RRT was identified in 15.9% of ICU Indigenous patients. On univariate analysis, it was found that these patients were older and had a higher body mass index, lower urine output, and higher levels of creatinine and urea upon presentation than patients who did not have AKI. Patients with AKI reported longer ICU stays and a higher mortality rate (30%, p < 0.05), and 10% of these required ongoing RRT at 3 months. Multivariate analysis found significant associations with AKI were only found for presenting urine outputs, urea and creatinine levels. CONCLUSIONS: This study reports higher rates of AKI requiring RRT for Indigenous adults than non-Indigenous adults, as has been previously published. Benefits arising from this study are as follows: these reported findings may initiate early targeted clinical management and can assist managing expectations, as some patients may require ongoing RRT after discharge.

Participatory Action Research Applied to an Ear, Nose, and Throat Specialty Service Redesign in Remote Australia: A Mixed-Methods Study of Key Stakeholder Perspectives.

This mixed-methods study reports on the key stakeholders' perspectives on the ear, nose, and throat (ENT) service redesign in remote Australia, using a participatory action research (PAR) approach. A primary health care (PHC) clinician survey was conducted to assess local needs and possible educational gaps in clinical knowledge. This was followed by an internal stakeholder forum and a follow-up survey with Torres and Cape Hospital and Health Service staff to gain their perspectives on current service delivery and table ideas for a new ENT health service model. Qualitative data were analyzed inductively and grouped in emerging themes. Quantitative data were imported into tables and analyzed descriptively. PAR allowed for input from 19 PHC clinicians, 10 face-to-face stakeholders perspectives, and 18 stakeholder follow-up survey respondents. Four themes emerged: 1. Training for health workers in ENT management; 2. Improved local service access; 3. New referral pathways to improve continuity of care; and 4. Introduction of telehealth. PAR engaged key stakeholders, identifying gaps in ENT service delivery, and guided the development of the new service model. The inclusion of stakeholders throughout the service redesign process is likely to create a more sustainable model of care which already has local "buy-in".

Reducing ear, nose and throat (ENT) waitlists: Implications of a referral audit.

INTRODUCTION: Many specialist waitlists in Australian hospitals are long. One reason anecdotally reported for this is poor alignment of referrals with current recommended guidelines. This paper reports the findings of an audit undertaken in 2017 for ear, nose and throat (ENT) surgeon referrals submitted by primary health centres within Cape York, Australia. MATERIALS AND METHODS: 54 long-wait ENT referrals were reviewed against referral criteria for ENT presentations using the Clinical Prioritization Criteria (CPC) and two routinely applied clinical primary health care guidelines; with findings reported alongside patient demography. RESULTS: All of the long wait ENT referrals in the sample were for remote living Indigenous Australians, most were children (93%). One fifth of referrals fulfilled all referral criteria and were appropriate (22%); one third required further informaiton to support the referral, either audiology or clinical history (30%); and half were inappropriate referrals (48%). CONCLUSION: Although many referral submissions did not adhere to CPC or routine guidelines, this audit enabled the identification of improvements to the referral system including the development of a checklist and flow-chart, plus patient information resources aimed at improving patient adherence. A case can be made for a new service delivery model that provides ongoing primary health education and facilitates improved ENT access. These strategies may improve ENT referral quality and decongest current ENT specialist waitlists, while offering improved primary health care management of ear presentations.

Ear, nose, and throat surgical access for remote living Indigenous children: What is the least costly model?

RATIONALE, AIMS, AND OBJECTIVES: This costing evaluation compares three service delivery models for ear, nose, and throat (ENT) surgery for remote living Indigenous children to improve their hearing outcomes, with the aim to identify the least costly model. METHODS: The main outcome measure presented was the incremental cost difference between the base case (Model 1) and two alternative models (Model 2, 3). The costs in 2017 Australian dollars are assessed from two viewpoints: (1) health system perspective, and (2) patients and their families including travel out-of-pocket expenses, presented separately according to the funding source. RESULTS: Findings indicate that the least costly model offered low-risk ENT surgery from a state funded hospital in a remote setting, with high use of videoconference technology: TeleHealth (Model 3) could save $3626 to $5067 per patient, compared with patients travelling to a regional centre public hospital (Model 1). A federally funded scheme which allowed groups of patients to access a direct flight charter transfer to the private hospital in regional centre (Model 2) reduced the cost by $2178 to $2711 per patient when compared with standard care (Model 1). From a societal perspective, Model 1 required out-of-pocket patient expenses, with greater time away from home, and hence appears the least preferred option. CONCLUSIONS: The sensitivity analyses also demonstrate that Model 3 would be the more economical model for providing ENT surgery for remote living children. By proving an accurate assessment of the true costs of delivering these important ear and hearing health services, strategic health service planners may be better informed and sufficient budgets can be allocated to provide improved service delivery. The benefits of Model 3, over Models 1 or 2, would also incorporate improvements to patient safety as a result of reducing patient travel, which should in-turn, reduce failure-to-attend rates.

An innovative approach to improve ear, nose and throat surgical access for remote living Cape York Indigenous children.

INTRODUCTION: On a background of high rates of severe otitis media (OM) with associated hearing loss, children from the Torres Strait and Cape York region requiring ear, nose and throat (ENT) surgery, faced waiting times exceeding three years. After numerous clinical safety incidents were raised, indicating a failure of the current system to deliver appropriate care, the governing Hospital and Health service opted to deliver surgical care through an alternate process. ENT surgeries were performed on 16 consented children from two remote locations via the private health care system, funded by a health provider partnership. METHODS: We examined the collaboration processes alongside clinical findings from this ENT surgery. Collated patient data, included patient demographics, clinical and audiometry presentation features were reviewed and compared pre and post-operatively. Cost savings associated with the use of TeleHealth post-operatively were briefly examined. RESULTS: Surgeries were successfully completed in all 16 children. The reported mean waitlist time for ENT surgery was 1.2 years. Pre-surgery pure-tone average hearing thresholds were reported at left: 30.9 dB, right: 38.2 dB. The majority of presentations were for bilateral OM with Effusion (69%). Post-surgical follow up indicated successful clinical outcomes in 80% of patients and successful hearing outcomes in 88% of patients. Mean difference pure-tone average hearing thresholds, left: 8.4 dB and right: 11.2 dB. Furthermore, the majority of patients reported improved hearing and breathing. The use of TeleHealth for post-operative review enabled a minimum cost saving of AUD$21,664 for these 16 children. Overall, a high level of staffing resources was required to successfully coordinate this intense surgical activity. CONCLUSION: This innovative approach to a health system crisis enabled successful ENT surgical and hearing outcomes in 16 children, whose waitlisted time grossly exceeded state health recommendations. Using private health facilities funded by a health partnership, while unlikely to be a suitable model of care for routine service delivery; may be applied as an adjunct service model when blockages and delays lead to sub-standard service provision. This approach may be applicable to other health care facilities when facing extended elective surgery wait times in ENT or other specialty areas.

Determining meteorological drivers of salt marsh mosquito peaks in tropical northern Australia.

In northern Australia the northern salt marsh mosquito Aedes vigilax is a vector of Ross River virus and is an appreciable pest. A coastal wetland adjacent to Darwin's residential suburbs offers a favorable habitat for Ae. vigilax, and despite vigilant mosquito control efforts, peaks of Ae. vigilax occur in excess of 500/trap/night some months. To improve mosquito control for disease and nuisance biting to nearby residential areas, we sought to investigate meteorological drivers associated with these Ae. vigilax peaks. We fitted a cross-sectional logistic regression model to weekly counts of female Ae. vigilax mosquitoes collected between July, 1998 and June, 2009 against variables, tide, rainfall, month, year, and larval control. Aedes vigilax peaks were associated with rainfall during the months September to November compared with January, when adjusted for larval control and tide. To maximize mosquito control efficiency, larval control should continue to be implemented after high tides and with increased emphasis on extensive larval hatches triggered by rainfall between September and November each year. This study reiterates the importance of monitoring and evaluating service delivery programs. Using statistical modelling, service providers can obtain solutions to operational problems using routinely collected data. These methods may be applicable in mosquito surveillance or control programs in other areas.

Lethal ovitrap deployment for Aedes aegypti control: potential implications for non-target organisms.

In Australia, dengue control combines source reduction with lethal ovitraps to reduce Aedes aegypti populations during outbreaks. Lethal ovitraps are considered a sustainable and environmentally friendly method of controlling container-inhabiting mosquitoes, however, to-date, this claim has not been quantified. This study assesses the potential impact of lethal ovitraps on non-target organisms when used to control Ae. aegypti in tropical Australia. For retention of specimens, we substituted standard sticky ovitraps for lethal ovitraps. We collected 988 Ae. aegypti and 44,132 non-target specimens over 13 months from 16 sites. Although Ae. aegypti comprised only 2.2% of the total collection, they were were the eighth most dominant taxa collected, on the 93(rd) percentile. Of the non-target organisms, Collembola were the dominant taxa, 44.2%, with 36.8% and 10.5% Diptera and Hymenoptera, respectively. Of the Dipterans, 61% were family Phoridae. Lethal ovitraps were visited by 90 insect or invertebrate families in total. Ovitraps are attractive to Collembola, Phoridae, Sciaridae, Formicidae, and Culicidae, with minimal attraction by Apidae and other commonly monitored non-target organisms. For container-inhabiting mosquitoes, LOs are cost effective operationally, requiring minimal staff resources for placement and retrieval.

Residual and pre-treatment application of starycide insect growth regulator (triflumuron) to control Aedes aegypti in containers.

BACKGROUND: Dengue is not endemic in Australia, although the vector mosquito Aedes aegypti is. In order to prevent dengue establishment, Australia maintains tight control of vector mosquitoes. Tight control programs often necessitate regular repeat application of treatments, and this is resource intensive. We sought to investigate the efficacy and longevity of triflurumon Starycide® Insect Growth Regulator under field conditions in tropical Australia against Aedes. We compared two doses (0.48 and 0.96 ppm), applied to water receptacles with delayed flooding by zero, two, and four weeks. RESULTS: We found greater than 90% inhibition of pupae development was achieved for up to 12 weeks. A dose of 0.96 ppm, when delayed for two or four weeks before flooding, provided 50 times inhibition relative to controls, for up to 22 weeks, suggesting triflumuron bound to the plastic substrate and offered a greater residual effect than applications without delayed flooding. CONCLUSION: We conclude that triflurumon offers excellent efficacy and longevity against Aedes in artificial containers. If deployed under standard conditions, re-application may not be required for up to 22 weeks, furthermore, initial applications could be performed under dry conditions, and this application method may improve the residual effects.

Operational use of household bleach to "crash and release" Aedes aegypti prior to Wolbachia-infected mosquito release.

Dengue (family Flaviviridae, genus Flavivirus, DENV) remains the leading arboviral cause of mortality in the tropics. Wolbachia pipientis has been shown to interrupt DENV transmission and is presently being trialled as a biological control. However, deployment issues have arisen on methods to temporarily suppress wild mosquito populations before Wolbachia-infected mosquito releases. By suppressing wild populations, fewer Ae. aegypti releases are required to achieve a sustainable Wolbachia density threshold. Furthermore, public distress is reduced. This study tests the application of domestic bleach (4% NaCIO) to temporarily "crash" immature Aedes populations in water-filled containers. Spray application NaClO (215 ppm) resulted in a mean 48-h mortality of 100, 100, 97, and 88% of eggs, second-instar larvae, fourth-instar larvae, and pupae, respectively. In the field, NaClO delayed ovipositing by 9 d in cooler months, and 11 d in hotter months, after which oviposition resumed in treated receptacles. We found bleach treatment of pot-plant bases did not cause wilting, yellowing, or dropping of leaves in two ornamental plants species. Domestically available NaClO could be adopted for a "crash and release" strategy to temporarily suppress wild populations of Ae. aegypti in containers before release of Wolbachia-infected mosquitoes. The "crash and release" strategy is also applicable to other mosquito species, e.g., Aedes albopictus (Skuse), in strategies using released mosquitoes.

Bacillus thuringiensis var. israelensis misting for control of Aedes in cryptic ground containers in north Queensland, Australia.

In Australia, dengue is not endemic, although the vector mosquito Aedes aegypti is established in far north Queensland (FNQ). Aedes albopictus has recently invaded the Torres Strait region, but is not established on mainland Australia. To maintain dengue-free, public health departments in FNQ closely monitor introduced dengue infections and confine outbreaks through rigorous vector control responses. To safeguard mainland Australia from Ae. albopictus establishment, pre-emptive strategies are required to reduce its breeding in difficult to access habitats. We compare the residual efficacy of VectoBac WDG, Bacillus thuringiensis var. israelensis (Bti) formulation, as a residual treatment when misted across a typical FNQ bushland using a backpack mister (Stihl SR 420 Mist Blower) at two dose rates up to 16 m. Semi-field condition results, over 16 weeks, indicate that Bti provided high mortality rates (> 80%) sustained for 11 weeks. Mist application penetrated 16 m of dense bushland without efficacy decline over distance.

A comparison of adult mosquito trapping regimes across seasons and ecosystems in Darwin, Australia.

Mosquitoes are problematic as vectors and pests in many tropical cities, including Darwin, the principal city in the Northern Territory of Australia. To monitor peaks in mosquito populations, the Medical Entomology unit of the Health Department sets overnight CO(2) -baited traps weekly. Trap setting and retrieving, followed by mosquito counting and identification, are labor intensive. Aiming to reduce this workload, we tested the hypothesis that fortnightly trapping is as effective as weekly trapping across seasons and ecologically distinct systems in Darwin. We applied cross-sectional negative binomial mixed effects models, which adjusted for rain and calendar month, to existing historical data. Culex annulirostris peaks were effectively identified using fortnightly trapping across all three ecological systems, during wet/dry and build-up seasonal patterns. For Aedes vigilax, fortnightly trapping was adequate in identifying peaks during wet and dry season months, but inadequate during build-up months across all three ecological systems. Therefore, weekly trapping should continue during build-up months, but trapping could be reduced to fortnightly for wet and dry season months for all ecological systems. Trapping for Cx. annulirostris monitoring could be reduced to fortnightly in all areas and seasons. Evaluation of programs can maximize staff efficiency and improve service delivery by reducing the need for unnecessary tasks.

The continuing role of Haemophilus influenzae type b carriage surveillance as a mechanism for early detection of invasive disease activity.

Prior to the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines, Hib was the leading cause of bacterial meningitis in children under five years of age worldwide. In countries that have adopted Hib vaccination schedules, invasive disease has reduced markedly. Oro-naso pharyngeal carriage is recognized as the most significant source of infection. Hib carriage is significantly associated with poverty, such as overcrowding, poor ventilation in houses, lack of running water, and high smoking rates. Additionally, many Indigenous minority groups report high rates of Hib carriage. A resurgence of Hib disease among Alaskan children in the 1990s, lead to a change in approach to eliminate Hib disease and carriage in high-risk populations. This new approach identifies strategies for eliminating Hib disease focusing on the reservoirs of colonization within families and communities. Monitoring Hib carriage continues to offer an early warning system, whereby intervention could prevent invasive disease resurgence.

The epidemiology of community acquired bacteremic pneumonia, due to Streptococcus pneumoniae, in the Top End of the Northern Territory, Australia--over 22 years.

BACKGROUND: Diseases caused by Streptococcus pneumoniae continue to cause substantial morbidity and mortality throughout the world. Furthermore, detrimental outcomes are more pronounced in some populations--such as those living in third world poverty, and Indigenous people who live in developed nations. METHODS: This study describes the epidemiology of blood culture positive S. pneumoniae community-acquired pneumonia (CAP) in the Top End of the Northern Territory of Australia. Demographics, indigenous status, medical risk factors, serotype and outcomes were collected from adults presenting to hospital with blood culture positive S. pneumoniae CAP, from 1987 to 2008. RESULTS: We report 205 cases, with a median age of 40 years. The average overall incidence rate ratio was 10.3 for indigenous adults compared with non-indigenous adults. There was no statistical difference between incidence rates pre and post-23-valent pneumococcal polysaccharide vaccine (23vPPV) introduction. Serotypes in presenting cases were predominantly (84.7%) 23vPPV types. The whole-population logistic regression model identified significant adjusted relative risks: 95% CI, for age 45 and older 1.6: 1.1, 2.2, indigenous 5.9: 3.7, 9.5, diabetes 2.3: 1.6, 3.3, excess alcohol 4.8: 2.8, 8.3, smoking 2.7: 1.9, 3.7 with indigenous+excess alcohol 18.5: 17.3, 19.7 as predictive for bacteremic S. pneumoniae CAP presentation. CONCLUSIONS: Our results suggest that, the national 23vPPV program appears to be under-utilized. An integrated Public Health approach vigorously targeting indigenous adolescents, before substances such as alcohol and smoking are habitual, together with increased vaccine coverage, will reduce the burden of pneumococcal disease in this population.

Arbovirus models to provide practical management tools for mosquito control and disease prevention in the Northern Territory, Australia.

Ross River virus (RRV) causes the most common human arbovirus disease in Australia. Although the disease is nonfatal, the associated arthritis and postinfection fatigue can be debilitating for many months, impacting on workforce participation. We sought to create an early-warning system to notify of approaching RRV disease outbreak conditions for major townships in the Northern Territory. By applying a logistic regression model to meteorologic factors, including rainfall, a postestimation analysis of sensitivity and specificity can create rainfall cut-points. These rainfall cut-points indicate the rainfall level above which previous epidemic conditions have occurred. Furthermore, rainfall cut-points indirectly adjust for vertebrate host data from the agile wallaby (Macropus agilis) as the life cycle of the agile wallaby is intricately meshed with the wet season. Once generated, cut-points can thus be used prospectively to allow timely implementation of larval survey and control measures and public health warnings to preemptively reduce RRV disease incidence. Cut-points are location specific and have the capacity to replace previously used models, which require data management and input, and rarely provide timely notification for vector control requirements and public health warnings. These methods can be adapted for use elsewhere.

Haemophilus influenzae type b carriage in Indigenous children and children attending childcare centers in the Northern Territory, Australia, spanning pre- and post-vaccine eras.

UNLABELLED: This paper investigates Haemophilus influenzae type b (Hib) carriage in Indigenous children and children attending childcare centres in the Northern Territory of Australia, 1992-2005. More than 10 years after the introduction of the Hib conjugate vaccine, Hib carriage persists in Indigenous children (3.4%, 2003-2005) and children attending childcare centres (0.2%, 2004). This is the first Australian study to examine Hib carriage spanning the pre- and post-vaccination eras. Increasing carriage rates contribute to Hib disease resurgence especially in those with higher disease burdens, such as remote Indigenous Australians, ongoing carriage surveillance provides a sentinel warning system for invasive disease. BACKGROUND: Following the introduction of H. influenzae type b (Hib) conjugate vaccine to Australia in 1993 as a three dose (2, 4, 12 month) schedule, the incidence of Hib disease decreased dramatically in children, especially in those aged under 5 years. We investigate Hib carriage in Indigenous children and children attending childcare centres from the Northern Territory (NT) of Australia between 1992 and 2005. We report Hib carriage rates in this well vaccinated population, with previously documented high rates of invasive disease. METHODS: Hib carriage was reviewed in nasopharyngeal or nasal swabs collected between 1992 and 2005; from over 2000 children (61% Indigenous) aged 0-6 years enrolled in 7 otitis media or carriage surveillance studies in the NT. RESULTS: More than 10 years after the introduction of the Hib conjugate vaccine, Hib carriage persists at low levels, but at a higher rate in Indigenous children (3.4%, 2003-2005) than children attending childcare centres (0.2%, 2004), in the NT of Australia. CONCLUSIONS: This is the first Australian study to examine Hib carriage spanning the pre- and post-vaccination eras. Ongoing carriage surveillance provides a sentinel warning system for invasive disease. This notifies public health professionals of potential invasive disease, creating early warning systems for intervention if Australian Indigenous children or children attending childcare centres are to follow current international trends associated with high rates of carriage preceding invasive disease-despite high vaccination rates. Internationally there is growing concern that increasing carriage rates are the driving force behind Hib disease resurgence especially in those with higher disease burdens, such as remote Indigenous Australians. Changes to the vaccination schedule from PRP-OMPC (PedvaxHIB(®)), to PRP-T (2, 4, 6, 12 months) from January 2010-may affect carriage and in time, invasive disease rates. This work is important for national and International comparisons as well as feeding back information to vaccine policy makers of the Hib carriage environment throughout this period.

Warmer waters in the Northern Territory--herald an earlier onset to the annual Chironex fleckeri Stinger season.

The discovery that Chironex fleckeri occurs annually in northern Australia occurred long ago, possibly before written records were available by local indigenous people, however, to date the precision of this yearly phenomenon is still not fully understood. Sea surface temperature (SST) appears to be a determining factor signaling the "arrival" of C. fleckeri each year. Anthropogenic climate change modeling predicts global rises in SST. Rises in SST may result in an earlier "arrival" of C. fleckeri during the dry season, possibly necessitating extension of the official Northern Territory stinger season to commence in September (currently October through to June). This short report presents data to support this hypothesis, facilitating policy makers with an environmental cue upon which changes to current stinger season can be based--prior to painful and potentially life-threatening presentations.

Efficacy of alpha-cypermethrin and lambda-cyhalothrin applications to prevent Aedes breeding in tires.

The efficacy of alpha-cypermethrin (Cyperthor) and lambda-cyhalothrin (Demand) to prevent mosquito larval colonization of water-containing receptacles was investigated using 2 differing applications in disused car tires in Darwin, Australia. Insecticide treatments were applied uniformly to the inside surfaces of 2 categories of tires: 1) dry tires that were partially filled with water 24 h after spraying and 2) wet tires partially filled with water prior to spraying. All mosquito larvae, pupae, and dead adults were collected from the treatment and control tires weekly over the 24-wk study period and were later identified to species in the laboratory. Control tires were colonized by Aedes notoscriptus in wk 2 and by Culex quinquefasciatus in wk 4. Aedes notoscriptus failed to colonize any alpha-cypermethrin-treated tires until wk 22 and did not colonize any lambda-cyhalothrin-treated tires during the 24-wk trial. Culex quinquefasciatus colonized alpha-cypermethrin and lambda-cyhalothrin-treated tires from wk 11 and wk 15, respectively. These results indicate both insecticides using either application method can prevent colonization of Ae. notoscriptus for at least 20 wk and demonstrate great potential for the prevention of breeding in receptacles for other receptacle-breeding Aedes species, such as the dengue vectors, Ae. aegypti and Ae. albopictus.