Participation in the Global Corporate Challenge®, a Four-Month Workplace Pedometer Program, Reduces Psychological Distress.

BACKGROUND: Psychological distress (stress) has been linked to an increased risk of chronic diseases and is exacerbated by a range of workplace factors. Physical activity has been shown to alleviate psychological distress. Previous pedometer-based intervention evaluations have tended to focus on physical health outcomes. This study aimed to investigate the immediate and long-term changes in psychological distress in employees based in Melbourne, Australia after their participation in a four-month pedometer-based program in sedentary workplaces. METHODS: At baseline, 716 adults (aged 40 ± 10 years, 40% male) employed in primarily sedentary occupations, voluntarily enrolled in the Global Corporate Challenge© (GCC©), recruited from 10 Australian workplaces to participate in the GCC® Evaluation Study, completed the Kessler 10 Psychological Distress Scale (K10). Of these, 422 completed the K10 at baseline, 4 months and 12 months. RESULTS: Psychological distress reduced after participation in a four-month workplace pedometer-based program, which was sustained eight months after the program ended. Participants achieving the program goal of 10,000 steps per day or with higher baseline psychological distress had the greatest immediate and sustained reductions in psychological distress. Demographic predictors of immediate reduced psychological distress (n = 489) was having an associate professional occupation, younger age, and being 'widowed, separated or divorced'. CONCLUSIONS: Participation in a workplace pedometer-based program is associated with a sustained reduction in psychological distress. Low-impact physical health programs conducted in groups or teams that integrate a social component may be an avenue to improve both physical and psychological health in the workplace.

Social Isolation and Social Support Influence Health Service Utilisation and Survival after a Cardiovascular Disease Event: A Systematic Review.

Both cardiovascular disease (CVD) and social health carry high health and economic burdens. We undertook a systematic review to investigate the association between social isolation, low social support, and loneliness with health service utilisation and survival after a CVD event among people living in Australia and New Zealand. Four electronic databases were systematically searched for the period before June 2020. Two reviewers undertook the title/abstract screen. One reviewer undertook a full-text screen and data extraction. A second author checked data extraction. Of 756 records, 25 papers met our inclusion criteria. Included studies recruited 10-12,821 participants, aged 18-98 years, and the majority were males. Greater social support was consistently associated with better outcomes on four of the five themes (discharge destination, outpatient rehabilitation attendance, rehospitalisation and survival outcomes; no papers assessed the length of inpatient stay). Positive social health was consistently associated with better discharge designation to higher independent living. As partner status and living status did not align with social isolation and social support findings in this review, we recommend they not be used as social health proxies. Our systematic review demonstrates that social health is considered in cardiac care decisions and plays a role in how healthcare is being delivered (i.e., outpatient, rehabilitation, or nursing home). This likely contributes to our finding that lower social support is associated with high-intensity healthcare services, lower outpatient rehabilitation attendance, greater rehospitalisation and poorer survival. Given our evidence, the first step to improve cardiac outcomes is acknowledging that social health is part of the decision-making process. Incorporating a formal assessment of social support into healthcare management plans will likely improve cardiac outcomes and survival. Further research is required to assess if support person/s need to engage in the risk reduction behaviours themselves for outpatient rehabilitation to be effective. Further synthesis of the impact of social isolation and loneliness on health service utilisation and survival after a CVD event is required.

Joint Food and Water Insecurity Had a Multiplicative Effect on Women's Depression in Urban Informal Settlements in Makassar, Indonesia during the COVID-19 Pandemic.

BACKGROUND: Women living in urban informal settlements may be particularly vulnerable to the detrimental effects of the COVID-19 pandemic because of increased economic and psychosocial stressors in resource-limited environments. OBJECTIVES: The objective of this study was to assess the associations between food and water insecurity during the pandemic and depression among women living in the urban informal settlements in Makassar, Indonesia. METHODS: We implemented surveys at 3 time points among women enrolled in the Revitalizing Informal Settlements and their Environments trial. Depression was measured using the Center for Epidemiologic Studies Depression Scale-10 (CESD-10) between November and December 2019 and again between February and March 2021. Food insecurity was measured using questions from the Innovation for Poverty Action's Research for Effective COVID-19 Reponses survey and water insecurity was measured using the Household Water Insecurity Experiences Short Form. Both were measured between August and September 2020. We built 3 multivariate quantile linear regression models to assess the effects of water insecurity, food insecurity, and joint food and water insecurity during the COVID-19 pandemic on CESD-10 score. RESULTS: In models with the full sample (n = 323), food insecurity (ß: 1.48; 95% CI: 0.79, 2.17), water insecurity (ß: 0.13; 95% CI: -0.01, 0.26), and joint food and water insecurity (ß: 2.40; 95% CI: 1.43, 3.38) were positively associated with CESD-10 score. In subgroup analyses of respondents for whom we had prepandemic CESD-10 scores (n = 221), joint food and water insecurity (ß: 1.96; 95% CI: 0.78, 3.15) maintained the strongest relationship with CESD-10 score. A limitation of this study is that inconsistency in respondents from households across the survey waves reduced the sample size used for this study. CONCLUSIONS: Our results find a larger association between depression and joint resource insecurity than with water or food insecurity alone, underlining the importance of addressing food and water insecurity together, particularly as they relate to women's mental health and well-being.

Implementing "from here to there": A case study of conceptual and practical challenges in implementation science.

There is a significant challenge in global health and development research that pivots on the difficulties of delivering (cost-)effective treatments or interventions that are scalable andtransferable across settings. That is, how does one deliver "true effects", proven treatments, into new settings? This is often addressed in pragmatic trials or implementation research in which one makes adjustments to the delivery of the treatment to ensure that it works here and there. In this critical analytical review, we argue that the approach mis-characterises the cause-effect relationship and fails to recognise the local, highly contextual nature of what it means to say an intervention "works". We use an ongoing randomised controlled trial (RCT)-an informal settlement redevelopment intervention in Indonesia and Fiji to reduce human exposure to pathogenic faecal contamination-as a vehicle for exploring the ideas and implications of identifying interventions that work in global health and development. We describe the highly contextualised features of the research and the challenges these would pose in attempts to generalise the results. In other words, we detail that which is frequently elided from most RCTs. As our critical lens, we us the work of American philosopher, Nancy Cartwright, who argued that research produces dappled regions of causal insights-lacunae against a backdrop of causal ignorance. Rather than learn about a relationship between a treatment and an outcome, we learn that in the right sort of context, a treatment reliably produces a particular outcome. Moving a treatment from here to there becomes, therefore, something of an engineering exercise to ensure the right factors (or "shields") are in place so the cause-effect is manifest. As a consequence, one cannot assume that comparative effectiveness or cost-effectiveness would be maintained.

Are social isolation, lack of social support or loneliness risk factors for cardiovascular disease in Australia and New Zealand? A systematic review and meta-analysis.

BACKGROUND: An international systematic review concluded that individuals with poor social health (social isolation, lack of social support or loneliness) are 30% more likely to develop coronary heart disease (CHD) and stroke. Notably, the two included Australian papers reported no association between social health and CHD or stroke. OBJECTIVE: We undertook a systematic review and meta-analysis to investigate the association between social isolation, lack of social support and loneliness and cardiovascular disease (CVD) incidence among people living in Australia and New Zealand. METHODS: Four electronic databases were systematically searched for longitudinal studies published until June 2020. Two reviewers undertook title/abstract screen and one reviewer undertook full-text screen and data extraction. Quality was assessed using the Newcastle - Ottawa Quality Assessment Scale. RESULTS: Of the 725 unique records retrieved, five papers met our inclusion criteria. These papers reported data from three Australian longitudinal datasets, with a total of 2137 CHD and 590 stroke events recorded over follow-up periods ranging from 3 to 16 years. Reports of two CHD and two stroke outcomes were suitable for meta-analysis. The included papers reported no association between social health and incidence of CVD in all fully adjusted models and most unadjusted models. CONCLUSIONS: Our systematic review is inconclusive as it identified only a few studies, which relied heavily on self-reported CVD. Further studies using medical diagnosis of CVD, and assessing the potential influence of residential remoteness, are needed to better understand the relationship between social health and CVD incidence in Australia and New Zealand.

Chronic heat stress in tropical urban informal settlements.

The health and economic impacts of extreme heat on humans are especially pronounced in populations without the means to adapt. We deployed a sensor network across 12 informal settlements in Makassar, Indonesia to measure the thermal environment that people experience inside and outside their homes. We calculated two metrics to assess the magnitude and frequency of heat stress conditions, wet bulb temperature and wet bulb globe temperature, and compared our in situ data to that collected by weather stations. We found that informal settlement residents experience chronic heat stress conditions, which are underestimated by weather stations. Wet bulb temperatures approached the uppermost limits of human survivability, and wet bulb globe temperatures regularly exceeded recommended physical activity thresholds, both in houses and outdoors. Under a warming climate, a growing number of people living informally will face potentially severe impacts from heat stress that have likely been previously overlooked or underestimated.

Study design, rationale and methods of the Revitalising Informal Settlements and their Environments (RISE) study: a cluster randomised controlled trial to evaluate environmental and human health impacts of a water-sensitive intervention in informal settlements in Indonesia and Fiji.

INTRODUCTION: Increasing urban populations have led to the growth of informal settlements, with contaminated environments linked to poor human health through a range of interlinked pathways. Here, we describe the design and methods for the Revitalising Informal Settlements and their Environments (RISE) study, a transdisciplinary randomised trial evaluating impacts of an intervention to upgrade urban informal settlements in two Asia-Pacific countries. METHODS AND ANALYSIS: RISE is a cluster randomised controlled trial among 12 settlements in Makassar, Indonesia, and 12 in Suva, Fiji. Six settlements in each country have been randomised to receive the intervention at the outset; the remainder will serve as controls and be offered intervention delivery after trial completion. The intervention involves a water-sensitive approach, delivering site-specific, modular, decentralised infrastructure primarily aimed at improving health by decreasing exposure to environmental faecal contamination. Consenting households within each informal settlement site have been enrolled, with longitudinal assessment to involve health and well-being surveys, and human and environmental sampling. Primary outcomes will be evaluated in children under 5 years of age and include prevalence and diversity of gastrointestinal pathogens, abundance and diversity of antimicrobial resistance (AMR) genes in gastrointestinal microorganisms and markers of gastrointestinal inflammation. Diverse secondary outcomes include changes in microbial contamination; abundance and diversity of pathogens and AMR genes in environmental samples; impacts on ecological biodiversity and microclimates; mosquito vector abundance; anthropometric assessments, nutrition markers and systemic inflammation in children; caregiver-reported and self-reported health symptoms and healthcare utilisation; and measures of individual and community psychological, emotional and economic well-being. The study aims to provide proof-of-concept evidence to inform policies on upgrading of informal settlements to improve environments and human health and well-being. ETHICS: Study protocols have been approved by ethics boards at Monash University, Fiji National University and Hasanuddin University. TRIAL REGISTRATION NUMBER: ACTRN12618000633280; Pre-results.

Household Water Storage Management, Hygiene Practices, and Associated Drinking Water Quality in Rural India.

Household drinking water storage is commonly practiced in rural India. Fecal contamination may be introduced at the water source, during collection, storage, or access. Within a trial of a community-level water supply intervention, we conducted five quarterly household-level surveys to collect information about water, sanitation, and hygiene practices in rural India. In a random subsample of households, we tested stored drinking water samples for Escherichia coli, concurrently observing storage and access practices. We conducted 9961 surveys and collected 3296 stored water samples. Stored water samples were frequently contaminated with E. coli (69%), and E. coli levels were the highest during the wet season. Most households contributing two or more drinking water samples had detectable E. coli in some (47%) or all (44%) samples. Predictors of stored water contamination with E. coli included consumption of river water and open defecation; consumption of reverse osmosis-treated water and safe water access practices appeared to be protective. Until households can be reached with on-premises continuous safe water supplies, suboptimal household water storage practices are likely to continue. Improvements to source water quality alone are unlikely to prevent exposure to contaminated drinking water unless attention is also given to improving household water storage, access, and sanitation practices.

A Stepped Wedge Cluster-Randomized Trial Assessing the Impact of a Riverbank Filtration Intervention to Improve Access to Safe Water on Health in Rural India.

Sustainable and low-cost methods for delivery of safe drinking water in resource-limited settings remain suboptimal, which contributes to global diarrhea morbidity. We aimed to assess whether delivery of riverbank filtration-treated water to newly installed water storage tanks (improved quality and access, intervention condition) reduced reported diarrhea in comparison to delivery of unfiltered river water (improved access alone, control condition) in rural Indian villages. We used a stepped wedge cluster-randomized trial (SW-CRT) design involving four clusters (villages). Selection criteria included village size, proximity to a river, and lack of existing or planned community-level safe water sources. All adults and children were eligible for enrollment. All villages started in the control condition and were sequentially randomized to receive the intervention at 3-month intervals. Our primary outcome was 7-day-period prevalence of self- or caregiver-reported diarrhea, measured at 3-month intervals (five time points). Analysis was by intention to treat. Because blinding was not possible, we incorporated questions about symptoms unrelated to water consumption to check response validity (negative control symptoms). We measured outcomes in 2,222 households (9,836 participants). We did not find a measurable reduction in diarrhea post-intervention (RR: 0.98 [95% CI: 0.24-4.09]); possible explanations include low intervention uptake, availability of other safe water sources, low baseline diarrheal prevalence, and reporting fatigue. Our study highlights both the difficulties in evaluating the impact of real-world interventions and the potential for an optimized SW-CRT design to address budgetary, funding, and logistical constraints inherent in such evaluations.

Effect of hygiene interventions on acute respiratory infections in childcare, school and domestic settings in low- and middle-income countries: a systematic review.

OBJECTIVES: Acute respiratory infections (ARIs) disproportionately affect those living in low- and middle-income countries (LMICs). We aimed to determine whether hygiene interventions delivered in childcare, school or domestic settings in LMICs effectively prevent or reduce ARIs. METHODS: We registered our systematic review with PROSPERO (CRD42017058239) and searched MEDLINE, EMBASE, CENTRAL, and Scopus from inception to 17 October 2017 for randomised controlled trials (RCTs) examining the impact of hygiene interventions on ARI morbidity in adults and children in community-based settings in LMICs. We stratified data into childcare, school and domestic settings and used the Grading of Recommendations Assessment, Development and Evaluation approach to assess evidence quality. RESULTS: We identified 14 cluster RCTs evaluating hand-hygiene interventions in LMICs with considerable heterogeneity in setting, size, intervention delivery and duration. We found reduced ARI-related absenteeism and illness in childcare settings (low- to moderate-quality evidence). In school settings, we found reduced ARI-related absenteeism and laboratory-confirmed influenza (moderate- to high-quality evidence), but no reduction in ARI illness (low-quality evidence). In domestic settings, we found reduced ARI illness and pneumonia amongst children in urban settlements (high-quality evidence) but not in rural settlements (low-quality evidence), and no effect on secondary transmission of influenza in households (moderate-quality evidence). CONCLUSIONS: Evidence suggests that hand-hygiene interventions delivered in childcare, school and domestic settings can reduce ARI morbidity, but effectiveness varies according to setting, intervention target and intervention compliance. Further studies are needed to develop, deliver and evaluate targeted and sustainable hygiene interventions in LMICs.

Cost of gastroenteritis in Australia: A healthcare perspective.

BACKGROUND: Acute gastroenteritis illness is a common illness that causes considerable morbidity, but current estimates of the cost to the Australian healthcare system are unknown. OBJECTIVE: To estimate the current healthcare utilisation and direct public healthcare system costs attributable to acute gastroenteritis illness in Australia. METHODS: This is an incidence-based cost-of-illness study focused on quantifying direct health care costs using a bottom-up approach. Data on general practitioner consultations, prescribed medications, diagnostic tests, specialist consultations, emergency department visits and hospital admissions were collected from national reports. RESULTS: Using 2016 prices, the estimated annual direct per capita cost of acute gastroenteritis illness was AUD$14.87 (USD$10.71), equating to AUD$20.27 (USD$14.59) per case. The estimated overall economic burden in Australia was AUD$359 million (USD$258 million; AUD$1.5 million per 100,000 people). The major contributors to this cost were hospital admissions (57.1%), emergency department visits (17.7%), and general practitioner consultations (14.0%). Children under five years of age have the highest per capita rates of acute gastroenteritis illness; however, service utilisation rates vary by age group and both young children and older adults accounted for a substantial proportion of the overall economic burden attributable to acute gastroenteritis illness. CONCLUSIONS: Although chronic diseases comprise a large cost burden on the healthcare system, acute illnesses, including acute gastroenteritis illness, also impose substantial direct healthcare system costs. Providing data on current cost estimates is useful for prioritizing public health interventions, with our findings suggesting that it would be ideal if targeted interventions to reduce hospitalisation rates among young children and older adults were available.

Alcohol, drug and related health and wellbeing issues among young people completing an online screen.

OBJECTIVE: Despite high levels of alcohol use, drug use and risky behaviors, rates of help-seeking amongst young people are typically low. This study explored the profile of young people (under the age of 25 years) completing an online screen, assessing substance use problem severity and wellbeing in comparison with adults completing the same screen, so as to inform development of better targeted approaches for this in-need population. METHODS: Between 2012 and 2014, an online alcohol and drug screen was promoted across Australia on a national online counseling service. The screen assessed severity of substance use, mental health and wellbeing. RESULTS: A total of 2939 screens were completed between December 2012 and May 2014, with 18% completed by young people. Young people reported a high severity of substance use problems (44% reported likely drug dependence) and reported significantly poorer mental health and wellbeing than adults completing the screen. This suggests that there is a population of young people in need of support who could be initially engaged through online screening. CONCLUSIONS: Online screening should be a key component of engagement strategies for adolescent and early adult help-seeking.

A tiered model of substance use severity and life complexity: Potential for application to needs-based planning.

BACKGROUND: In order to improve long-term outcomes for individuals with substance use problems, one approach is to adopt a system planning model that considers both addiction severity and life complexities. The tiered approach has been developed and tested to describe systems-level need based on levels of risk and problem severity. METHODS: An existing tiered model was modified to accommodate Australian data, incorporating substance use severity and life complexity. The hypothesis was that tiers would reflect differences in well-being amongst help seekers such that an increase in tier would be associated with a reduction in well-being, suggesting the need for more intensive (and integrated) interventions. The model was tested using 2 data sets of screening data, collected from face-to-face alcohol and other drug (AOD) service (n = 430) and online help (n = 309) seekers, drawn from a larger sample of 2,766 screens. The screen included demographic information and substance use, mental health, and quality of life measures. RESULTS: There was a significant relationship between well-being and tier ranking, suggesting that the model adequately captured elements of severity and complexity that impact on well-being. There were notable differences between the help-seeking populations with a higher proportion of online respondents allocated to lower tiers and more face-to-face respondents allocated to higher tiers. However, there was an overlap in these populations, with more than half of online respondents classified as higher tiers and one fifth of face-to-face respondents classified as lower tiers. This suggests that the model can be used both to assess unmet need in out-of-treatment groups and demand in the absence of dependence in a subpopulation of the face-to-face treatment population. CONCLUSIONS: The tiered model provides a method to understand levels of AOD treatment need and, as part of needs-based planning, may be used to optimize treatment responses and resourcing.

A probabilistic model of gastroenteritis risks associated with consumption of street food salads in Kumasi, Ghana: evaluation of methods to estimate pathogen dose from water, produce or food quality.

With a rapidly growing urban population in Kumasi, Ghana, the consumption of street food is increasing. Raw salads, which often accompany street food dishes, are typically composed of perishable vegetables that are grown in close proximity to the city using poor quality water for irrigation. This study assessed the risk of gastroenteritis illness (caused by rotavirus, norovirus and Ascaris lumbricoides) associated with the consumption of street food salads using Quantitative Microbial Risk Assessment (QMRA). Three different risk assessment models were constructed, based on availability of microbial concentrations: 1) Water - starting from irrigation water quality, 2) Produce - starting from the quality of produce at market, and 3) Street - using microbial quality of street food salad. In the absence of viral concentrations, published ratios between faecal coliforms and viruses were used to estimate the quality of water, produce and salad, and annual disease burdens were determined. Rotavirus dominated the estimates of annual disease burden (~10(-3)Disability Adjusted Life Years per person per year (DALYs pppy)), although norovirus also exceeded the 10(-4)DALY threshold for both Produce and Street models. The Water model ignored other on-farm and post-harvest sources of contamination and consistently produced lower estimates of risk; it likely underestimates disease burden and therefore is not recommended. Required log reductions of up to 5.3 (95th percentile) for rotavirus were estimated for the Street model, demonstrating that significant interventions are required to protect the health and safety of street food consumers in Kumasi. Estimates of virus concentrations were a significant source of model uncertainty and more data on pathogen concentrations is needed to refine QMRA estimates of disease burden.

Alcohol problems among migrants in substance use treatment: the role of drinking patterns in countries of birth.

Migrants' beliefs about when to seek help for alcohol problems may differ from host-country norms. We undertook an audit of 393 cases of screening in specialist alcohol and other drug services in Victoria, Australia, to examine whether alcohol problem severity at the time of help-seeking was influenced by drinking norms in countries of birth. Alcohol problem severity was measured using the Alcohol Use Disorders Identification Test, and World Health Organization per capita alcohol consumption data was used to form three categories of clients relative to Australian consumption: (1) Australian born; (2) born in low alcohol consumption countries; and (3) born in high alcohol consumption countries. Clients born in high consumption countries such as those in Europe and the UK had significantly higher levels of alcohol problem severity at intake compared with Australian-born clients and clients born in low consumption countries. This suggests that clients from high consumption countries might have delayed seeking help in line with the alcohol norms in their country of origin. Screening this group for alcohol problems in primary health care might avoid significant cumulative harm.

A probabilistic quantitative microbial risk assessment model of norovirus disease burden from wastewater irrigation of vegetables in Shepparton, Australia.

Wastewater can be an important resource for water-scarce regions of the world, but a major barrier to its use is the associated health risk. Quantitative microbial risk assessment (QMRA) is a probabilistic modeling technique used to determine the health risks from wastewater reuse, but only a handful of QMRA studies have examined the norovirus health risks from consumption of vegetables irrigated with human wastewater, even though norovirus is a, if not the most, significant microbial cause of diarrheal disease world-wide. Furthermore, the majority of these studies have focused only on risks from lettuce consumption. To meet the knowledge gap in health risks for other vegetables, a QMRA model was constructed for agricultural wastewater irrigation in the regional city of Shepparton, Australia, using fecal shedding rates to estimate norovirus concentration in raw sewage. Annual norovirus disease burden was estimated for the consumption of lettuce, broccoli, cabbage, Asian vegetables, and cucumber after irrigation with treated wastewater. Results indicate that the waste stabilization pond treatment did not have sufficient virus removal to meet the World Health Organization (WHO) threshold for acceptable level of risk for wastewater reuse, but addition of disinfection treatments provided acceptable results for consumption of cucumber and broccoli. This is the first QMRA study to incorporate virus accumulation from previous wastewater irrigation events.

Risk of norovirus gastroenteritis from consumption of vegetables irrigated with highly treated municipal wastewater--evaluation of methods to estimate sewage quality.

Quantitative microbial risk assessment was used to assess the risk of norovirus gastroenteritis associated with consumption of raw vegetables irrigated with highly treated municipal wastewater, using Melbourne, Australia as an example. In the absence of local norovirus concentrations, three methods were developed: (1) published concentrations of norovirus in raw sewage, (2) an epidemiological method using Melbourne prevalence of norovirus, and (3) an adjustment of method 1 to account for prevalence of norovirus. The methods produced highly variable results with estimates of norovirus concentrations in raw sewage ranging from 10(4) per milliliter to 10(7) per milliliter and treated effluent from 1 × 10(-3) per milliliter to 3 per milliliter (95th percentiles). Annual disease burden was very low using method 1, from 4 to 5 log10 disability adjusted life years (DALYs) below the 10(-6) threshold (0.005-0.1 illnesses per year). Results of method 2 were higher, with some scenarios exceeding the threshold by up to 2 log10 DALYs (up to 95,000 illnesses per year). Method 3, thought to be most representative of Melbourne conditions, predicted annual disease burdens >2 log10 DALYs lower than the threshold (∼ 4 additional cases per year). Sensitivity analyses demonstrated that input parameters used to estimate norovirus concentration accounted for much of the model output variability. This model, while constrained by a lack of knowledge of sewage concentrations, used the best available information and sound logic. Results suggest that current wastewater reuse behaviors in Melbourne are unlikely to cause norovirus risks in excess of the annual DALY health target.

Pathogen reduction requirements for direct potable reuse in Antarctica: evaluating human health risks in small communities.

Small, remote communities often have limited access to energy and water. Direct potable reuse of treated wastewater has recently gained attention as a potential solution for water-stressed regions, but requires further evaluation specific to small communities. The required pathogen reduction needed for safe implementation of direct potable reuse of treated sewage is an important consideration but these are typically quantified for larger communities and cities. A quantitative microbial risk assessment (QMRA) was conducted, using norovirus, giardia and Campylobacter as reference pathogens, to determine the level of treatment required to meet the tolerable annual disease burden of 10(-6) DALYs per person per year, using Davis Station in Antarctica as an example of a small remote community. Two scenarios were compared: published municipal sewage pathogen loads and estimated pathogen loads during a gastroenteritis outbreak. For the municipal sewage scenario, estimated required log10 reductions were 6.9, 8.0 and 7.4 for norovirus, giardia and Campylobacter respectively, while for the outbreak scenario the values were 12.1, 10.4 and 12.3 (95th percentiles). Pathogen concentrations are higher under outbreak conditions as a function of the relatively greater degree of contact between community members in a small population, compared with interactions in a large city, resulting in a higher proportion of the population being at risk of infection and illness. While the estimates of outbreak conditions may overestimate sewage concentration to some degree, the results suggest that additional treatment barriers would be required to achieve regulatory compliance for safe drinking water in small communities.

Microbial quality assessment of household greywater.

A monitoring program was undertaken to assess the microbial quality of greywater collected from 93 typical households in Melbourne, Australia. A total of 185 samples, comprising 75 washing machine wash, 74 washing machine rinse and 36 bathroom samples were analysed for the faecal indicator Escherichia coli. Of these, 104 were also analysed for genetic markers of pathogenic E coli and 111 for norovirus (genogroups GI and GII), enterovirus and rotavirus using RT-PCR. Enteric viruses were detected in 20 out of the 111 (18%) samples comprising 16 washing machine wash water and 4 bathroom samples. Eight (7%) samples were positive for enterovirus, twelve (11%) for norovirus genogroup GI, one (1%) for norovirus genogroup GII and another (1%) for rotavirus. Two washing machine samples contained more than one virus. Typical pathogenic E. coli were detected in 3 out of 104 (3%) samples and atypical enteropathogenic E. coli in 11 (11%) of samples. Levels of indicator E. coli were highly variable and the presence of E. coli was not associated with the presence of human enteric viruses in greywater. There was also little correlation between reported gastrointestinal illness in households and detection of pathogens in greywater.