A planetary health model for reducing exposure to faecal contamination in urban informal settlements: Baseline findings from Makassar, Indonesia.

Background: The intense interactions between people, animals and environmental systems in urban informal settlements compromise human and environmental health. Inadequate water and sanitation services, compounded by exposure to flooding and climate change risks, expose inhabitants to environmental contamination causing poor health and wellbeing and degrading ecosystems. However, the exact nature and full scope of risks and exposure pathways between human health and the environment in informal settlements are uncertain.

Monitoring of diverse enteric pathogens across environmental and host reservoirs with TaqMan array cards and standard qPCR: a methodological comparison study.

Background: Multiple bacteria, viruses, protists, and helminths cause enteric infections that greatly impact human health and wellbeing. These enteropathogens are transmited via several pathways through human, animal, and environmental reservoirs. Individual qPCR assays have been extensively used to detect enteropathogens within these types of samples, whereas the TaqMan array card (TAC), which allows simultaneous detection of multiple enteropathogens, has only previously been validated in human clinical samples.

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.

Barriers and Enablers to Intervention Uptake and Health Reporting in a Water Intervention Trial in Rural India: A Qualitative Explanatory Study.

Consumption of unsafe drinking water contributes to the global disease burden, necessitating identification and implementation of effective, acceptable, and sustainable water interventions in resource-limited settings. In a quantitative stepped-wedge cluster randomized trial of a community-based water intervention in rural India, we identified low rates of intervention uptake and reported diarrhea. To better understand and explain these findings, we performed a qualitative study examining barriers and enablers to intervention uptake and health reporting using the COM-B model, where capabilities, opportunities, and motivators interact to generate behavior.

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).

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.

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.

Burden of Disease Attributed to Waterborne Transmission of Selected Enteric Pathogens, Australia, 2010.

AbstractUniversal access to safe drinking water is a global priority. To estimate the annual disease burden of campylobacteriosis, nontyphoidal salmonellosis, cryptosporidiosis, giardiasis, and norovirus attributable to waterborne transmission in Australia, we multiplied regional World Health Organization (WHO) estimates of the proportion of cases attributable to waterborne transmission by estimates of all-source disease burden for each study pathogen. Norovirus was attributed as causing the most waterborne disease cases (479,632; 95% uncertainty interval [UI]: 0-1,111,874) followed by giardiasis and campylobacteriosis.

Protocol for a cluster randomised stepped wedge trial assessing the impact of a community-level hygiene intervention and a water intervention using riverbank filtration technology on diarrhoeal prevalence in India.

Introduction: Diarrhoea is a leading cause of death globally, mostly occurring as a result of insufficient or unsafe water supplies, inadequate sanitation and poor hygiene. Our study aims to investigate the impact of a community-level hygiene education program and a water quality intervention using riverbank filtration (RBF) technology on diarrhoeal prevalence.

Methods And Analysis: We have designed a stepped wedge cluster randomised trial to estimate the health impacts of our intervention in 4 rural villages in Karnataka, India.

Measuring water ingestion from spray exposures.

Characterisation of exposure levels is an essential requirement of health risk assessment; however for water exposures other than drinking, few quantitative exposure data exist. Thus, regulatory agencies must use estimates to formulate policy on treatment requirements for non-potable recycled water. We adapted the use of the swimming pool chemical cyanuric acid as a tracer of recreational water ingestion to permit detection of small water volumes inadvertently ingested from spray exposures.

Variability in 24 hour excretion of cyanuric acid: implications for water exposure assessment.

Cyanuric acid (CYA) excretion in urine has been used to estimate the volume of water ingested during swimming and other recreational activities in outdoor pools containing this chemical. These estimates of water ingestion are based on the assumption of 100% excretion within 24 hours, but the supporting evidence for this is scant. While adapting this methodology to investigate other water ingestion scenarios, we observed a high degree of variability in cyanuric acid excretion among experimental subjects, with over 25% of individuals excreting less than 80% of an ingested dose.

Adoption of a microbial health-based target for Australian drinking water regulation.

The health-based targets of 1 in 10,000 for infection and 10(-6) disability adjusted life years (DALYs) per person per year are increasingly being considered, or have already been adopted, to define microbial safety targets for water. The aim of this paper is to convey information about how these two targets compare by converting each of the target values to a common metric. The metric chosen for viral (rotavirus and norovirus) and protozoan (Cryptosporidium) reference pathogens is the estimated maximum number of annual drinking water-associated cases of acute diarrhoeal disease tolerated.

Evolution of regulatory targets for drinking water quality.

The last century has been marked by major advances in the understanding of microbial disease risks from water supplies and significant changes in expectations of drinking water safety. The focus of drinking water quality regulation has moved progressively from simple prevention of detectable waterborne outbreaks towards adoption of health-based targets that aim to reduce infection and disease to a level well below detection limits at the community level. This review outlines the changes in understanding of community disease and waterborne risks that prompted development of these targets, and also describes their underlying assumptions and current context.

Disease burden of selected gastrointestinal pathogens in Australia, 2010.

Objective: To estimate and compare disease burden attributable to six gastrointestinal pathogens (norovirus, rotavirus, Campylobacter, non-typhoidal Salmonella, Giardia, and Cryptosporidium) in Australia, 2010.

Methods: We estimated the number of acute gastroenteritis (AGE) cases and deaths, disability-adjusted life years (DALYs), and DALY/case for each pathogen. We included AGE cases that did not require medical care.

Advice to risk assessors modeling viral health risk associated with household graywater.

Quantitative microbial risk assessment (QMRA) is a valuable tool that can be used to predict the risk associated with human exposure to specific microbial contaminants in water sources. The transparency inherent in the QMRA process benefits discussions between multidisciplinary teams because members of such teams have different expertise and their confidence in the risk assessment output will depend upon whether they regard the selected input data and assumptions as being suitable and/or plausible. Selection of input data requires knowledge of the availability of appropriate data sets, the limitations of using a particular data set, and the logic of using alternative approaches.

Using disability-adjusted life years to set health-based targets: a novel use of an established burden of disease metric.

Following the 1990 Global Burden of Disease (GBD) study, Disability-Adjusted Life Years (DALYs) have been used widely to quantify the population health burden of diseases and to prioritise and evaluate the impact of specific public health interventions. In the context of the recent release of the 2010 GBD study, we explore the novel use of DALYS to determine health-based targets (HBTs). As with the more traditional use of DALYs, the main advantage of using DALYs as HBTs is the ability to account for differential disease severity, identify the most appropriate public health interventions, and measure the positive and negative outcomes of these interventions.

A probabilistic model of norovirus disease burden associated with greywater irrigation of home-produced lettuce in Melbourne, Australia.

The reuse of domestic greywater has become common in Australia, especially during periods of extreme drought. Greywater is typically used in a raw, untreated form, primarily for landscape irrigation, but more than a quarter of greywater users irrigate vegetable gardens with the water, despite government advice against this practice. Greywater can be contaminated with enteric pathogens and may therefore pose a health risk if irrigated produce is consumed raw.

Comparison of response rates and cost-effectiveness for a community-based survey: postal, internet and telephone modes with generic or personalised recruitment approaches.

Background: Epidemiological research often requires collection of data from a representative sample of the community or recruitment of specific groups through broad community approaches. The population coverage of traditional survey methods such as mail-outs to residential addresses, and telephone contact via public directories or random-digit-dialing is declining and survey response rates are falling. There is a need to explore new sampling frames and consider multiple response modes including those offered by changes in telecommunications and internet technology.

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.

Health status of residents of an urban dual reticulation system.

Background: Households in dual reticulation developments are supplied with recycled water from sewage effluent for some non-potable purposes, and conventional tap water for other uses. Adverse health effects from recycled water exposure are considered unlikely; however, no epidemiological studies have been undertaken to assess the public health impact of such exposures.

Methods: We compared the health status of residents of a dual reticulation housing development with residents of an adjacent conventional water supply area by assessing consultation rates with primary-care physicians for three conditions considered plausibly related to recycled water exposure (gastroenteritis, respiratory complaints and dermal complaints), and two conditions considered unrelated to water exposures (urinary tract infections and musculoskeletal complaints).

Collecting household water usage data: telephone questionnaire or diary?

Background: Quantitative Microbial Risk Assessment (QMRA), a modelling approach, is used to assess health risks. Inputs into the QMRA process include data that characterise the intensity, frequency and duration of exposure to risk(s). Data gaps for water exposure assessment include the duration and frequency of urban non-potable (non-drinking) water use.

The Australian Electoral Commission Roll has good utility for 'niche' household recruitment in population health studies.

Objective: To investigate the recruitment of 'niche' household populations, defined by their household characteristics and/or water supply type for health studies.

Methods: The Australian Electoral Commission (AEC) database was used to recruit households for participation in two health-related studies, the first, a recycled water usage study and the second, an epidemiological study investigating household rainwater use.

Results: The AEC database facilitated the identification and recruitment of households using a particular water supply from among the general household population.

Transfer rates of enteric microorganisms in recycled water during machine clothes washing.

Approximately 15% of overall Australian household water usage is in the laundry; hence, a significant reduction in household drinking water demand could be achieved if potable-quality water used for clothes washing is replaced with recycled water. To investigate the microbiological safety of using recycled water in washing machines, bacteriophages MS-2 and PRD-1, Escherichia coli, and Cryptosporidium parvum oocysts were used in a series of experiments to investigate the transfer efficiency of enteric microorganisms from washing machine water to objects including hands, environmental surfaces, air, and fabric swatches. By determining the transference efficiency, it is possible to estimate the numbers of microorganisms that the user will be exposed to if recycled water with various levels of residual microorganisms is used in washing machines.