COVID-19: urgent actions, critical reflections and future relevance of 'WaSH': lessons for the current and future pandemics.

The COVID-19 pandemic placed hygiene at the centre of disease prevention. Yet, access to the levels of water supply that support good hand hygiene and institutional cleaning, our understanding of hygiene behaviours, and access to soap are deficient in low-, middle- and high-income countries. This paper reviews the role of water, sanitation and hygiene (WaSH) in disease emergence, previous outbreaks, combatting COVID-19 and in preparing for future pandemics. We consider settings where these factors are particularly important and identify key preventive contributions to disease control and gaps in the evidence base. Urgent substantial action is required to remedy deficiencies in WaSH, particularly the provision of reliable, continuous piped water on-premises for all households and settings. Hygiene promotion programmes, underpinned by behavioural science, must be adapted to high-risk populations (such as the elderly and marginalised) and settings (such as healthcare facilities, transport hubs and workplaces). WaSH must be better integrated into preparation plans and with other sectors in prevention efforts. More finance and better use of financing instruments would extend and improve WaSH services. The lessons outlined justify no-regrets investment by government in response to and recovery from the current pandemic; to improve day-to-day lives and as preparedness for future pandemics.

Deriving safe short-term chemical exposure values (STEV) for drinking water.

Small and brief exceedances of chemicals above their guideline values in drinking water are unlikely to cause an appreciable increased risk to human health. As a result, short-term exposure values (STEV) can be derived to help decide whether drinking water can still be supplied to consumers without adverse health risks. In this study, three approaches were applied to calculate and compare STEV for pesticides. The three approaches included basing a STEV on the acute reference dose (ARfD) (Approach 1), removing conventional attribution rates and uncertainty factors from current guideline values (Approach 2) and extrapolating 1 d and 7 d no observed adverse effect levels (NOAEL) from existing toxicity data using a log-linear regression (Approach 3). Despite being very different methods, the three approaches produced comparable STEV generally within an order of magnitude, which often overlapped with other existing short-term exposure values such as short-term no adverse response levels (SNARL) and health advisories (HA). The results show that adjusting the current guideline value using standard extrapolation factors (Approach 2) often produced the most conservative values. Approach 2 was then applied to two other chemical classes, disinfection by-products (DBPs) and cyanotoxins, demonstrating the wider applicability of the approach.

Enterocytozoon bieneusi genotypes in cats and dogs in Victoria, Australia.

BACKGROUND: Enterocytozoon bieneusi is one of the commonest microsporidians contributing to human microsporidiosis, and is frequently found in animals in various countries. However, there is limited epidemiological information on this microorganism in Australia. Here, we undertook the first molecular epidemiological study of E. bieneusi in cats and dogs in Victoria. RESULTS: Genomic DNAs were extracted from 514 individual faecal deposits from cats (n = 172) and dogs (n = 342) and then tested using PCR-based sequencing of the internal transcribed spacer (ITS) of nuclear ribosomal DNA. Four distinct genotypes (designated D, PtEb IX, VIC_cat1 and VIC_dog1) of E. bieneusi were identified in 20 of the 514 faecal samples (3.9%). Genotype D is known to have a broad host range (humans and other animals) and has a wide geographical distribution around the world. The identification of this genotype here suggests that companion animals might represent reservoir hosts that are able to transmit E. bieneusi infection to humans in Australia. A phylogenetic analysis of ITS sequence data revealed that the novel genotype VIC_cat1 is related to the known genotype type IV within Group 1, and the new genotype VIC_dog1 is linked to a contentious "Group 3", which includes genotypes reported previously in the published literature to represent Group 2 or 3. CONCLUSIONS: A future, large-scale phylogenetic study of all known E. bieneusi genotypes, including VIC_dog1, should aid in clarifying their relationships and assignment to Groups, and in the identification of new genotypes, thus assisting epidemiological investigations.

The South Australian Safe Drinking Water Act: summary of the first year of operation.

The Safe Drinking Water Act 2011 was introduced in South Australia to provide clear direction to drinking water providers on how to achieve water safety. The Act requires drinking water providers to register with SA Health and develop a risk management plan (RMP) for their water supply that includes operational and verification monitoring plans and an incident notification and communication protocol. During the first year of operation, 212 drinking water providers registered under the Act, including one major water utility and a range of small to medium sized providers in regional and remote areas of the State. Information was captured on water source(s) used and water treatment. Rainwater was the most frequently reported drinking water source (66%), followed by bore water (13%), on-supply or carting of mains water (13%), mixed source (rainwater with bore water backup) (6%) and surface water (3%). The majority of providers (91%) treated the water supply, 87% used disinfection. During the first year of operation, 16 water quality incidents were formally reported to SA Health. These included both microbial and chemical incidents. Case studies presented highlight how the RMPs are assisting drinking water providers to identify incidents of potential health concern and implement corrective actions.

Drinking rainwater: a double-blinded, randomized controlled study of water treatment filters and gastroenteritis incidence.

OBJECTIVES: We examined whether drinking untreated rainwater, a practice that is on the rise in developed countries because of water shortages, contributes to community gastroenteritis incidence. METHODS: We conducted a double-blinded, randomized controlled trial in Adelaide, Australia. Sham or active water treatment units were installed, and participants recorded incidences of illness in a health diary for 12 months. The primary outcome was highly credible gastroenteritis (HCG; characterized by a specified number of loose stools or vomiting alone or in combination with abdominal pain or nausea in a 24-hour period), and we used generalized estimating equations to account for correlations between numbers of HCG events for individuals in the same family. RESULTS: Participants reported 769 episodes during the study (0.77 episodes/person/year), with an HCG incidence rate ratio (active vs sham) of 1.05 (95% confidence interval [CI] = 0.82, 1.33). Blinding of the participants was effective (index = 0.65; 95% CI = 0.58, 0.72). CONCLUSIONS: Our results suggest that consumption of untreated rainwater does not contribute appreciably to community gastroenteritis. However, our findings may not be generalizable to susceptible and immunocompromised persons because these groups were specifically excluded from the study.

Inactivation, removal, and regrowth potential of opportunistic pathogens and antimicrobial resistance genes in recycled water systems.

With two thirds of the global population living in areas affected by water scarcity, wastewater reuse is actively being implemented or explored by many nations. There is a need to better understand the efficacy of recycled water treatment plants (RWTPs) for removal of human opportunistic pathogens and antimicrobial resistant microorganisms. Here, we used a suite of probe-based multiplex and SYBR green real-time PCR assays to monitor enteric opportunistic pathogens (EOPs; Acinetobacter baumannii, Arcobacter butzlieri, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Legionella spp., Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella Enteritidis, Streptococcus spp.) and antimicrobial resistance genes (ARGs; qnrS, blaSHV, blaTEM, blaGES, blaKPC, blaIMI, blaSME, blaNDM, blaVIM, blaIMP, blaOXA-48-like, mcr-1 and mcr-3) of key concern from an antimicrobial resistance (AMR), waterborne and foodborne disease perspective. The class 1 integron-integrase gene (intl1) was quantified as a proxy for multi-drug resistance. EOPs, intl1 and ARGs absolute abundance (DNA and RNA) and metabolic activity (RNA) was assessed through three RWTPs with differing treatment trains. Our results indicate that RWTPs produced high quality recycled water for non-potable reuse by removing >95% of EOPs and ARGs, however, subpopulations of EOPs and ARGs survived disinfection and demonstrated potential to become actively growing members of the recycled water and distribution system microbiomes. The persistence of functional intl1 suggests that significant genetic recombination capacity remains in the recycled water, along with the likely presence of multi-drug resistant bacteria. Results provide new insights into the persistence and growth of EOPs, and prevalence and removal of ARGs in recycled water systems. These data will contribute towards the emerging evidence base of AMR risks in recycled water to inform quantitative risk-based policy development regarding water recycling schemes.

Effectiveness and cost of recruitment strategies for a community-based randomised controlled trial among rainwater drinkers.

BACKGROUND: Community-based recruitment is challenging particularly if the sampling frame is not easily defined as in the case of people who drink rainwater. Strategies for contacting participants must be carefully considered to maximise generalisability and minimise bias of the results. This paper assesses the recruitment strategies for a 1-year double-blinded randomised trial on drinking untreated rainwater. The effectiveness of the recruitment strategies and associated costs are described. METHODS: Community recruitment of households from Adelaide, Australia occurred from February to July 2007 using four methods: electoral roll mail-out, approaches to schools and community groups, newspaper advertising, and other media involvement. Word of mouth communication was also assessed. RESULTS: A total of 810 callers were screened, with 53.5% eligible. Of those who were eligible and sent further information, 76.7% were willing to participate in the study and 75.1% were enrolled. The target for recruitment was 300 households, and this was achieved. The mail-out was the most effective method with respect to number of households randomised, while recruitment via schools had the highest yield (57.3%) and was the most cost effective when considering cost per household randomised (AUD$147.20). Yield and cost effectiveness were lowest for media advertising. CONCLUSION: The use of electoral roll mail-out and advertising via schools were effective in reaching households using untreated rainwater for drinking. Employing multiple strategies enabled success in achieving the recruitment target. In countries where electoral roll extracts are available to researchers, this method is likely to have a high yield for recruitment into community-based epidemiological studies.

Hypothetical scenario exercises to improve planning and readiness for drinking water quality management during extreme weather events.

Two hypothetical scenario exercises were designed and conducted to reflect the increasingly extreme weather-related challenges faced by water utilities as the global climate changes. The first event was based on an extreme flood scenario. The second scenario involved a combination of weather events, including a wild forest fire ('bushfire') followed by runoff due to significant rainfall. For each scenario, a panel of diverse personnel from water utilities and relevant agencies (e.g. health departments) formed a hypothetical water utility and associated regulatory body to manage water quality following the simulated extreme weather event. A larger audience participated by asking questions and contributing key insights. Participants were confronted with unanticipated developments as the simulated scenarios unfolded, introduced by a facilitator. Participants were presented with information that may have challenged their conventional experiences regarding operational procedures in order to identify limitations in current procedures, assumptions, and readily available information. The process worked toward the identification of a list of specific key lessons for each event. At the conclusion of each simulation a facilitated discussion was used to establish key lessons of value to water utilities in preparing them for similar future extreme events.

Molecularly imprinted drug delivery systems.

Imprinted polymers are well established as molecular recognition materials but are now being increasingly considered for active biomedical applications such as drug delivery. In this review some highlights of recent research into molecularly imprinted drug delivery and controlled release systems are presented. The key factors controlling recognition and release by imprinted polymer matrices are discussed, the current limiting factors in their properties arising from the synthesis of these materials are considered, and the future prospects for imprinted polymers in drug delivery are outlined.

Thermoresponsive polymers as gene delivery vectors: cell viability, DNA transport and transfection studies.

A range of gene delivery vectors containing the thermoresponsive polymer, poly(N-isopropylacrylamide) (PNIPAm) was evaluated for effects on cell viability, intracellular trafficking and transgene expression in C2C12 mouse muscle cells. Polymers were complexed with plasmid DNA at pH 7.4 and the ability of the resulting particles to transfect cells was assessed via confocal microscopy and protein expression studies in tissue culture. Cell viability assays indicated that these polymers were toxic at high concentrations when not complexed to DNA or at certain polymer:DNA ratios. Poly(ethyleneimine) co-polymers with side-chain grafted PNIPAm were shown to be less toxic than poly(ethyleneimine) alone or PNIPAm-co-(N,N'-dimethylaminoethylmethacrylate) linear co-polymers and the effects were concentration dependent. Confocal micrographs of labeled polymers and DNA indicated rapid cellular entry for all the complexes but expression of Green Fluorescent Protein was achieved only when the branched PEI-PNIPAm co-polymers were used as vectors. The results indicate that design of appropriate co-polymer components and overall polymer architecture can be used to mediate, and perhaps ultimately control, DNA transport and transgene expression.

Grafted thermo- and pH responsive co-polymers: surface-properties and bacterial adsorption.

A series of responsive polymers displaying pH and temperature-mediated phase changes were prepared from N-isopropylacrylamide and omega-carboxylic acid functionalised acrylamides. These polymers were grafted to surfaces and their characteristics probed by atomic force microscopy in aqueous solutions. The effects of pH and temperature induced phase transitions on the short-term adsorption of the bacteria Salmonella typhimurium and Bacillus cereus from pure cultures were assessed. Contact angle studies indicated that pH and temperature-dependent surface properties were exhibited by the graft polymer surfaces. Temperature-dependent surface morphology changes occurred through polymer graft phase transitions as observed in AFM and accompanying changes in adhesion forces underwater were found to correlate with surface properties obtained from contact angle measurements. Adsorption of S. typhimurium and B. cereus was not significantly altered as a function of pH, but attachment of both bacterial strains increased at temperatures above the polymer coil-globule transition indicating the importance of switching surface hydrophobicity in controlling short-term bacterial adsorption.

Extreme weather events: Should drinking water quality management systems adapt to changing risk profiles?

Among the most widely predicted and accepted consequences of global climate change are increases in both the frequency and severity of a variety of extreme weather events. Such weather events include heavy rainfall and floods, cyclones, droughts, heatwaves, extreme cold, and wildfires, each of which can potentially impact drinking water quality by affecting water catchments, storage reservoirs, the performance of water treatment processes or the integrity of distribution systems. Drinking water guidelines, such as the Australian Drinking Water Guidelines and the World Health Organization Guidelines for Drinking-water Quality, provide guidance for the safe management of drinking water. These documents present principles and strategies for managing risks that may be posed to drinking water quality. While these principles and strategies are applicable to all types of water quality risks, very little specific attention has been paid to the management of extreme weather events. We present a review of recent literature on water quality impacts of extreme weather events and consider practical opportunities for improved guidance for water managers. We conclude that there is a case for an enhanced focus on the management of water quality impacts from extreme weather events in future revisions of water quality guidance documents.

Thermo and pH responsive polymers as gene delivery vectors: effect of polymer architecture on DNA complexation in vitro.

Poly(N-isopropylacrylamide) (PNIPAm) co-polymers responsive to temperature and pH were prepared with side chain chemistries in order to exhibit phase transitions under physiologically relevant conditions. Fluorescence spectroscopy, gel retardation assays, dynamic light scattering and atomic force microscopy were used to characterize the binding of plasmid DNA to these materials and to control polymers poly(ethyleneimine) (PEI) and poly(ethyleneimine)-octanamide. Complexes of plasmid DNA with thermoresponsive cationic polymers containing PNIPAm displayed variations in gel retardation behaviour above and below polymer phase transition temperatures, with a high molecular weight linear cationic PNIPAm co-polymer forming complexes with reduced affinity above LCST whereas a branched PEI-PNIPAm co-polymer bound with higher affinity above the PNIPAm phase transition. The thermoresponsive polymers also exhibited changes in particle morphology across the same temperature ranges with polymer DNA complexes prepared at N/P ratios of 2:1 generating spherical particles varying in radius between 30-70 nm at 25 degrees C and 60-100 nm at 40-45 degrees C. The transport of DNA within these complexes to cell nuclei was demonstrated to occur within 24 h in tissue culture via confocal microscopy, and low level transfection of mouse muscle cells by a reporter gene encoding green fluorescent protein was achieved with the branched thermoresponsive PEI-PNIPAm conjugate.

Not all radiolucencies of the jaw require enucleation: a case of brown tumour.

We describe a case of brown tumour from primary hyperparathyroidism, which presented with radiolucency in the jaw. It was treated by parathyroidectomy, which resulted in complete resolution of the lytic lesion without any surgery to the jaw. It is important to be aware of endocrine causes of a common radiological sign to avoid unnecessary local surgical intervention.

Investigation of spa pools associated with lung disorders caused by Mycobacterium avium complex in immunocompetent adults.

Three cases of Mycobacterium avium complex-related lung disorders were associated with two poorly maintained spa pools by genotypic investigations. Inadequate disinfection of the two spas had reduced the load of environmental bacteria to less than 1 CFU/ml but allowed levels of M. avium complex of 4.3 x 10(4) and 4.5 x 10(3) CFU/ml. Persistence of the disease-associated genotype was demonstrated in one spa pool for over 5 months until repeated treatments with greater than 10 mg of chlorine per liter for 1-h intervals eliminated M. avium complex from the spa pool. A fourth case of Mycobacterium avium complex-related lung disease was associated epidemiologically but not genotypically with another spa pool that had had no maintenance undertaken. This spa pool contained low numbers of mycobacteria by smear and was culture positive for M. avium complex, and the nonmycobacterial organism count was 5.2 x 10(6) CFU/ml. Public awareness about the proper maintenance of private (residential) spa pools must be promoted by health departments in partnership with spa pool retailers.