Climate change and water-related infectious diseases

Background: Water-related, including waterborne, diseases remain important sources of morbidity and mortality worldwide, but particularly in developing countries. The potential for changes in disease associated with predicted anthropogenic climate changes make water-related diseases a target for prevention. Methods: We provide an overview of evidence on potential future changes in water-related disease associated with climate change. Results: A number of pathogens are likely to present risks to public health, including cholera, typhoid, dysentery, leptospirosis, diarrhoeal diseases and harmful algal blooms (HABS). The risks are greatest where the climate effects drive population movements, conflict and disruption, and where drinking water supply infrastructure is poor. The quality of evidence for water-related disease has been documented. Conclusions: We highlight the need to maintain and develop timely surveillance and rapid epidemiological responses to outbreaks and emergence of new waterborne pathogens in all countries. While the main burden of waterborne diseases is in developing countries, there needs to be both technical and financial mechanisms to ensure adequate quantities of good quality water, sewage disposal and hygiene for all. This will be essential in preventing excess morbidity and mortality in areas that will suffer from substantial changes in climate in the future

An Assessment of the Impact of Climate Change on Human Health in New Hampshire

Climate change threatens human health in many ways. The negative impacts of climate change on human health are likely to increase in both magnitude and frequency as the climate continues to change in response to ever increasing global emissions of heat-trapping gases released from a variety of human activities.The Centers for Disease Control and Prevention (CDC) Building Resilience Against Climate Effects (BRACE) framework provides guidance to states and cities to develop strategies and programs to confront the health implications of climate change. This report serves to address Steps 1 and 2 of the BRACE framework via an assessment of past and future climate change across New Hampshire combined with an assessment of the impact of climate change on human health. A key component of the BRACE framework is building resilience. In public health, resilience is a measure of a community’s ability to utilize available resources to respond to, withstand, and recover from adverse situations. More generally, people think of resilience as the ability to recover, persist, or thrive amid change. The New Hampshire Climate and Health Workgroup has tentatively developed the following definition: Resilience is the ability and capacity to anticipate, prepare for, respond to, and recover from significant threats with minimum damage to human health and well-being, the economy, and the environment. The importance of the way we plan our built environment—including land use, transportation, and water management decisions, as well as how we interact with our natural environment and preserve its life-supporting functions—must be emphasized as pivotal points of intersection as we develop climate adaptation strategies. Notably, a resilience-based approach to climate change adaptation should align with New Hampshire’s transformative State Health Improvement Plan. That plan underscores the importance of cross-sector collaboration and coordinated strategies to address the social and environmental determinants of health. These strategies not only support healthy communities for all New Hampshire residents, but they are also critically important for reducing health care costs and reducing the burden of disease

Consumer trust and confidence: Some recent ideas in the literature

This is a post-print version of the article. The official published version can be accessed from the link below - © IWA Publishing 2008This paper reflects on two recent debates in the consumer literature on trust that have implications for consumer relations in the water industry. The first concerns an important yet seldom made distinction between trust and confidence. The second concerns when and how trust is related to acceptance of, for example, new tariffs or new technologies, and it challenges the conventional view that trust is usually a precursor of acceptance. New conceptual models addressing these debates are described and their implications for future water-related consumer research are discussed as are potential implications for industry relationships with consumers

Development of Low-Cost Impedimetric Biosensors for Clinical Diagnostics and Water Testing

The World Health Organization (WHO) estimates that waterborne diseases alone account for over 3.4 million deaths per year. With such a high mortality, the need to provide a fast and accurate means of identifying the cause of the microbial infection is fundamental to the quality of care and paramount to public health. In resource-poor settings a shortage of clinics pose a major problem, as patients are required to travel long distances, many of which cannot afford the return trip to retrieve their test results. Between visits most clinics are limited to microscopic analyses, telehistology, or media-based metabolic tests, which can take as long as a week. In addition, less-monitored water supplies in these areas become breeding grounds for bacteria that can affect an entire community. Overall the developing world lacks the advanced pathogen detection and water treatment technology of first world countries. Due to the costs and training associated with such technology, it is not feasible for the developing world to house these advancements. Recently there has been a push to provide affordable devices for these countries. Although diagnostics have made improvements in recent years, there is still a need for quick and more affordable tests to identify microbial infectious agents. The basis of the proposed technology allows the individual to identify the presence of a waterborne pathogen within 10-15 minutes, much less than the traditional time-consuming cell culture technique. Scientific literature confirms that lectins, specifically sugar-binding plant proteins, have been observed to agglutinate with a variety of pathogens. With this binding as a foundation, the group has successfully designed impedimetric biosensors that respond via a change in resistance when foreign pathogens are introduced. Proof of concept testing has confirmed the technology\u27s ability to detect for the presence of pathogens at clinically relevant concentrations. In the future this impedimetric technology can be used for the development of two novel devices: 1. a low-cost point-of-care clinical diagnostic for measuring and identifying the presence of pathogenic agents and 2. a low-cost in-line system for automated remote testing of biological contamination in water systems

Waterborne disease outbreak investigation toolkit

The purpose of this toolkit is to assist state and local health departments in conducting waterborne disease outbreak investigations.Disease outbreaks that involve transmission through water can present unique challenges due to the numerous ways that individuals interact with water. To address these unique challenges, this toolkit describes similarities among many types of waterborne disease outbreak investigations based on best practices and experiences of epidemiologists at state and local health departments. This toolkit lays out a framework for a waterborne disease investigation and consolidates resources that may be useful to direct investigation activities.Additional sections are available for specific situations that may require additional techniques, resources, or investigation activities.CS321158Publication date from document properties.waterborne-disease-outbreak-toolkit-h.pdf2021966

A new pathogen transmission mechanism in the ocean: the case of sea otter exposure to the land-parasite Toxoplasma gondii.

Toxoplasma gondii is a land-derived parasite that infects humans and marine mammals. Infections are a significant cause of mortality for endangered southern sea otters (Enhydra lutris nereis), but the transmission mechanism is poorly understood. Otter exposure to T. gondii has been linked to the consumption of marine turban snails in kelp (Macrocystis pyrifera) forests. It is unknown how turban snails acquire oocysts, as snails scrape food particles attached to surfaces, whereas T. gondii oocysts enter kelp beds as suspended particles via runoff. We hypothesized that waterborne T. gondii oocysts attach to kelp surfaces when encountering exopolymer substances (EPS) forming the sticky matrix of biofilms on kelp, and thus become available to snails. Results of a dietary composition analysis of field-collected snails and of kelp biofilm indicate that snails graze the dense kelp-biofilm assemblage composed of pennate diatoms and bacteria inserted within the EPS gel-like matrix. To test whether oocysts attach to kelp blades via EPS, we designed a laboratory experiment simulating the kelp forest canopy in tanks spiked with T. gondii surrogate microspheres and controlled for EPS and transparent exopolymer particles (TEP - the particulate form of EPS). On average, 19% and 31% of surrogates were detected attached to kelp surfaces covered with EPS in unfiltered and filtered seawater treatments, respectively. The presence of TEP in the seawater did not increase surrogate attachment. These findings support a novel transport mechanism of T. gondii oocysts: as oocysts enter the kelp forest canopy, a portion adheres to the sticky kelp biofilms. Snails grazing this biofilm encounter oocysts as 'bycatch' and thereby deliver the parasite to sea otters that prey upon snails. This novel mechanism can have health implications beyond T. gondii and otters, as a similar route of pathogen transmission may be implicated with other waterborne pathogens to marine wildlife and humans consuming biofilm-feeding invertebrates

Waterborne Pathogens: A Critical Assessment of Methods, Results and Data Analysis

Humans harbour a variety of pathogens that are often transmitted from other animal species. A few are localized in tropical areas, but most enteric pathogens are present everywhere on the planet and they travel with their hosts to distant locations. Several of these microorganisms are transmitted by water that has been contaminated by fecal matter, whereas some are normally found in water but, given an opportunity, will cause disease (i.e., opportunistic pathogens). While waterborne outbreaks have been reported for many pathogens, assessing the proportion of the disease burden to a specific route and pathogen has proven quite elusive. Surveillance of disease in populations, even when actively done, is very inaccurate as it often gathers data on the most acute cases that are only a very small proportion of the true number of infected individuals. There are several issues discussed herein, focusing on the needs and gaps linked to waterborne pathogen monitoring. The benefits and weaknesses of current and emerging methodologies are discussed, in addition to the appropriateness of allocating resources to waterborne pathogen monitoring. The most critical gap is the lack of validation of most methods used in environmental microbiology for the detection of pathogens. Data generated by various laboratories are currently extremely difficult to compare and cannot serve as the basis for risk assessment or management. The issue of laboratory capacity is also raised, within the context of the availability of trained personnel, the application of QA/QC protocols, and accreditation on a national level. In closing, needs are identified for informed communication of the risks of waterborne pathogens, the training of highly qualified personnel, and the development and standardization of methods that will ultimately enhance water safety and public health protection.De nombreux microorganismes pathogènes entériques affectent l’homme et certains peuvent être acquis d’autres espèces animales. Certains sont spécifiques aux régions tropicales, mais la plupart des microorganismes entériques sont les mêmes partout sur la planète, voyageant avec leurs hôtes aux coins les plus reculés. Ils se retrouvent dans l’eau contaminée par les matières fécales excrétées. D’autres sont indigènes au milieu hydrique et sont des opportunistes, causant la maladie chez les individus susceptibles. Par la surveillance des épidémies associées à l’eau, on a pu facilement identifier ceux qui sont importants en santé publique. Il est cependant beaucoup plus difficile d’attribuer quelle part du fardeau de la maladie peut être attribuée à une voie d’exposition spécifique. La surveillance de la maladie dans les populations, même lorsqu’elle est active, est très imprécise puisqu’elle ne collige que les données sur les cas les plus graves, soit une faible partie du nombre réel d’individus infectés. À des fins de santé publique, il y a plusieurs aspects, incluant des besoins et des manques, associés au suivi des microorganismes pathogènes dans l’eau. Les bénéfices et faiblesses des méthodes courantes et émergentes doivent être présentés dans un contexte d’appropriation de ressources au suivi des microorganismes pathogènes dans l’environnement. Le simple fait de vouloir analyser des échantillons pour y détecter des microorganismes pathogènes implique des éléments que trop de chercheurs connaissent mal. Les conséquences publiques, légales, politiques et économiques ont été mises en évidence lors de plusieurs événements partout dans le monde, mais plus récemment à Sydney en Australie. Une erreur de laboratoire a conduit à la détection (fausse) de parasites (Cryptosporidium) dans l’eau potable : cette erreur a coûté plus de 37 millions de dollars et affecté trois millions de résidents sans qu’aucune infection ne soit observée. Les producteurs d’eau veulent connaître le niveau de pollution de leur eau d’approvisionnement afin de déterminer le niveau approprié de traitement : comme les méthodes sont imprécises, la marge d’erreur est très grande. Les recommandations présentes sont plutôt dirigées vers des paramètres physico-chimiques (turbidité, mesure de désinfectant en continu, etc.) et des plans de sécurité lesquels sont facilement applicables, mesurables et fiables.Les méthodes actuelles de détection des microorganismes pathogènes sont peu fiables et leur diversité dans les différents laboratoires rend l’interprétation difficile. Le manque le plus important reste le peu de validation de la plupart des méthodes de détection des microorganismes pathogènes en microbiologie environnementale. Les données fournies par des laboratoires différents ne peuvent donc être facilement comparées et ne peuvent servir à faire des évaluations de risque ou de la gestion de risque. En général, peu de laboratoires offrent de telles analyses, le personnel qualifié est rare, les protocoles de QA/QC sont rarement présents et il n’y a aucune accréditation nationale. La formation de personnel hautement qualifié et le développement de méthodes standardisées ne pourront donc ultimement que mieux servir la santé publique. Les méthodes actuelles utilisées dans un cadre bien défini de certains projets de recherche écologiques commencent à porter fruit. Les données de positionnement géographique, climatologiques et microbiologiques doivent être évaluées afin que la qualité des données produites par les modèles écologiques soit valide. En résumé, les informations acquises sur la présence des microorganismes pathogènes dans les eaux de surface sont utiles mais ne peuvent être utilisées que si elles sont validées. Les laboratoires effectuant les analyses devront être accrédités et devront utiliser des méthodes standardisées si nous voulons comparer les données fournies. Ce n’est qu’à ce moment que l’analyse quantitative du risque microbiologique pourra se faire. Cette nouvelle approche est en émergence au niveau international et les modèles proposés doivent utiliser des données précises. Au Canada, l’Agence de santé publique du Canada s’intéresse à cette nouvelle approche. En l’absence de mesures précises, les chercheurs et les agences de contrôle doivent utiliser les indicateurs de traitement et de contamination fécale pour s’assurer de l’innocuité de l’eau de consommation. Alors que les protocoles d’analyse sont bien définis pour ces paramètres, ceux requis pour les microorganismes pathogènes ne sont pas encore établis. Or, des analyses occasionnelles ou mal ciblées ne sont pas valides pour des fins de santé publique.Les organisations internationales, telles l’Organisation pour la coopération et le développement économique (OCDE) et l’Organisation mondiale de la santé (OMS), s’intéressent aux méthodes récentes qui allient la biologie moléculaire et la bioinformatique pour obtenir des réponses rapides et fiables sur la contamination des eaux. Ce sera par l’éducation et la communication que les risques pourront être établis et que nous pourrons en informer correctement le public en général, la communauté scientifique, les agences gouvernementales et les producteurs d’eau. Les recherches futures devront répondre aux questions de méthodologie, sensitivité, spécificité, et surtout aux questions de valeur prédictive des résultats de détection de microorganismes pathogènes

Intestinal antimicrobial gene expression: impact of micronutrients in malnourished adults during a randomized trial.

BACKGROUND: Because both micronutrients and antimicrobial peptides protect against diarrhea, we looked for an effect on intestinal antimicrobial peptide gene expression during a randomized controlled trial of multiple micronutrient (MM) supplementation. METHODS: Consenting adults (n=287) in Lusaka, Zambia, were randomized to receive a daily MM supplement or placebo and were followed up for 3.3 years, with a crossover after 2 years. Intestinal biopsy samples were obtained at annual intervals, and messenger RNA of the intestinal antimicrobial peptides human alpha defensin (HD) 5, HD6, human beta-defensin (hBD) 1, hBD2, and LL-37 were quantified by real-time reverse-transcriptase polymerase chain reaction. Samples were also obtained during diarrhea episodes and after convalescence. RESULTS: There was no effect overall of treatment allocation. However, in malnourished adults (body mass index < or =18.5), HD5 mRNA was increased by 0.8 log transcripts/microg total RNA in MM recipients, compared with HD5 mRNA in placebo recipients (P=.007). During diarrhea, HD5 expression was reduced by 0.8 log transcripts in placebo recipients (P=.02) but was not reduced in MM recipients, nor was it reduced after the crossover. Correlations between HD5 and nutritional status were found that were sex-specific but not explained by serum leptin or adiponectin concentrations. CONCLUSIONS: Micronutrient supplementation was associated with up-regulation of HD5 only in malnourished adults. Interactions between antimicrobial gene expression and nutritional status may help to explain the increased risk of infection in individuals with malnutrition