Al Dufour

Assessing Microbial Safety of Drinking Water: Improving Approaches and Methods

Inadequate drinking water quality and poor sanitation have remained the worlds major causes of preventable morbidity and mortality. In 1996 the OECD called for concerted action to improve the assessment and management of the worlds sources of drinking water. This guidance document seeks to respond to this call. It is the product of a shared initiative between the OECD and the World Health Organization. It is a state-of-the-art review that will contribute to the revisions of the WHOs Guidelines for Drinking Water Quality. Assessing Microbial Safety Of Drinking-water has elements of both revolution and evolution. It is revolutionary in that it supports a rapidly emerging approach for a broader, system-wide management perspective. This is based on a risk management framework that has evolved from the traditional indicator concept to include multiple parameters and where consideration is also given to tolerable risk, water quality targets and public health status. This title belongs to WHO Drinking-water Quality Series. . ISBN: 9781780405872 (eBook) ISBN: 9781843390367 (Print)

Waterborne Zoonoses: Identification, Causes and Control

Zoonoses are caused by microorganisms of animal origin that can also infect humans. Apart from human-to-human transmitted pathogens, they are the microorganisms of greatest concern in regard to threats to drinking-water and ambient water safety, now and in the future. A significant number of emerging and re-emerging waterborne zoonotic pathogens have been recognized over recent decades. SARS, E. coli O157:H7, and Cryptosporidium provide examples of zoonoses with waterborne routes of transmission. Developed from an expert workshop of 29 scientists convened by the World Health Organization and the United States Environmental Protection Agency (USEPA), Waterborne Zoonoses: Identification, Causes and Control provides a critical assessment of current knowledge about waterborne zoonoses and identifies strategies and research needs for controlling future emerging waterborne zoonoses. This book provides guidance to agriculturists, veterinarians, worldwide health agencies and water providers to anticipate potential future waterborne disease problems and to determine whether current practices will be protective or whether new approaches need to be deployed to better protect the health of both humans and animals. This title belongs to WHO Emerging Issues in Water & Infectious Disease Series. . ISBN: 9781780405865 (eBook) ISBN: 9781843390589 (Print)

Statistical approaches to developing a multiplex immunoassay for determining human exposure to environmental pathogens.

There are numerous pathogens that can be transmitted through water. Identifying and understanding the routes and magnitude of exposure or infection to these microbial contaminants are critical to assessing and mitigating risk. Conventional approaches of studying immunological responses to exposure or infection such as Enzyme-Linked Immunosorbent Assays (ELISAs) and other monoplex antibody-based immunoassays can be very costly, laborious, and consume large quantities of patient sample. A major limitation of these approaches is that they can only be used to measure one analyte at a time. Multiplex immunoassays provide the ability to study multiple pathogens simultaneously in microliter volumes of samples. However, there are several challenges that must be addressed when developing these multiplex immunoassays such as selection of specific antigens and antibodies, cross-reactivity, calibration, protein-reagent interferences, and the need for rigorous optimization of protein concentrations. In this study, a Design of Experiments (DOE) approach was used to optimize reagent concentrations for coupling selected antigens to Luminex™ xMAP microspheres for use in an indirect capture, multiplex immunoassay to detect human exposure or infection from pathogens that are potentially transmitted through water. Results from Helicobacter pylori, Campylobacter jejuni, Escherichia coli O157:H7, and Salmonella typhimurium singleplexes were used to determine the mean concentrations that would be applied to the multiplex assay. Cut-offs to differentiate between exposed and non-exposed individuals were determined using finite mixed modeling (FMM). The statistical approaches developed facilitated the detection of Immunoglobulin G (IgG) antibodies to H. pylori, C. jejuni, Toxoplasma gondii, hepatitis A virus, rotavirus and noroviruses (VA387 and Norwalk strains) in fifty-four diagnostically characterized plasma samples. Of the characterized samples, the detection rate was 87.5% for H. pylori, and 100% for T. gondii assays and 89% for HAV. Further, the optimized multiplex assay revealed exposure/infection to several other environmental pathogens previously uncharacterized in the samples.

Animal Waste, Water Quality and Human Health

Domestic animals contaminate recreational waters and drinking-water sources with excreta and pathogens; but this threat to public health is inadequately understood and is insufficiently addressed in regulations. More than 85% of the worlds faecal wastes is from domestic animals such as poultry, cattle, sheep and pigs. These animals harbor zoonotic pathogens that are transported in the environment by water, especially runoff. However little information exists on health effects associated with exposure to this potential hazard to human health; and water standards focused on control of human fecal contamination do reflect the contribution of non-human fecal contamination to risk. Does compliance with current monitoring practices using microbial indicators provide protection against animal and bird sources of fecal contamination? Prepared with contributions from a group of international experts, Animal Waste, Water Quality and Human Health considers microbial contamination from domestic animal and bird sources and explores the health hazards associated with this microbial contamination and approaches to protecting public health. Animal Waste, Water Quality and Human Health will be of interest to regulators with responsibility for recreational waters, drinking water quality and water reuse; policymakers working in water quality, public health and agriculture; decision makers responsible for livestock management; and scientists and practitioners concerned with many affected subjects. This title belongs to WHO Water Series . Co-Published with World Health Organisation (WHO) WHO & United States Environmental Protection Agency (USEPA) ISBN: 9781780401249 (eBook) ISBN: 9781780401232 (Print)