2016 Annex to the Model Aquatic Health Code : scientific rationale. 2nd edition, July 2016.

Posted on 07/18/2016This information is distributed solely as guidance for the purpose of assisting state and local health departments, aquatic facility inspection programs, building officials, the aquatics sector, and other interested parties in improving the health and safety at public aquatic facilities. This document does not address all health and safety concerns associated with its use. It is the responsibility of the user of this document to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to each use.The Model Aquatic Health Code (MAHC) is a set of voluntary guidelines based on science and best practices that were developed to help programs that regulate public aquatic facilities reduce the risk of disease, injury, and drowning in their communities. The MAHC is a leap forward from the Centers for Disease Control and Prevention\u2019s (CDC) operational and technical manuals published in 1959, 1976, and 1981 and a logical progression of CDC\u2019s Healthy Swimming Program started in 2001. The 2016 MAHC underscores CDC\u2019s long-term involvement and commitment to improving aquatic health and safety. The MAHC guidance document stemmed from concern about the increasing number of pool-associated outbreaks starting in the mid-1990s. Creation of the MAHC was the major recommendation of a 2005 national workshop held in Atlanta, Georgia charged with developing recommendations to reduce these outbreaks. Federal, state, and local public health officials and the aquatics sector formed an unprecedented collaboration to create the MAHC. The MAHC will be regularly updated using input from a national stakeholder partnership called the Council for the Model Aquatic Health Code (CMAHC). The CMAHC was formed to keep the MAHC up to date and current with the latest advances in the aquatics industry while also responding to public health reports of disease and injury. The partnership hopes this truly will lead to achieving the MAHC vision of \u201cHealthy and Safe Aquatic Experiences for Everyone\u201d in the future.The 2016 MAHC utilized the first time CMAHC conference process to collect, assess, and relay MAHC Change Request recommendations to CDC. The first CMAHC Vote on the Code Biennial Conference was held October 6-7, 2015 in Phoenix Arizona, a little over one year after CDC\u2019s release of the 2014 MAHC, 1st Edition. CDC utilized CMAHC\u2019s input to revise the MAHC and plans to utilize the CMAHC conference process to update future versions of the MAHC.CS264311B2016-mahc-annex-final.pdfSupersede

Analysis of Research on the Effects of Improved Water, Sanitation, and Hygiene on the Health of People Living with HIV and AIDS and Programmatic Implications

This paper reviews the existing scientific and programmatic evidence, raises WASH issues in the HIV and AIDS context that need further study to build the evidence base, assesses current WASH guidance through a review of national HIV/AIDS guidelines from five African countries, and identifies programmatic implications that home-based care programs and the WASH sectors must consider

2016 Annex to the Model Aquatic Health Code : scientific rationale with changes highlighted. 2nd edition, July 2016.

Posted on 07/18/2016This information is distributed solely as guidance for the purpose of assisting state and local health departments, aquatic facility inspection programs, building officials, the aquatics sector, and other interested parties in improving the health and safety at public aquatic facilities. This document does not address all health and safety concerns associated with its use. It is the responsibility of the user of this document to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to each use.The Model Aquatic Health Code (MAHC) is a set of voluntary guidelines based on science and best practices that were developed to help programs that regulate public aquatic facilities reduce the risk of disease, injury, and drowning in their communities. The MAHC is a leap forward from the Centers for Disease Control and Prevention\ue2\u20ac\u2122s (CDC) operational and technical manuals published in 1959, 1976, and 1981 and a logical progression of CDC\ue2\u20ac\u2122s Healthy Swimming Program started in 2001. The 2016 MAHC underscores CDC\ue2\u20ac\u2122s long-term involvement and commitment to improving aquatic health and safety. The MAHC guidance document stemmed from concern about the increasing number of pool-associated outbreaks starting in the mid-1990s. Creation of the MAHC was the major recommendation of a 2005 national workshop held in Atlanta, Georgia charged with developing recommendations to reduce these outbreaks. Federal, state, and local public health officials and the aquatics sector formed an unprecedented collaboration to create the MAHC. The MAHC will be regularly updated using input from a national stakeholder partnership called the Council for the Model Aquatic Health Code (CMAHC). The CMAHC was formed to keep the MAHC up to date and current with the latest advances in the aquatics industry while also responding to public health reports of disease and injury. The partnership hopes this truly will lead to achieving the MAHC vision of \ue2\u20ac\u153Healthy and Safe Aquatic Experiences for Everyone\ue2\u20ac? in the future.The 2016 MAHC utilized the first time CMAHC conference process to collect, assess, and relay MAHC Change Request recommendations to CDC. The first CMAHC Vote on the Code Biennial Conference was held October 6-7, 2015 in Phoenix Arizona, a little over one year after CDC\ue2\u20ac\u2122s release of the 2014 MAHC, 1st Edition. CDC utilized CMAHC\ue2\u20ac\u2122s input to revise the MAHC and plans to utilize the CMAHC conference process to update future versions of the MAHC.CS264311B2016-mahc-annex-with-changes-highlighted.pd

Salmonella and tomatoes

Outbreak information linking fresh tomato fruit to illnesses is reviewed in this chapter. While tomato fruit appear to support substantial proliferation of certain serovars of Salmonella enterica, detection of this pathogen in tomato plants prior to harvest is rare, and reports of Salmonella existence in tomato fruit still attached to field-grown plants are virtually non-existent. The bacterium is sensitive to UV and can be outcompeted by the native phytomicrobiota, which may explain its absence in field-grown crops. However, the persistence of certain serovars in fields and ponds of certain production areas is noted. Together with evidence of bacteria becoming internalized in tomato fruit during crop development likely through natural apertures, the presence of S. enterica in and around production fields suggests that an unusual weather event could lead to Salmonella contamination of fruit prior to harvest. The bacterium appears physiologically adaptive toward proliferation in tomato fruit. Once inside tomatoes, Salmonella is capable of sensing the availability of nutrients and physiological state of the fruit and differentially regulates specific genes. However, because Salmonella is an efficient nutrient scavenger, removal of multiple metabolic and regulatory genes was required to reduce its fitness within the fruit. Plants do not appear to recognize human enterics as pathogens, and their defenses treat them as endophytes

Salmonella and tomatoes

Outbreak information linking fresh tomato fruit to illnesses is reviewed in this chapter. While tomato fruit appear to support substantial proliferation of certain serovars of Salmonella enterica, detection of this pathogen in tomato plants prior to harvest is rare, and reports of Salmonella existence in tomato fruit still attached to field-grown plants are virtually non-existent. The bacterium is sensitive to UV and can be outcompeted by the native phytomicrobiota, which may explain its absence in field-grown crops. However, the persistence of certain serovars in fields and ponds of certain production areas is noted. Together with evidence of bacteria becoming internalized in tomato fruit during crop development likely through natural apertures, the presence of S. enterica in and around production fields suggests that an unusual weather event could lead to Salmonella contamination of fruit prior to harvest. The bacterium appears physiologically adaptive toward proliferation in tomato fruit. Once inside tomatoes, Salmonella is capable of sensing the availability of nutrients and physiological state of the fruit and differentially regulates specific genes. However, because Salmonella is an efficient nutrient scavenger, removal of multiple metabolic and regulatory genes was required to reduce its fitness within the fruit. Plants do not appear to recognize human enterics as pathogens, and their defenses treat them as endophytes

UVA-LED disinfect hydroponic solution

The number of plant factories in which crops are cultivated in an artificial environment has been increasing every year. In cultivation techniques involving hydroponics, plants are supplied with a circulating nutrient solution, which can become contaminated by pathogens that can propagate and spread throughout plant factories. Therefore, strategies to disinfect hydroponic nutrient solutions are needed. In this study, we developed a new disinfection device equipped with an ultraviolet A (UVA) light emitting diode (LED) that can be used to disinfect hydroponic nutrient solutions in plant factories. We first evaluated the basic disinfection capability of the device and then estimated its bactericidal effect in a small scale model system. The log survival ratio was related to UVA irradiation fluence and the volume of nutrient solution. From the assay results, we devised a kinetics equation to describe the relationship between nutrient solution volume, log survival ratio, and UVA fluence. Together our results show that UVA irradiation could be used to disinfect hydroponic nutrient solutions, and the derived kinetics equations can be used to determine optimal conditions, such as nutrient solution volume, UVA irradiation, and killing activity, to develop devices that disinfect hydroponic nutrient solutions

Risk evaluation of drinking water distribution system contamination due to operation and maintenance activities

Pathogenic microorganisms responsible for waterborne disease outbreaks -- Mechanisms of microorganisms introduction into distribution systems -- Impact of disinfectant residual on microbial intrusion -- Risks related to accidental intrusion of microorganisms in distribution systems -- Research objectives and methodology -- Critical review of the literature on distirbution system intrusion -- Efficacy o fdisinfectant residual against microbial intrusion in distribution systems; a review of existing studies -- The fate of microorganisms experimentally introduced into drinking water systems -- Laboratory -- or bench-scale systems -- Pilot-scale systems -- Full-scale test distirbution system -- Discussion : what can be learned from these experiments? Assessing the effect of distribution system O & M on water quality -- Impact of water mian repairs on water quality -- Negative pressure events and water quality -- Integration of data was found useful to explain water quality variations -- Loss in system's physical integvrity : field assessment of the impact on water quality -- Loss in system's hydraulic integrity : field assessment of the impact on water quality -- Benefits for the water industry

Towards a predictive framework for microbial management in drinking water systems

The application of DNA sequencing-based approaches to drinking water microbial ecology has revealed the presence of an abundant and diverse microbiome; therefore, the possibility of harnessing drinking water (DW) microbial communities is an attractive prospect in order to address some of the current and emerging challenges in the sector. Moreover, these multiple challenges suggest that a shift in the DW sector, from a “reactive and sanctioning” paradigm to a “due diligence/proactive” based approach may be the key in identifying potentially adverse events. My research project has focused on the characterization of the microbial ecology of full-scale DW systems using DNA sequencing-based approaches, with the aim of exploring how the obtained insights could be applied into a predictive/proactive microbial management approach. To achieve this aim, I have focused my efforts on sampling multiple full-scale DW systems in order to elucidate the impacts of: (i) methodological variation and (ii) system properties on DW microbial communities, using a combination of bioinformatics, molecular biology, microbial ecology and multivariate statistical analyses. Regarding methodological variation, I have elucidated the impacts of sample replication, PCR replication, sample volume and sampling flow rate on the structure and membership of DW microbial communities. This was the first time that methodological variation was explored in the DW context, and the first time that multi-level replication has been tested and applied in DW molecular microbial ecology. Moreover, my findings have direct implications for the design of future sampling campaigns. Regarding system properties, I have shown that microbial communities in DW distribution systems (DWDSs) undergo diurnal variation, and therefore are linked to water use patters/hydraulics in the systems. I have also shown that sampling locations in the same distribution system are similar, with OTUs found across sampling locations at different relative abundance and detection frequency levels. An assessment of the impact of source water type and treatment processes showed that disinfection is a key treatment step for community composition and functional potential, and that several genes related to protection against chlorine/oxygen species are overabundant in chlorinated and chloraminated systems. Looking to the future, I believe that the application of a “toolbox” of techniques is key in shifting towards a proactive approach in DW management, that multidisciplinary synergies hold the possibility of changing the way in which DW systems have been studied and managed for over 100 years

Flow-enhanced detection of biological pathogens using piezoelectric microcantilever arrays

The piezoelectric microcantilever sensor (PEMS) is an all-electrical resonant oscillator biosensor system capable of in-situ and label-free detection. Immobilized receptors on the sensor surface enable real-time electrical measurement of the resonance frequency shift due to the binding of target antigens to the surface. With silane-based insulation methods and bifunctional linker antibody immobilization schemes, it is wellsuited for applications in sensitive, specific detection of biological pathogens with limits of detection on the order of relevant lethal infectious dosage concentrations. Initial PEMS implementation demonstrated biodetection of Bacillus anthracis (BA) spores at a concentration of just 36 total spores in 0.8 mL of liquid. While these results are exciting, concerns that cross reactivity between the antibody and closely related species of the target pathogens cast doubts on the usefulness of any antibody-based assays in terms of the specificity of pathogen detection.The goal of this dissertation is to develop the PEMS biosensor as a viable antibody-based assay for in-situ, label-free, water-borne pathogen detection with better limits of detection than current antibody-based methods as well as high sensitivity and specificity, by exploring array PEMS detection and specificity augmentation by engineered fluidics. In the detection of BA spores, controlled fluid flow experiments in an 8 mm wide flow channel at flow rates ranging from 0 to 14 mL/min led to a determination of optimal flow rates for discriminatory detection of BA spores among close cousins: B. cereus (BC), B. thuringiensis (BT) and B. subtilis (BS). It is shown that the detection signal of all such spores first increased with an increasing flow rate. The detection signals of BC, BT and BS eventually diminished with the increasing flow rate as the force of the flow overcame the interaction force of the BC, BT, and BS spores with the sensor surface. The optimal flow rate was determined to be 14 mL/min at which detection signals of BC, BT, and BS all fell to within the noise level of the sensor, while the detection BA was still nearly optimal. As a result, it was deduced that the interaction forces of BC, BT, and BS were about 100 pN.Design and implementation of array sensing systems enabled real-time simultaneous redundant biosensor assays and concurrent background determination by a reference PEMS. By virtue of this advance in PEMS technology, successful real-time detection of just 10 BA spores/mL was achieved and step-wise, single Cryptosporidium parvum (CP) oocyst detection at 0.1 oocysts/mL was accomplished with resonance frequency step-wise shifts of 290 Hz and signal to noise ratios greater than 5 per instance of oocyst detection. It was found that, in a 19 mm wide flow channel, optimal single oocyst detection efficiency was achieved at 2 mL/min, while optimal discrimination of CP from C. muris (CM) oocysts was achieved at 5 mL/min. At this flow rate the detection signal of CP was close to optimal with a signal to noise ratio of 5 per step-wise shift and that of CM was close to the noise level. The interaction forces of CP and CM oocysts with the biosensor surfaces were deduced to be 110 and 70 pN, respectively.Ph.D., Materials Science and Engineering -- Drexel University, 200

Growth and flow cytometric monitoring of bacteria in drinking water

Bacteria are omnipresent, also in our drinking water. This is unavoidable but should not be a reason to worry. It is better to understand them, to be able to control and predict their behavior. In a first section of this research, fundamental factors affecting bacterial presence in drinking water were studied. Transparent exopolymer particles were monitored as a possible biofilm promoter, but their importance in Flemish drinking waters appeared to be limited. In addition, the factors governing growth or survival of intruding bacteria in drinking water were studied. It appeared that next to the available nutrients, the present indigenous microbial community was crucial. Routine monitoring of bacteria in drinking water asks for performant tools. Therefore, the second section optimized the use of flow cytometry as a high-throughput monitoring tool and it was shown that bacterial analysis could be done fast and precise. A third and final section was conducted in close collaboration with drinking water industry and searched for additional applications for flow cytometry, deviating from routine monitoring. The tool was successfully applied for providing fast information during rinsing of major supply pipes and for a quick screening of bacterial growth in a local drinking water network