Sands and environmental conditions impact the abundance and persistence of the fecal indicator bacteria Enterococcus at recreational beaches

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2012The marine fecal indicator Enterococcus is measured at beaches to detect fecal contamination events, and beaches are closed to bathers when Enterococcus is found to exceed the federally mandated limit. This dissertation presents evidence that beach sands are an environmental reservoir of enterococci, tests the relationship between beach sand enterococci and water quality measurements, examines how real-time environmental conditions measured at beaches can be used to better understand and predict water quality violations, and uses molecular methods to provide an alternative characterization of water and sand fecal contamination. Initially, a qPCR method was developed and applied to monitor enterococci DNA in sands. Subsequently this qPCR method was used in tandem with traditional detection of culturable enterococci in sand and water at recreational beaches that have closures every summer. One field season was spent in Maine at beaches in the Wells National Estuarine Research Reserve, where high frequency water and weather measurements are routinely collected in situ. Two field seasons were spent at the beach in Provincetown Harbor, Massachusetts, where a weather station and ADCP were deployed to characterize the environmental conditions associated with observations of elevated enterococci. All studies revealed that environmental variables were related to the distribution of enterococci in sands and water, with water temperature and tides having the strongest relationship to enterococci in water. In dry weather, elevated enterococci in sands were strongly related to the increased moisture content of sands during spring tides. These environmental variables were used in multiple linear regressions to explain a significant amount of the variation observed in environmental enterococci abundance, which notably had no relationship to molecular markers of human fecal pollution. Results suggest that under certain conditions sands can contribute bacteria to the water and that tidal cycles, which are not taken into account in monitoring schemes, can bias routine sampling.This work was funded though a fellowship and student research grant from the Woods Hole Coastal Ocean Institute, as well as a grant through the Woods Hole Ocean Venture Institute. Thanks to WHOI Academic Programs for their support of my work in the Joint Program. Additionally, this research was supported by the National Science Foundation grant OCE- 0430724, and the National Institute of Environmental Health Sciences grant P50ES012742 to the Woods Hole Center for Ocean and Human Health

Memory of a Landscape

Artist Statement Creativity is one of my strongest talents. As a visual person, I understand and interpret the world through observation and analysis. Nature intrigues me. I find it awe inspiring how the natural environment can change so dramatically day-to-day. As a result, I record my experiences and memories of landscapes and seascapes. My areas of interest are painting and computers in the arts. I am an abstract painter and my media consists of acrylic, watercolor, mixed media, and digital imagery. I create low relief and rough textures with added materials, and develop layers of paint with a palette knife. In addition, I layer gel medium transfers using my own photographs. Color is important in my work and encapsulates and expresses my feelings and memories. I use subtle color washes and add small amounts of bold color to create contrasts. This approach to coloration allows me to explore unexpected and unique combinations. I use color symbolically, such as a muted blue to display a calm and relaxed feeling that I get from experiencing nature. This also mimics the essence of sky and water. My goal is to capture the viewers’ attention and show them my response to nature in hopes that they will relate it to their own experiences

Sands and environmental conditions impact the abundance and persistence of the fecal indicator bacteria Enterococcus at recreational beaches

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), February 2012.Cataloged from PDF version of thesis.Includes bibliographical references.The marine fecal indicator Enterococcus is measured at beaches to detect fecal contamination events, and beaches are closed to bathers when Enterococcus is found to exceed the federally mandated limit. This dissertation presents evidence that beach sands are an environmental reservoir of enterococci, tests the relationship between beach sand enterococci and water quality measurements, examines how real-time environmental conditions measured at beaches can be used to better understand and predict water quality violations, and uses molecular methods to provide an alternative characterization of water and sand fecal contamination. Initially, a qPCR method was developed and applied to monitor enterococci DNA in sands. Subsequently this qPCR method was used in tandem with traditional detection of culturable enterococci in sand and water at recreational beaches that have closures every summer. One field season was spent in Maine at beaches in the Wells National Estuarine Research Reserve, where high frequency water and weather measurements are routinely collected in situ. Two field seasons were spent at the beach in Provincetown Harbor, Massachusetts, where a weather station and ADCP were deployed to characterize the environmental conditions associated with observations of elevated enterococci. All studies revealed that environmental variables were related to the distribution of enterococci in sands and water, with water temperature and tides having the strongest relationship to enterococci in water. In dry weather, elevated enterococci in sands were strongly related to the increased moisture content of sands during spring tides. These environmental variables were used in multiple linear regressions to explain a significant amount of the variation observed in environmental enterococci abundance, which notably had no relationship to molecular markers of human fecal pollution. Results suggest that under certain conditions sands can contribute bacteria to the water and that tidal cycles, which are not taken into account in monitoring schemes, can bias routine sampling.by Elizabeth Halliday.Ph.D

Comparison of bacterial communities in sands and water at beaches with bacterial water quality violations

© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 9 (2014): e90815, doi:10.1371/journal.pone.0090815.Recreational water quality, as measured by culturable fecal indicator bacteria (FIB), may be influenced by persistent populations of these bacteria in local sands or wrack, in addition to varied fecal inputs from human and/or animal sources. In this study, pyrosequencing was used to generate short sequence tags of the 16S hypervariable region ribosomal DNA from shallow water samples and from sand samples collected at the high tide line and at the intertidal water line at sites with and without FIB exceedance events. These data were used to examine the sand and water bacterial communities to assess the similarity between samples, and to determine the impact of water quality exceedance events on the community composition. Sequences belonging to a group of bacteria previously identified as alternative fecal indicators were also analyzed in relationship to water quality violation events. We found that sand and water samples hosted distinctly different overall bacterial communities, and there was greater similarity in the community composition between coastal water samples from two distant sites. The dissimilarity between high tide and intertidal sand bacterial communities, although more similar to each other than to water, corresponded to greater tidal range between the samples. Within the group of alternative fecal indicators greater similarity was observed within sand and water from the same site, likely reflecting the anthropogenic contribution at each beach. This study supports the growing evidence that community-based molecular tools can be leveraged to identify the sources and potential impact of fecal pollution in the environment, and furthermore suggests that a more diverse bacterial community in beach sand and water may reflect a less contaminated site and better water quality.This work was supported by the National Science Foundation grant OCE-0430724, and the National Institute of Environmental Health Sciences grant P0ES012742 to the Woods Hole Center for Ocean and Human Health. E. Halliday was partially supported by WHOI Academic Programs and grants from the WHOI Ocean Ventures Fund and the WHOI Coastal Ocean Institute

Impact of intermittent screening and treatment for malaria among school children in Kenya: a cluster randomised trial.

BACKGROUND: Improving the health of school-aged children can yield substantial benefits for cognitive development and educational achievement. However, there is limited experimental evidence of the benefits of alternative school-based malaria interventions or how the impacts of interventions vary according to intensity of malaria transmission. We investigated the effect of intermittent screening and treatment (IST) for malaria on the health and education of school children in an area of low to moderate malaria transmission. METHODS AND FINDINGS: A cluster randomised trial was implemented with 5,233 children in 101 government primary schools on the south coast of Kenya in 2010-2012. The intervention was delivered to children randomly selected from classes 1 and 5 who were followed up for 24 months. Once a school term, children were screened by public health workers using malaria rapid diagnostic tests (RDTs), and children (with or without malaria symptoms) found to be RDT-positive were treated with a six dose regimen of artemether-lumefantrine (AL). Given the nature of the intervention, the trial was not blinded. The primary outcomes were anaemia and sustained attention. Secondary outcomes were malaria parasitaemia and educational achievement. Data were analysed on an intention-to-treat basis. During the intervention period, an average of 88.3% children in intervention schools were screened at each round, of whom 17.5% were RDT-positive. 80.3% of children in the control and 80.2% in the intervention group were followed-up at 24 months. No impact of the malaria IST intervention was observed for prevalence of anaemia at either 12 or 24 months (adjusted risk ratio [Adj.RR]: 1.03, 95% CI 0.93-1.13, p = 0.621 and Adj.RR: 1.00, 95% CI 0.90-1.11, p = 0.953) respectively, or on prevalence of P. falciparum infection or scores of classroom attention. No effect of IST was observed on educational achievement in the older class, but an apparent negative effect was seen on spelling scores in the younger class at 9 and 24 months and on arithmetic scores at 24 months. CONCLUSION: In this setting in Kenya, IST as implemented in this study is not effective in improving the health or education of school children. Possible reasons for the absence of an impact are the marked geographical heterogeneity in transmission, the rapid rate of reinfection following AL treatment, the variable reliability of RDTs, and the relative contribution of malaria to the aetiology of anaemia in this setting. TRIAL REGISTRATION: www.ClinicalTrials.gov NCT00878007

Knowledge exchange in crisis settings: A scoping review

BACKGROUND: Public health practice and efforts to improve the social determinants of health operate within a climate characterised by multiple and intersecting crises. This includes the Covid-19 pandemic as well as more protracted crises such as climate change and persistent social inequalities that impact health. We sought to understand and compare how knowledge exchange (KE) processes occur across different crises, and how knowledge on improving social determinants of health can be utilised at times of crisis to reduce health inequalities and strengthen public systems. METHODS: We conducted a scoping review to understand how KE on improving social determinants of health can occur across different types of crises (e.g. environmental, pandemics, humanitarian). Relevant studies were identified through electronic searching of Medline, EMBASE, Global Health, Scopus and Web of Science databases. RESULTS: We identified 86 studies for inclusion in the review. Most studies concerned pandemic or environmental crises. Fewer studies explored KE during technical (e.g. nuclear), terror-related or humanitarian crises. This may reflect a limitation of the searches. Few studies assessed KE as part of longer-term responses to social and economic impacts of crises, with studies more likely to focus on immediate response or early recovery stages. Exchange of research evidence or data with policy or practice contextual knowledge was common but there was variation in the extent that lay (public) knowledge was included as part of KE processes. CONCLUSION: As ongoing crises continue with significant public health implications, KE processes should appropriately reflect the complexity inherent in crises and foreground health inequalities. Doing so could include the utilisation of systems or complexity-informed methods to support planning and evaluation of KE, a greater focus on KE to support action to address social determinants of health, and the inclusion of a plurality of knowledge-including lived experience-in planning and responding to crises

The realtionship between common patterns of prenatal alcohol exposure and the neurodevelopment of two-year old children

Background: Around 60% of women drink some alcohol while pregnant. There is conflicting evidence on the effect on the fetus of common patterns of prenatal alcohol exposure (PAE) e.g. low level or sporadic drinking. Guidelines recommend abstinence as the safest option, creating problems for those advising women who drink at these levels before pregnancy recognition or beyond. The Asking QUestions about Alcohol (AQUA) study aimed to accurately measure PAE and account for important cofactors, to reduce uncertainty about child outcomes. Method: Detailed data on PAE were prospectively collected in a pre-birth cohort of over 1500 mother/child dyads. There was also extensive data collection of predictors of child development at one and two-year's post-partum. A sub-group of children was followed up at two years of age with a neurodevelopmental assessment (Bayley III). Two-step multivariable regression analyses of an effect of PAE accounted for independent risk factors that related to 1) pregnancy, including sociodemographic, psychologic and lifestyle variables such as diet and supplement use, and 2) the postnatal care-giving environment, including breastfeeding and maternal psychological wellbeing. Results: Adjustment for independent risk factors ameliorated any putative associations between PAE and cognitive, language and motor development in 554 two year-old children spread evenly across six PAE groups. Conclusions: Assessing neurodevelopmental outcomes associated with PAE is strongly influenced by other modifiable and non-modifiable risk factors. Although we found no adverse neurodevelopmental outcomes at two years of age, follow-up will be necessary in these children when complex higher-level cognitive, language and motor skills are required

Creation of the first national linked colorectal cancer dataset in Scotland:prospects for future research and a reflection on lessons learned

Introduction: Current understanding of cancer patients, their treatment pathways and outcomes relies mainly on information from clinical trials and prospective research studies representing a selected sub-set of the patient population. Whole-population analysis is necessary if we are to assess the true impact of new interventions or policy in a real-world setting. Accurate measurement of geographic variation in healthcare use and outcomes also relies on population-level data. Routine access to such data offers efficiency in research resource allocation and a basis for policy that addresses inequalities in care provision. Objective: Acknowledging these benefits, the objective of this project was to create a population level dataset in Scotland of patients with a diagnosis of colorectal cancer (CRC). Methods: This paper describes the process of creating a novel, national dataset in Scotland. Results: In total, thirty two separate healthcare administrative datasets have been linked to provide a comprehensive resource to investigate the management pathways and outcomes for patients with CRC in Scotland, as well as the costs of providing CRC treatment. This is the first time that chemotherapy prescribing and national audit datasets have been linked with the Scottish Cancer Registry on a national scale. Conclusions: We describe how the acquired dataset can be used as a research resource and reflect on the data access challenges relating to its creation. Lessons learned from this process and the policy implications for future studies using administrative cancer data are highlighted