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"Moe, Christine"
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Vomiting as a Symptom and Transmission Risk in Norovirus Illness: Evidence from Human Challenge Studies
by
Kirby, Amy E.
,
Moe, Christine L.
,
Streby, Ashleigh
in
Adult
,
Biology and Life Sciences
,
Caliciviridae Infections - epidemiology
2016
In the US, noroviruses are estimated to cause 21 million cases annually with economic losses reaching $2 billion. Outbreak investigations frequently implicate vomiting as a major transmission risk. However, little is known about the characteristics of vomiting as a symptom or the amount of virus present in emesis.
Emesis samples and symptomology data were obtained from previous norovirus human challenge studies with GI.1 Norwalk virus, GII.2 Snow Mountain virus, and a pilot study with GII.1 Hawaii virus. Viral titers in emesis were determined using strain-specific quantitative RT-PCR. In all four studies, vomiting was common with 40-100% of infected subjects vomiting at least once. However, only 45% of subjects with vomiting also had diarrhea. Most of the emesis samples had detectable virus and the mean viral titers were 8.0 x 105 and 3.9 x 104 genomic equivalent copies (GEC)/ml for GI and GII viruses, respectively (p = 0.02). Sample pH was correlated with GII.2 Snow Mountain virus detection.
Half of all subjects with symptomatic infection experienced vomiting and the average subject shed 1.7 x 108 GEC in emesis. Unlike shedding through stool, vomiting is more likely to result in significant environmental contamination, leading to transmission through fomites and airborne droplets. This quantitative data will be critical for risk assessment studies to further understand norovirus transmission and develop effective control measures. The correlation between sample pH and virus detection is consistent with a single site of virus replication in the small intestine and stomach contents becoming contaminated by intestinal reflux. Additionally, the frequency of vomiting without concurrent diarrhea suggests that epidemiology studies that enroll subjects based on the presence of diarrhea may be significantly underestimating the true burden of norovirus disease.
Journal Article
Quantitative assessment of fecal contamination in multiple environmental sample types in urban communities in Dhaka, Bangladesh using SaniPath microbial approach
2019
Rapid urbanization has led to a growing sanitation crisis in urban areas of Bangladesh and potential exposure to fecal contamination in the urban environment due to inadequate sanitation and poor fecal sludge management. Limited data are available on environmental fecal contamination associated with different exposure pathways in urban Dhaka. We conducted a cross-sectional study to explore the magnitude of fecal contamination in the environment in low-income, high-income, and transient/floating neighborhoods in urban Dhaka. Ten samples were collected from each of 10 environmental compartments in 10 different neighborhoods (4 low-income, 4 high-income and 2 transient/floating neighborhoods). These 1,000 samples were analyzed with the IDEXX-Quanti-Tray technique to determine most-probable-number (MPN) of E. coli. Samples of open drains (6.91 log10 MPN/100 mL), surface water (5.28 log10 MPN/100 mL), floodwater (4.60 log10 MPN/100 mL), produce (3.19 log10 MPN/serving), soil (2.29 log10 MPN/gram), and street food (1.79 log10 MPN/gram) had the highest mean log10 E. coli contamination compared to other samples. The contamination concentrations did not differ between low-income and high-income neighborhoods for shared latrine swabs, open drains, municipal water, produce, and street foodsamples. E. coli contamination levels were significantly higher (p <0.05) in low-income neighborhoods compared to high-income for soil (0.91 log10 MPN/gram, 95% CI, 0.39, 1.43), bathing water (0.98 log10 MPN/100 mL, 95% CI, 0.41, 1.54), non-municipal water (0.64 log10 MPN/100 mL, 95% CI, 0.24, 1.04), surface water (1.92 log10 MPN/100 mL, 95% CI, 1.44, 2.40), and floodwater (0.48 log10 MPN/100 mL, 95% CI, 0.03, 0.92) samples. E. coli contamination were significantly higher (p<0.05) in low-income neighborhoods compared to transient/floating neighborhoods for drain water, bathing water, non-municipal water and surface water. Future studies should examine behavior that brings people into contact with the environment and assess the extent of exposure to fecal contamination in the environment through multiple pathways and associated risks.
Journal Article
Variation in exposure in neighborhoods of Dhaka, Bangladesh across different environmental pathways: The influence of human behavior on fecal exposure in urban environments
2026
Poor sanitation and fecal sludge management contribute to fecal contamination in Dhaka's urban environment. An exposure assessment through ten environmental pathways was conducted using the SaniPathTM tool to understand the exposure to fecal contamination.
Data collection took place from 25/04/2017 to 30/01/2018 in ten neighborhoods: four low-income, four high-income, and two transient/floating neighborhoods. A total of 1000 environmental samples were analyzed using the IDEXX QuantiTray/2000 method with IDEXX-Colilert-24® media for the most probable number (MPN) of E. coli. Additionally, 823 household surveys, 28 community surveys, and 35 school surveys on exposure-related behaviors were conducted. Bayesian methods were used to estimate monthly E. coli exposure levels and population exposure percentages for each environmental pathway in the neighborhoods.
Findings revealed that children (aged 5-12 years) in low-income and floating neighborhoods had more frequent contact with most environmental pathways (at least one contact per week or month), except surface water, compared to children in high-income neighborhoods. Dominant exposure pathways varied by neighborhood and socioeconomic status. Children experienced higher estimated monthly fecal exposure doses than adults, primarily through ingestion of contaminated municipal water (all community average = 59.2% of population exposed, either adults or children) and contact with open drains (52.3%) and surface waters (29.0%). Adults were mainly exposed via contaminated municipal water (54.2%), produce (87.0%), and street food (64.5%), which were frequently consumed.
These results highlight substantial risks of fecal exposure across diverse urban settings in Dhaka. Integrated, multisectoral, and sustainable approaches are critical to reduce exposure and protect public health. Behavior change interventions targeting children and caregivers can further mitigate these risks and help ensure long-term public health improvements.
Journal Article
The SaniPath Exposure Assessment Tool: A quantitative approach for assessing exposure to fecal contamination through multiple pathways in low resource urban settlements
by
Moe, Christine L.
,
Wang, Yuke
,
Perez, Eddy
in
Bathing
,
Bayesian analysis
,
Biology and Life Sciences
2020
Inadequate sanitation can lead to exposure to fecal contamination through multiple environmental pathways and can result in adverse health outcomes. By understanding the relative importance of multiple exposure pathways, sanitation interventions can be tailored to those pathways with greatest potential public health impact. The SaniPath Exposure Assessment Tool allows users to identify and quantify human exposure to fecal contamination in low-resource urban settings through a systematic yet customizable process. The Tool includes: a project management platform; mobile data collection and a data repository; protocols for primary data collection; and automated exposure assessment analysis. The data collection protocols detail the process of conducting behavioral surveys with households, school children, and community groups to quantify contact with fecal exposure pathways and of collecting and analyzing environmental samples for E. coli as an indicator of fecal contamination. Bayesian analyses are used to estimate the percentage of the population exposed and the mean dose of fecal exposure from microbiological and behavioral data. Fecal exposure from nine pathways (drinking water, bathing water, surface water, ocean water, open drains, floodwater, raw produce, street food, and public or shared toilets) can be compared through a common metric-estimated ingestion of E. coli units (MPN or CFU) per month. The Tool generates data visualizations and recommendations for interventions designed for both scientific and lay audiences. When piloted in Accra, Ghana, the results of the Tool were comparable with that of an in-depth study conducted in the same neighborhoods and highlighted consumption of raw produce as a dominant exposure pathway. The Tool has been deployed in nine cities to date, and the results are being used by local authorities to design and prioritize programming and policy. The SaniPath Tool is a novel approach to support public-health evidence-based decision-making for urban sanitation policies and investments.
Journal Article
Wastewater surveillance of pathogens can inform public health responses
by
Moe, Christine L.
,
Stevenson, Bradley S.
,
Driver, Erin M.
in
692/699/255
,
692/700/478/174
,
Biomarkers
2022
Wastewater monitoring has been used to identify SARS-CoV-2 outbreaks and track new variants. This sentinel system should be expanded to monitor other pathogens and boost public health preparedness.
Journal Article
Urban sanitation coverage and environmental fecal contamination: Links between the household and public environments of Accra, Ghana
by
Wellington, Nii
,
Moe, Christine L.
,
Berendes, David M.
in
Adenoviridae - isolation & purification
,
Analysis
,
Biology and Life Sciences
2018
Exposure to fecal contamination in public areas, especially in dense, urban environments, may significantly contribute to enteric infection risk. This study examined associations between sanitation and fecal contamination in public environments in four low-income neighborhoods in Accra, Ghana. Soil (n = 72) and open drain (n = 90) samples were tested for E. coli, adenovirus, and norovirus. Sanitation facilities in surveyed households (n = 793) were categorized by onsite fecal sludge containment (\"contained\" vs. \"uncontained\") using previous Joint Monitoring Program infrastructure guidelines. Most sanitation facilities were shared by multiple households. Associations between spatial clustering of household sanitation coverage and fecal contamination were examined, controlling for neighborhood and population density (measured as enumeration areas in the 2010 census and spatially matched to sample locations). E. coli concentrations in drains within 50m of clusters of contained household sanitation were more than 3 log-units lower than those outside of clusters. Further, although results were not always statistically significant, E. coli concentrations in drains showed consistent trends with household sanitation coverage clusters: concentrations were lower in or near clusters of high coverage of household sanitation facilities-especially contained facilities-and vice versa. Virus detection in drains and E. coli concentrations in soil were not significantly associated with clustering of any type of household sanitation and did not exhibit consistent trends. Population density alone was not significantly associated with any of the fecal contamination outcomes by itself and was a significant, yet inconsistent, effect modifier of the association between sanitation clusters and E. coli concentrations. These findings suggest clustering of contained household sanitation, even when shared, may be associated with lower levels of fecal contamination within drains in the immediate public domain. Further research is needed to better quantify these relationships and examine impacts on health.
Journal Article
Norovirus Vaccine Against Experimental Human GII.4 Virus Illness: A Challenge Study in Healthy Adults
by
Barrett, Jill
,
Vinjé, Jan
,
Moe, Christine L.
in
Adjuvants, Immunologic - administration & dosage
,
Adolescent
,
Adult
2015
Background. Vaccines against norovirus, the leading cause of acute gastroenteritis, should protect against medically significant illness and reduce transmission. Methods. In this randomized, double-blind, placebo-controlled trial, 18-to 50-year-olds received 2 injections of placebo or norovirus GI. 1/GII. 4 bivalent vaccine-like particle (VLP) vaccine with 3-O-desacyl-4'-monophosphoryl lipid A (MPL) and alum. Participants were challenged as inpatients with GII. 4 virus (4400 reverse transcription polymerase chain reaction [RT-PCR] units), and monitored for illness and infection. Results. Per protocol, 27 of 50 (54.0%) vaccinees and 30 of 48 (62.5%) controls were infected. Using predefined illness and infection definitions, vaccination did not meet the primary endpoint, but self-reported cases of severe (0% vaccinees vs 8.3% controls; P = .054), moderate or greater (6.0% vs 18.8%; P = .068), and mild or greater severity of vomiting and/or diarrhea (20.0% vs 37.5%; P = .074) were less frequent. Vaccination also reduced the modified Vesikari score from 7.3 to 4.5 (P = .002). Difficulties encountered were low norovirus disease rate, and inability to define illness by quantitative RT-PCR or further antibody rise in vaccinees due to high vaccine-induced titers. By day 10,11 of 49 (22.4%) vaccinees were shedding virus compared with 17 of 47 (36.2%) placebo recipients (P = .179). Conclusions. Bivalent norovirus VLP vaccine reduced norovirus-related vomiting and/or diarrhea; field efficacy studies are planned.
Journal Article
Application of the behaviour-centred design to understand facilitators and deterrents of hand hygiene among healthcare providers: findings from a formative phase of a cluster randomised trial in the Kampala Metropolitan area
2024
Background
Hand hygiene is known to reduce healthcare-associated infections. However, it remains suboptimal among healthcare providers. In this study, we used the Behaviour-centered Design approach to explore the facilitators and deterrents to hand hygiene among healthcare providers in the Kampala Metropolitan area, Uganda.
Methods
We conducted a formative qualitative study as part of a cluster randomised trial in 19 healthcare facilities (HCFs). The study used 19 semi-structured and 18 key informant interviews to collect data on hand hygiene status and facilitators and deterrents of hand hygiene. Research assistants transcribed verbatim and used a thematic framework aided by Nvivo 14.0. to undertake analysis. We used thick descriptions and illustrative quotes to enhance the credibility and trustworthiness of our findings.
Results
About 47.4% of the HCFs had sufficient hand hygiene infrastructure, and 57.9% did not report total compliance with hand hygiene during patient care. The physical facilitator for hand hygiene was the presence of constant reminders such as nudges, while the biological included the frequency of patient contact and the nature of clinical work. The only biological deterrent was the heavy workload in HCFs. The executive brain facilitators included knowledge of workplace health risks, infection prevention and control (IPC) guidelines, and a positive attitude. A negative attitude was the executive brain deterrent to hand hygiene. Recognition, rewards, and fear of infections were the only motivated brain facilitators. Behavioural setting facilitators included proximity to functional hand hygiene infrastructure, the existence of active IPC committees, good leadership, and the availability of a budget for hand hygiene supplies. Behavioural setting deterrents included the non-functionality and non-proximity to hand hygiene infrastructure and inadequate supplies.
Conclusions
The study revealed low compliance with hand hygiene during the critical moments of patient care and inadequacy of hand hygiene infrastructure. The deterrents to hand hygiene included a heavy workload, negative attitude, inadequate supplies, non-functionality, and long distance to hand washing stations. Facilitators included constant reminders, fear of infections, frequency of patient contact and nature of clinical work, positive attitude, knowledge of IPC guidelines, recognition and reward, good leadership, availability of budgets for hand hygiene supplies, availability and proximity to hand hygiene supplies and infrastructure and active IPC committees.
Trial registration
ISRCTN Registry with number ISRCTN98148144. The trial was registered on 23/11/2020.
Journal Article
Correlation of SARS-CoV-2 in Wastewater and Individual Testing Results in a Jail, Atlanta, Georgia, USA
2024
Institution-level wastewater-based surveillance was implemented during the COVID-19 pandemic, including in carceral facilities. We examined the relationship between COVID-19 diagnostic test results of residents in a jail in Atlanta, Georgia, USA (average population ≈2,700), and quantitative reverse transcription PCR signal for SARS-CoV-2 in weekly wastewater samples collected during October 2021‒May 2022. The jail offered residents rapid antigen testing at entry and periodic mass screenings by reverse transcription PCR of self-collected nasal swab specimens. We aggregated individual test data, calculated the Spearman correlation coefficient, and performed logistic regression to examine the relationship between strength of SARS-CoV-2 PCR signal (cycle threshold value) in wastewater and percentage of jail population that tested positive for COVID-19. Of 13,745 nasal specimens collected, 3.9% were COVID-positive (range 0%-29.5% per week). We observed a strong inverse correlation between diagnostic test positivity and cycle threshold value (r = -0.67; p<0.01). Wastewater-based surveillance represents an effective strategy for jailwide surveillance of COVID-19.
Journal Article
Quantitative multi-pathway assessment of exposure to Escherichia coli for infants in Rural Ethiopia
by
Paro, Fevi
,
Moe, Christine L.
,
Schieber, Elizabeth
in
Biology and Life Sciences
,
Ecology and Environmental Sciences
,
Economic aspects
2025
In low- and middle-income countries (LMICs), enteric infections pose a significant threat to children’s health. However, understanding the specifics of when, where, and how young children in LMICs are exposed to enteric pathogens and the roles of animal reservoirs, environmental media, and human hosts play during exposure remains limited. This study systematically evaluates infants’ exposure to E. coli through various pathways in the rural Haramaya woreda of Ethiopia. Between June 2021 and June 2022, we conducted over 1300 hours of structured behavioral observations on 79 infants when aged 4–8 months (Timepoint 1) and 11–15 months (Timepoint 2). Enumerators recorded the infant’s behavior related to exposure, including when and where it occurred, using a data collection system for behavioral data (Countee). Concurrently, we collected 1338 environmental samples from key contact interfaces between infants, other people, and the environment to test for E. coli . We used a competing hazard model for duration-based behaviors, an inhomogeneous Poisson point process model for frequency-based behaviors, and a left-censored lognormal distribution model for E. coli contamination levels. The behavioral and environmental information was then integrated into an agent-based exposure model framework to quantify the exposure to E. coli through different pathways. The infant behavior, which altered the relative importance of different exposure pathways, changed as children grew older. Notably, we observed increased rates of touching behavior (e.g., touching fomites) and soil-pica, increased consumption of solid food, and more time spent on the bare ground at Timepoint 2. The major sources of exposure to E. coli were food and breastfeeding at Timepoint 1 and food and soil at Timepoint 2. This study provides insights for interventions to minimize infants’ risk of exposure to fecal indicator bacteria, E. coli , and subsequent risk of enteric infections, including improved food handling practices, enhanced personal hygiene for breastfeeding caregivers, and education on the risk of soil-pica.
Journal Article