Risk Of Acute Gastrointestinal Illness Research Articles

Estimating the risk of gastrointestinal illness associated with drinking tap water in Norway: a prospective cohort study

BackgroundThe delivery of safe drinking water has high public health relevance, as reflected in the Sustainable Development Goals (SDG6). Several precautionary actions have reduced the burden associated with infectious diseases in high-income countries; however, pollution in source waters, inadequate disinfection, and premise plumbing, along with an increased awareness that intrusion in the drinking water distribution system, represents risk factors for gastrointestinal illness linked to consume of drinking water. Sporadic cases of waterborne infections are expected to be underreported since a sick person is less likely to seek healthcare for a self-limiting gastrointestinal infection. Hence, knowledge on the true burden of waterborne diseases is scarce. The primary aim with the present study was to estimate the risk of gastrointestinal illness associated with drinking tap water in Norway.MethodsWe conducted a 12-month prospective cohort study where participants were recruited by telephone interview after invitation based on randomised selection. A start up e-survey were followed by 12 monthly SMS questionnaires to gather information on participants characteristics and drinking tap water (number of 0.2L glasses per day), incidence, duration and symptoms associated with gastrointestinal illness. Associations between the exposure of drinking tap water and the outcome of risk of acute gastrointestinal illness (AGI) were analysed with linear mixed effects models. Age, sex, education level and size of the drinking water supply were identified as potential confounders and included in the adjusted model.ResultsIn total, 9,946 persons participated in this cohort study, accounting for 11.5% of all invited participants. According to the data per person and month (99,446 monthly submissions), AGI was reported for 5,508 person-months (5.5 per 100 person-months). Severe AGI was reported in 819 person-months (0.8 per 100 person-months). Our study estimates that 2–4% of AGI in Norway is attributable to drinking tap water.ConclusionsThis is the largest cohort study in Norway estimating the burden of self-reported gastrointestinal infections linked to the amount of tap water drunk in Norway. The data indicate that waterborne AGI is not currently a burden in Norway, but the findings need to be used with caution. The importance of continued efforts and investments in the maintenance of drinking water supplies in Norway to address the low burden of sporadic waterborne cases and to prevent future outbreaks needs to be emphasised.

Association between Combined Sewer Overflow Events and Gastrointestinal Illness in Massachusetts Municipalities with and without River-Sourced Drinking Water, 2014-2019.

Combined sewer overflow (CSO) events release untreated wastewater into surface waterbodies during heavy precipitation and snowmelt. Combined sewer systems serve people in the United States, primarily in urban and suburban municipalities in the Midwest and Northeast. Predicted increases in heavy precipitation events driven by climate change underscore the importance of quantifying potential health risks associated with CSO events. The aims of this study were to a) estimate the association between CSO events (2014-2019) and emergency department (ED) visits for acute gastrointestinal illness (AGI) among Massachusetts municipalities that border a CSO-impacted river, and b) determine whether associations differ by municipal drinking water source. A case time-series design was used to estimate the association between daily cumulative upstream CSO discharge and ED visits for AGI over lag periods of 4, 7, and 14 days, adjusting for temporal trends, temperature, and precipitation. Associations between CSO events and AGI were also compared by municipal drinking water source (CSO-impacted river vs. other sources). Extreme upstream CSO discharge events (th percentile by cumulative volume) were associated with a cumulative risk ratio (CRR) of AGI of 1.22 [95% confidence interval (CI): 1.05, 1.42] over the next 4 days for all municipalities, and the association was robust after adjusting for precipitation [1.17 (95% CI: 0.98, 1.39)], although the CI includes the null. In municipalities with CSO-impacted drinking water sources, the adjusted association was somewhat less pronounced following 95th percentile CSO events [ 1.05 (95% CI: 0.82, 1.33)]. The adjusted CRR of AGI was 1.62 in all municipalities following 99th percentile CSO events (95% CI: 1.04, 2.51) and not statistically different when stratified by drinking water source. In municipalities bordering a CSO-impacted river in Massachusetts, extreme CSO events are associated with higher risk of AGI within 4 days. The largest CSO events are associated with increased risk of AGI regardless of drinking water source. https://doi.org/10.1289/EHP14213.

Community intervention trial for estimating risk of acute gastrointestinal illness from groundwater-supplied non-disinfected drinking water.

By community intervention in 14 non-disinfecting municipal water systems, we quantified sporadic acute gastrointestinal illness (AGI) attributable to groundwater. Ultraviolet (UV) disinfection was installed on all supply wells of intervention communities. In control communities, residents continued to drink non-disinfected groundwater. Intervention and control communities switched treatments by moving UV disinfection units at the study midpoint (crossover design). Study participants (n = 1,659) completed weekly health diaries during four 12-week surveillance periods. Water supply wells were analyzed monthly for enteric pathogenic viruses. Using the crossover design, groundwater-borne AGI was not observed. However, virus types and quantity in supply wells changed through the study, suggesting that exposure was not constant. Alternatively, we compared AGI incidence between intervention and control communities within the same surveillance period. During Period 1, norovirus contaminated wells and AGI attributable risk from well water was 19% (95% CI, -4%, 36%) for children <5 years and 15% (95% CI, -9%, 33%) for adults. During Period 3, echovirus 11 contaminated wells and UV disinfection slightly reduced AGI in adults. Estimates of AGI attributable risks from drinking non-disinfected groundwater were highly variable, but appeared greatest during times when supply wells were contaminated with specific AGI-etiologic viruses.

Assessing the risk of acute gastrointestinal illness (AGI) acquired through recreational exposure to combined sewer overflow-impacted waters in Philadelphia: A quantitative microbial risk assessment

Combined sewer overflows (CSOs) are known contributors of human fecal pollution in urban waterways. Exposure to these waterways occurs during recreational activities, including swimming, wading, and fishing. This study used quantitative microbial risk assessment (QMRA) to estimate the risk of acute gastrointestinal illness (AGI) due to recreation during CSO-impacted (< 24 h after a CSO) and non-impacted (> 24 h after a CSO) conditions. Water samples (n = 69) were collected from two creeks and one river in Philadelphia from June–August 2017–2019. HF183 concentrations were measured to estimate concentrations of five reference pathogens: Cryptosporidium, Giardia, norovirus, E. coli O157:H7, and Salmonella. Observational data on the types and frequency of recreational exposures were also collected. Results found that recreating < 24 h after a CSO increased AGI risk by 39–75%, compared to recreating > 24 h after a CSO. However, estimated health risks were still high for some exposure scenarios that occurred > 24 h after a CSO. Crudes estimates determined that recreational activities along known CSO-impacted sites may account for 1–8% of all cases of salmonellosis, cryptosporidiosis, and giardiasis in the city of Philadelphia. Findings support risk reduction strategies that aim to reduce the frequency of CSOs in urban settings and may help target risk mitigation strategies.

Microbial risk assessment and mitigation options for wastewater treatment in Arctic Canada

Populations in Arctic Canada are strongly connected to, and draw sustenance from, the physical environment. Recreation and food harvesting locations, however, may be impacted by the basic wastewater treatment and disposal processes used in the region. Within these mixed socio-ecological systems, people may unknowingly be exposed to wastewater pathogens, either by direct contact or indirectly through activities resulting in exposure to contaminated locally harvested food. The objectives of this research are to estimate microbial health risks attributable to wastewater effluent exposure in Arctic Canada and evaluate potential mitigation options. A participatory quantitative microbial risk assessment (QMRA) approach was used. Specifically, community knowledge and information describing human activity patterns in wastewater-impacted environments was used with microbial water quality data to model a range of exposure scenarios and risk mitigation options. In several exposure scenario results, estimated individual annual risk of acute gastrointestinal illness exceeds a proposed tolerable target of 10−3. These scenarios include shore recreation and consumption of shellfish harvested near primary mechanical treatment plants at low tide, as well as travel in wetland portions of passive treatment sites during spring freshet. These results suggest that wastewater effluent exposures may be contributing to gastrointestinal illness in some Arctic communities. Mitigation strategies, including improved treatment and interventions aimed at deterring access to disposal areas reduce risk estimates across scenarios to varying degrees. Overall, well-designed passive systems appear to be the most effective wastewater treatment option for Arctic Canada in terms of limiting and managing associated microbial health risks. This research demonstrates a novel application of QMRA and provides science-based evidence to support public health, water, and sanitation decisions and investment in Arctic regions.

Promoting Inuit health through a participatory whiteboard video.

The Inuit community of Rigolet experiences greater rates of self-reported acute gastrointestinal illness (AGI) compared to southern Canada. A whiteboard video tool was collaboratively developed by Rigolet youth, community members, the research team and key regional stakeholders to share public health recommendations for reducing the risk of AGI. The video debuted in Rigolet at a community event in August 2016 and was later provided online for community members and local and regional health departments. Interviews and focus group discussions were used to evaluate the ability of the video to communicate public health information to community members in Rigolet. Community and government viewers reported that the whiteboard video was novel and engaging. Evaluation participants believed the video was suitable for promoting Inuit health because of the use of locally relevant visuals and narrative, which reflect Inuit art and storytelling traditions. Furthermore, participants indicated that the video co-development process was critical to ensuring community relevance of the video. Short-term outcome results suggest the video can reinforce health knowledge and potentially encourage behavioural change. The results suggest this whiteboard video was an effective tool to share information and could increase intention to change behaviours to reduce the risk of AGI in Rigolet. While tools like the whiteboard video are gaining popularity, the participatory approach was used to develop the video, and its use in an Inuit context illustrates its innovation and novelty. This tool may be a useful health promotion tool among Indigenous communities in Canada.

Quantitative Microbial Risk Assessment for Spray Irrigation of Dairy Manure Based on an Empirical Fate and Transport Model.

Background:Spray irrigation for land-applying livestock manure is increasing in the United States as farms become larger and economies of scale make manure irrigation affordable. Human health risks from exposure to zoonotic pathogens aerosolized during manure irrigation are not well understood.Objectives:We aimed to a) estimate human health risks due to aerosolized zoonotic pathogens downwind of spray-irrigated dairy manure; and b) determine which factors (e.g., distance, weather conditions) have the greatest influence on risk estimates.Methods:We sampled downwind air concentrations of manure-borne fecal indicators and zoonotic pathogens during 21 full-scale dairy manure irrigation events at three farms. We fit these data to hierarchical empirical models and used model outputs in a quantitative microbial risk assessment (QMRA) to estimate risk [probability of acute gastrointestinal illness (AGI)] for individuals exposed to spray-irrigated dairy manure containing Campylobacter jejuni, enterohemorrhagic Escherichia coli (EHEC), or Salmonella spp.Results:Median risk estimates from Monte Carlo simulations ranged from to and decreased with distance from the source. Risk estimates for Salmonella or EHEC-related AGI were most sensitive to the assumed level of pathogen prevalence in dairy manure, while risk estimates for C. jejuni were not sensitive to any single variable. Airborne microbe concentrations were negatively associated with distance and positively associated with wind speed, both of which were retained in models as a significant predictor more often than relative humidity, solar irradiation, or temperature.Conclusions:Our model-based estimates suggest that reducing pathogen prevalence and concentration in source manure would reduce the risk of AGI from exposure to manure irrigation, and that increasing the distance from irrigated manure (i.e., setbacks) and limiting irrigation to times of low wind speed may also reduce risk. https://doi.org/10.1289/EHP283

Gastrointestinal illness linked to incidents in drinking water distribution networks in Sweden

During recent years, knowledge gaps on drinking water-related gastrointestinal illness have been identified, especially for non-epidemic cases. Pathogen contamination of drinking water during distribution has been suggested to contribute to these cases, but the risk factors are not yet fully understood.During 2014–2015, we conducted an epidemiological study in five municipalities in Sweden, to assess whether incidents in the drinking water distribution system influence the risk of gastrointestinal illness. Telephone interviews were conducted in the affected areas and in reference areas 7–14 days after a reported incident. Symptoms of gastrointestinal illness occurring during the period were documented for each household member.The results showed a significantly elevated risk of vomiting and acute gastrointestinal illness (AGI) in the affected areas, compared to the reference areas (ORvom. = 2.0, 95% CI: 1.2–3.3; ORAGI = 1.9, 95% CI: 1.2–3.0). Certain conditions, or risk factors, during the incidents, such as sewage and drinking water pipelines at the same level in the trench, were associated with an elevated risk of AGI and vomiting. Safety measures taken during repair work, like flushing, were also associated with an elevated risk of AGI and vomiting.These results show that incidents in the drinking water distribution network contribute to endemic gastrointestinal illness, especially AGI and vomiting, and that external pathogen contamination of the drinking water is a likely cause of these cases of gastrointestinal illness. The results also indicate that safety measures used today may not be sufficient for eliminating the risk of gastrointestinal illness.

Review: Epidemiological evidence of groundwater contribution to global enteric disease, 1948–2015

Globally, approximately 2.2 billion people rely on groundwater for daily consumption. It is widely accepted that groundwater is more pristine than surface water but while this assumption is frequently the case, groundwater is not ubiquitously free of contaminants; accordingly, this presumption can result in an unfounded and potentially hazardous sense of security among owners, operators and users. The current paper presents a review of published literature providing epidemiological evidence of the contribution of groundwater to global human enteric infection. An emphasis is placed on enteric pathogens transmitted via the faecal-oral route, and specifically those associated with acute gastrointestinal illness (AGI). The review identified 649 published groundwater outbreaks globally between 1948 and 2013 and several epidemiological studies that show there is an increased risk of AGI associated with the consumption of untreated groundwater. The review identified that the following five pathogens were responsible for most outbreaks: norovirus, Campylobacter, Shigella, Hepatitis A and Giardia. Crudely, the authors estimate that between 35.2 and 59.4 million cases of AGI per year globally could be attributable to the consumption of groundwater. Although groundwater is frequently presumed to be a microbiologically safe source of water for consumption, this review demonstrates that consumers served by an untreated groundwater supply remain at risk to enteric disease. The authors conclude that collaboration between microbiologists, hydrogeologists and epidemiologists is needed to better understand pathogen occurrence, persistence, detection and transport in groundwater as well as build stronger epidemiological evidence documenting the true magnitude of disease associated with groundwater globally.

Perceptions of Risk and Optimistic Bias for Acute Gastrointestinal Illness: A Population Survey

Optimistic bias refers to the tendency of individuals to believe that they are less likely to experience negative events compared with other people. Individuals who perceive their risk of an adverse health event to be low may not be as receptive to informational messages aimed at disease prevention. Our objective was to estimate the magnitude of optimistic bias for acute gastrointestinal illness, and to describe demographic associations with, and reasons for, individuals' perception of personal risk. Data were obtained by a retrospective, cross-sectional telephone survey of 2057 randomly selected English-speaking residents of Ontario, Canada conducted between May 2005 and April 2006. Data were collected on the occurrence of acute gastrointestinal illness during the 28 days prior to the survey, demographics, respondents' perception of their personal risk of acute gastrointestinal illness compared with the average person, and the reasons for this perception. Associations with perception of illness were evaluated using ordinal logistic regression and reasons for perception of risk were explored qualitatively. Optimistic bias was present among all respondents, but was not statistically significant within the group that had experienced acute gastrointestinal illness in the previous 28 days. Rural residency and not having experienced acute gastrointestinal illness in the previous 28 days were associated with a lower perception of risk compared with the average person. Proportionally fewer individuals who had not completed secondary education saw themselves as at less than average risk. The most common reason given for the perception of lower risk was that the respondent was healthier than the average person, although personal lifestyle choices also were provided as reasons. The presence of optimistic bias may negatively impact compliance with public health initiatives to reduce acute gastrointestinal illness. Therefore, recognizing the demographic characteristics associated with a perception of lower risk and understanding the reasons for this perception may help with targeting effective preventive messaging.

The association between farming activities, precipitation, and the risk of acute gastrointestinal illness in rural municipalities of Quebec, Canada: a cross-sectional study

BackgroundIncreasing livestock density and animal manure spreading, along with climate factors such as heavy rainfall, may increase the risk of acute gastrointestinal illness (AGI). In this study we evaluated the association between farming activities, precipitation and AGI.MethodsA cross-sectional telephone survey of randomly selected residents (n = 7006) of 54 rural municipalities in Quebec, Canada, was conducted between April 2007 and April 2008. AGI symptoms and several risk factors were investigated using a phone questionnaire. We calculated the monthly prevalence of AGI, and used multivariate logistic regression, adjusting for several demographic and risk factors, to evaluate the associations between AGI and both intensive farming activities and cumulative weekly precipitation. Cumulative precipitation over each week, from the first to sixth week prior to the onset of AGI, was analyzed to account for both the delayed effect of precipitation on AGI, and the incubation period of causal pathogens. Cumulative precipitation was treated as a four-category variable: high (≥90th percentile), moderate (50th to <90th percentile), low (10th to <50th percentile), and very low (<10th percentile) precipitation.ResultsThe overall monthly prevalence of AGI was 5.6% (95% CI 5.0%-6.1%), peaking in winter and spring, and in children 0-4 years old. Living in a territory with intensive farming was negatively associated with AGI: adjusted odds ratio (OR) = 0.70 (95% CI 0.51-0.96). Compared to low precipitation periods, high precipitation periods in the fall (September, October, November) increased the risk of AGI three weeks later (OR = 2.20; 95% CI 1.09-4.44) while very low precipitation periods in the summer (June, July, August) increased the risk of AGI four weeks later (OR = 2.19; 95% CI 1.02-4.71). Further analysis supports the role of water source on the risk of AGI.ConclusionsAGI poses a significant burden in Quebec rural municipalities with a peak in winter. Intensive farming activities were found to be negatively associated with AGI. However, high and very low precipitation levels were positively associated with the occurrence of AGI, especially during summer and fall. Thus, preventive public health actions during such climate events may be warranted.

Burden of Self-reported Acute Gastrointestinal Illness in Cuba

Acute gastrointestinal illness is an important public-health issue worldwide. Burden-of-illness studies have not previously been conducted in Cuba. The objective of the study was to determine the magnitude, distribution, and burden of self-reported acute gastrointestinal illness in Cuba. A retrospective, cross-sectional survey was conducted in three sentinel sites during June-July 2005 (rainy season) and during November 2005-January 2006 (dry season). Households were randomly selected from a list maintained by the medical offices in each site. One individual per household was selected to complete a questionnaire in a face-to-face interview. The case definition was three or more bouts of loose stools in a 24-hour period within the last 30 days. In total, 97.3% of 6,576 interviews were completed. The overall prevalence of acute gastrointestinal illness was 10.6%. The risk of acute gastrointestinal illness was higher during the rainy season (odds ratio [OR]=3.85, 95% confidence interval [CI] 3.18-4.66) in children (OR=3.12, 95% CI 2.24-4.36) and teens (OR=2.27, 95% CI 1.51-3.41) compared to people aged 25-54 years, in males (OR=1.24, 95% CI 1.04-1.47), and in the municipality of Santiago de Cuba (OR=1.33, 95% CI 1.11-1.61). Of 680 cases, 17.1-38.1% visited a physician, depending on sentinel site. Of the cases who visited a physician, 33.3-53.9% were requested to submit a stool sample, and of those, 72.7-100.0% complied. Of the cases who sought medical care, 16.7-61.5% and 0-31.6% were treated with antidiarrhoeals and antibiotics respectively. Acute gastrointestinal illness represented a substantial burden of health compared to developed countries. Targeting the identified risk factors when allocating resources for education, food safety, and infrastructure might lower the morbidity associated with acute gastrointestinal illness.

Demographic determinants of acute gastrointestinal illness in Canada: a population study

BackgroundGastrointestinal illness is an important global public health issue, even in developed countries, where the morbidity and economic impact are significant. Our objective was to evaluate the demographic determinants of acute gastrointestinal illness in Canadians.MethodsWe used data from two population-based studies conducted in select communities between 2001 and 2003. Together, the studies comprised 8,108 randomly selected respondents; proxies were used for all respondents under 12 years and for respondents under 19 years at the discretion of the parent or guardian. Using univariate and multivariate logistic regression, we evaluated the following demographic determinants: age, gender, cultural group, and urban/rural status of the respondent, highest education level of the respondent or proxy, number of people in the household, and total annual household income. Two-way interaction terms were included in the multivariate analyses. The final multivariate model included income, age, gender, and the interaction between income and gender.ResultsAfter adjusting for income, gender, and their interaction, children under 10 years had the highest risk of acute gastrointestinal illness, followed by young adults aged 20 to 24 years. For males, the risk of acute gastrointestinal illness was similar across all income levels, but for females the risk was much higher in the lowest income category. Specifically, in those with total annual household incomes of less than $20,000, the odds of acute gastrointestinal illness were 2.46 times higher in females than in males.ConclusionUnderstanding the demographic determinants of acute gastrointestinal illness is essential in order to identify vulnerable groups to which intervention and prevention efforts can be targeted.

ACUTE GASTROINTESTINAL ILLNESS AND CHILD CARE ARRANGEMENTS

This study uses data from the 1981 National Health Interview and the 1981 Child Health Supplement to assess the extent to which family day care homes and child care centers pose a risk of acute gastrointestinal illness among preschool children. The study uses a nationally representative sample of children 0-5 years of age (n = 4,845). Acute gastrointestinal illness was identified from parental reports of acute illness in a 2-week period. Information on type and duration of child care, as well as a variety of sociodemographic and environmental factors (e.g., crowding, seasonality), were obtained. The authors hypothesize that risk of acute gastrointestinal illness would vary by group size. Center attendees were thought to have the greatest exposure to infectious agents, followed by children in day care homes, and lastly by those receiving care in their own homes. Risk models were estimated separately for children less than 3 years of age and for children aged 3-5 years. Our results show that an elevated risk of acute gastrointestinal illness associated with child care is confined to children less than 3 years of age who regularly attend centers/nursery schools (odds ratio = 3.49, 95% confidence interval 0.99-4.77), controlling for other confounding variables. For children aged 3-5 years, low socioeconomic status, poverty, and seasonality are stronger predictors of acute gastrointestinal illness than is center care. Family day care appears to be unrelated to the risk of illness for both age groups.

Infant formulas and gastrointestinal illness.

Infants under age one in a pediatric practice were followed prospectively, and the determinants of acute gastrointestinal illness were evaluated in case-control pairs, matched by birth month. The risk of acute gastrointestinal illness in infants receiving formula was six times greater than in infants receiving breast milk and 2.5 times greater than in infants receiving cow milk. In the second six months of life, infants on formula had 0.38 more gastrointestinal illness episodes per child than infants on cow milk. Episodes without rotavirus or bacterial agents accounted for most of the increased risk of formula. The increased risk could not be explained by iron fortification of the formulas, prescription of non-milk based formulas to high-risk infants, case ascertainment bias, control selection bias, or numerous control factors. Non-antibody anti-infection properties found in cow milk are one possible explanation for these findings.