Association between rainfall and pediatric emergency department visits for acute gastrointestinal illness

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

BACKGROUND

Combined sewer overflow (CSO) events release untreated wastewater into surface waterbodies during heavy precipitation and snowmelt. Combined sewer systems serve ∼ 40  million 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.

OBJECTIVES

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.

METHODS

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).

RESULTS

Extreme upstream CSO discharge events (> 95 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 [CRR = 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.

DISCUSSION

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.

Relationship between extreme precipitation and acute gastrointestinal illness in Toronto, Ontario, 2012-2022

Extreme precipitation events are occurring more intensely in Canada. This can contaminate water sources with enteric pathogens, potentially increasing the risk of acute gastrointestinal illness. This study aimed to investigate the relationship between extreme precipitation and emergency department (ED) visits for acute gastrointestinal illness in Toronto from 2012 to 2022. Distributed lag non-linear models were constructed on ED visit counts with a Quasi Poisson distribution. Extreme precipitation was modelled as a 21-day lag variable, with a linear relationship assumed at levels ≧95th percentile. Separate models were also conducted on season-specific data sets. Daily precipitation and gastrointestinal illness ED visits ranged between 0 to 126 mm, and 12 to 180 visits respectively. Overall, a 10-mm increase in precipitation >95th percentile had no significant relationship with the risk of ED visits. However, stratification by seasons revealed significant relationships during spring (lags 1-19, peak at lag 14 RR = 1.04; 95% CI: 1.03, 1.06); the overall cumulative effect across the 21-day lag was also significant (RR = 1.94; 95% CI: 1.47, 2.57). Extreme precipitation has a seasonal effect on gastrointestinal health outcomes in Toronto city, suggesting varying levels of enteric pathogen exposures through drinking water or other environmental pathway during different seasons.

The Built Environment and Pediatric Health

Buildings, parks, and roads are all elements of the "built environment," which can be described as the human-made structures that comprise the neighborhoods and communities where people live, work, learn, and recreate (https://www.epa.gov/smm/basic-information-about-built-environment). The design of communities where children and adolescents live, learn, and play has a profound impact on their health. Moreover, the policies and practices that determine community design and the built environment are a root cause of disparities in the social determinants of health that contribute to health inequity. An understanding of the links between the built environment and pediatric health will help to inform pediatricians' and other pediatric health professionals' care for patients and advocacy on their behalf. This technical report describes the range of pediatric physical and mental health conditions influenced by the built environment, as well as historical and persistent effects of the built environment on health disparities. The accompanying policy statement outlines community design solutions that can improve pediatric health and health equity, including opportunities for pediatricians and the health care sector to incorporate this knowledge in patient care, as well as to play a role in advancing a health-promoting built environment for all children and families.

Quantifying the land and population risk of sewage spills overland using a fine-scale, DEM-based GIS model

Accidental releases of untreated sewage into the environment, known as sewage spills, may cause adverse gastrointestinal stress to exposed populations, especially in young, elderly, or immune-compromised individuals. In addition to human pathogens, untreated sewage contains high levels of micropollutants, organic matter, nitrogen, and phosphorus, potentially resulting in aquatic ecosystem impacts such as algal blooms, depleted oxygen, and fish kills in spill-impacted waterways. Our Geographic Information System (GIS) model, Spill Footprint Exposure Risk (SFER) integrates fine-scale elevation data (1/3 arc-second) with flowpath tracing methods to estimate the expected overland pathways of sewage spills and the locations where they are likely to pool. The SFER model can be integrated with secondary measures tailored to the unique needs of decision-makers so they can assess spatially potential exposure risk. To illustrate avenues to assess risk, we developed risk measures for land and population health. The land risk of sewage spills is calculated for subwatershed regions by computing the proportion of the subwatershed's area that is affected by one modeled footprint. The population health risk is assessed by computing the estimated number of individuals who are within the modeled footprint using fine-scale (90 square meters) population estimates data from LandScan USA. In the results, with a focus on the Atlanta metropolitan region, potential strategies to combine these risk measures with the SFER model are outlined to identify specific areas for intervention.

Effects of High Temperature and Heavy Precipitation on Drinking Water Quality and Child Hand Contamination Levels in Rural Kenya

Climate change may impact human health through the influence of weather on environmental transmission of diarrhea. Previous studies have found that high temperatures and heavy precipitation are associated with increased diarrhea prevalence, but the underlying causal mechanisms have not been tested and validated. We linked measurements of Escherichia coli in source water (n = 1673), stored drinking water (n = 9692), and hand rinses from children <2 years old (n = 2634) with publicly available gridded temperature and precipitation data (at ≤0.2 degree spatial resolution and daily temporal resolution) by the GPS coordinates and date of sample collection. Measurements were collected over a 3-year period across a 2500 km² area in rural Kenya. In drinking water sources, high 7-day temperature was associated with a 0.16 increase in log₁₀ E. coli levels (p < 0.001, 95% CI: 0.07, 0.24), while heavy 7-day total precipitation was associated with a 0.29 increase in log₁₀ E. coli levels (p < 0.001, 95% CI: 0.13, 0.44). In household stored drinking water, heavy 7-day precipitation was associated with a 0.079 increase in log₁₀ E. coli levels (p = 0.042, 95% CI: 0.07, 0.24). Heavy precipitation did not increase E. coli levels among respondents who treated their water, suggesting that water treatment can mitigate effects on water quality. On child hands, high 7-day temperature was associated with a 0.39 decrease in log₁₀ E. coli levels (p < 0.001, 95% CI: -0.52, -0.27). Our findings provide insight on how climate change could impact environmental transmission of bacterial pathogens in Kenya. We suggest water treatment is especially important after heavy precipitation (particularly when preceded by dry periods) and high temperatures.

Child-focused climate change and health content in medical schools and pediatric residencies

Anthropogenic climate change-driven primarily by the combustion of fossil fuels that form greenhouse gases-has numerous consequences that impact health, including extreme weather events of accelerating frequency and intensity (e.g., wildfires, thunderstorms, droughts, and heat waves), mental health sequelae of displacement from these events, and the increase in aeroallergens and other pollutants. Children are especially vulnerable to climate-related exposures given that they are still developing, encounter higher exposures compared to adults, and are at risk of losing many healthy future years of life. In order to better meet the needs of generations of children born into a world affected by climate change, medical trainees must develop their knowledge of the relationships between climate change and children's health-with a focus on applying that information in clinical practice. This review provides an overview of salient climate change and children's health topics that medical school and pediatric residency training curricula should cover. In addition, it highlights the strengths and limitations of existing medical school and residency climate change and pediatric health curricula. IMPACT: Provides insight into the current climate change and pediatric health curricular opportunities for medical trainees in North America at both the medical school and residency levels. Condenses climate change and pediatric health material relevant to trainees to help readers optimize curricula at their institutions.

Sanitary sewage overflows, boil water advisories, and emergency room and urgent care visits for gastrointestinal illness: a case-crossover study in South Carolina, USA, 2013-2017

BACKGROUND

Sanitary sewage overflows (SSOs) release raw sewage, which may contaminate the drinking water supply. Boil water advisories (BWAs) are issued during low or negative pressure events, alerting customers to potential contamination in the drinking water distribution system.

OBJECTIVE

We evaluated the associations between SSOs and BWAs and diagnoses of gastrointestinal (GI) illness in Columbia, South Carolina, and neighboring communities, 2013-2017.

METHODS

A symmetric bi-directional case-crossover study design was used to assess the role of SSOs and BWAs on Emergency Room and Urgent Care visits with a primary diagnosis of GI illness. Cases were considered exposed if an SSO or BWA occurred 0-4 days, 5-9 days, or 10-14 days prior to the diagnosis, within the same residential zip code. Effect modification was explored via stratification on participant-level factors (e.g., sex, race, age) and season (January-March versus April-December).

RESULTS

There were 830 SSOs, 423 BWAs, and 25,969 cases of GI illness. Highest numbers of SSOs, BWAs and GI cases were observed in a zip code where >80% of residents identified as Black or African-American. SSOs were associated with a 13% increase in the odds of a diagnosis for GI illness during the 0-4 day hazard period, compared to control periods (Odds Ratio: 1.13, 95% Confidence Interval: 1.09, 1.18), while no associations were observed during the other hazard periods. BWAs were not associated with increased or decreased odds of GI illness during all three hazard periods. However, in stratified analyses BWAs issued between January-March were associated with higher odds of GI illness, compared to advisories issued between April-December, in all three hazard periods.

SIGNIFICANCE

SSOs (all months) and BWAs (January-March) were associated with increased odds of a diagnosis of GI illness. Future research should examine sewage contamination of the drinking water distribution system, and mechanisms of sewage intrusion from SSOs.

IMPACT

Sewage contains pathogens, which cause gastrointestinal (GI) illness. In Columbia, South Carolina, USA, between 2013-2017, there were 830 sanitary sewage overflows (SSOs). There were also 423 boil water advisories, which were issued during negative pressure events. Using case-crossover design, SSOs (all months) and boil water advisories (January-March) were associated with increased odds of Emergency Room and Urgent Care diagnoses of GI illness, potentially due to contamination of the drinking water distribution system. Lastly, we identified a community where >80% of residents identified as Black or African-American, which experienced a disproportionate burden of sewage exposure, compared to the rest of Columbia.

Exposure to industrial hog operations and gastrointestinal illness in North Carolina, USA

With 9 million hogs, North Carolina (NC) is the second leading hog producer in the United States. Most hogs are housed at concentrated animal feeding operations (CAFOs), where millions of tons of hog waste can pollute air and water with fecal pathogens that can cause diarrhea, vomiting, and/or nausea (known as acute gastrointestinal illness (AGI)). We used NC's ZIP code-level emergency department (ED) data to calculate rates of AGI ED visits (2016-2019) and swine permit data to estimate hog exposure. Case exposure was estimated as the inverse distances from each hog CAFO to census block centroids, weighting with Gaussian decay and by manure amount per CAFO, then aggregated to ZIP code using population weights. We compared ZIP codes in the upper quartile of hog exposure ("high hog exposed") to those without hog exposure. Using inverse probability of treatment weighting, we created a control with similar demographics to the high hog exposed population and calculated rate ratios using quasi-Poisson models. We examined effect measure modification of rurality and race using adjusted models. In high hog exposed areas compared to areas without hog exposure, we observed a 11% increase (95% CI: 1.06, 1.17) in AGI rate and 21% increase specifically in rural areas (95% CI: 0.98, 1.43). When restricted to rural areas, we found an increased AGI rate among American Indian (RR = 4.29, 95% CI: 3.69, 4.88) and Black (RR = 1.45, 95% CI: 0.98, 1.91) residents. The association was stronger during the week after heavy rain (RR = 1.41, 95% CI: 1.19, 1.62) and in areas with both poultry and swine CAFOs (RR = 1.52, 95% CI: 1.48, 1.57). Residing near CAFOs may increase rates of AGI ED visits. Hog CAFOs are disproportionally built near rural Black and American Indian communities in NC and are associated with increased AGI most strongly in these populations.

Epidemiologic Features of Acute Pediatric Diarrhea in Managua, Nicaragua, from 2011 to 2019

Diarrhea remains a leading cause of death in children in developing countries, including Nicaragua, but little is known about patterns of diarrhea occurrence in Central America over long periods of time. The purpose of this study was to determine the incidence, risk factors, long-term trends, and seasonality of diarrhea in children age 2 to 14 years in Managua, Nicaragua. From 2011 to 2019, we examined episodes of diarrhea among 6,485 children who participated in a prospective cohort study and presented for care in a primary care facility. We performed a longitudinal analysis considering time-varying variables and the intra-subject correlation of outcomes. In addition, we analyzed the weekly incidence of diarrhea, applying seasonal trend decomposition to extract secular and seasonal patterns. The overall incidence rate of diarrhea was 133.4 episodes per 1,000 person-years (95% CI, 128.3–138.7). We observed a slight increase in the incidence of diarrhea from 2011 to 2019. Younger age was the strongest predictor of the risk of diarrhea, and incidence increased with every additional hour without running water in the household per day. Diarrhea incidence in Managua was seasonal, with high peaks each year between May and July. Despite reductions in childhood mortality since 1990 in Nicaragua, diarrheal morbidity remains a major problem in Managua.

Combined Sewer Overflows and Gastrointestinal Illness in Atlanta, 2002-2013: Evaluating the Impact of Infrastructure Improvements

BACKGROUND

Combined sewer overflows (CSOs) discharge untreated sewage into surface and recreational water, often following heavy precipitation. Given projected increases in frequency and intensity of precipitation due to climate change, it is important to understand the health impacts of CSOs and mediating effects of sewerage systems.

OBJECTIVES

In this study we estimate associations of CSO events and emergency department (ED) visits for gastrointestinal (GI) illness among City of Atlanta, Georgia, residents and explore how these associations vary with sewerage improvements.

METHODS

We estimate associations using Poisson generalized linear models, controlling for time trends. We categorized CSOs by overflow volume and assessed effects of CSO events prior to ED visits with 1-, 2- and 3-wk lags. Similarly, we evaluated effects of weekly cumulative precipitation greater than the 90th percentile at the same lags. We also evaluated effect modification by ZIP Code Tabulation Area (ZCTA)-level poverty and infrastructure improvement period using interaction terms.

RESULTS

Occurrence of a large volume CSO in the previous week was associated with a 9% increase in daily ED visits for GI illness. We identified significant interaction by ZCTA-level poverty, with stronger CSO-GI illness associations in low than high poverty areas. Among areas with low poverty, we observed associations at 1-wk and longer lags, following both large and lower volume CSO events. We did not observe significant interaction by infrastructure improvement period for CSO- nor precipitation-GI illness associations; however, the number of CSO events decreased from 2.31 per week before improvements to 0.49 after improvements.

DISCUSSION

Our findings suggest that CSOs contribute to acute GI illness burden in Atlanta and that the magnitude of this risk may be higher among populations living in areas of low poverty. We did not find a protective effect of sewerage system improvements. Nonetheless, observed reductions in CSO frequency may lower the absolute burden of GI illness attributable to these events. https://doi.org/10.1289/EHP10399.

Attachment, re-mobilization, and inactivation of bacteriophage MS2 during bank filtration following simulation of a high virus load and an extreme rain event

Viruses, including human pathogenic viruses, can persist in water. For producing drinking water from surface water via bank filtration, natural attenuation capacities and the fate of viruses during the passage of aquatic sediments are of particular interest. Moreover, the increasing frequency of extreme hydrological events necessitate re-evaluation of the sustainability and efficacy of processes removing viruses. For this purpose, we performed bank sediment filtration experiments using a mesocosm in a technical-scale experimental facility that simulates a field situation under more tightly controlled conditions. We used the bacteriophage MS2 as a surrogate for enteric viruses to study the transport of different viral loads through the bank sediment. Additionally, we simulated a heavy rain event to investigate the re-mobilization of initially attached virus particles. We quantified the abundance of infectious MS2 phages by plaque assay and the total number of MS2 particles by qPCR. Also, we differentiated pore water concentrations by depths of the sediment column and investigated attachment to the sediment matrix at the end of the individual experimental phases. Bank filtration over a vertical distance of 80 cm through sandy sediment revealed a virus removal efficiency of 0.8 log₁₀ for total MS2 particles and 1.7 log₁₀ for infectious MS2 particles, with an initial phage concentration of 1.84 × 10⁸ gene copies mL^-1. A low load of infectious MS2 (1.9 × 10⁶ plaque forming units mL^-1) resulted in a greater removal efficiency (3.0 log₁₀). The proportion of infectious MS2 phages of the total MS2 particle mass steadily decreased over time, i.e., in the course of individual breakthrough curves and with sediment depth. The simulated pulse of rainwater caused a front of low ionic strength water which resulted in pronounced phage remobilization. The high proportion of infectious MS2 among the detached phages indicated that attachment to the sediment matrix may substantially conserve virus infectivity. Therefore, the re-mobilization of previously attached viruses owing to hydrological extremes should be considered in water quality assessment and monitoring schemes.

Hurricane flooding and acute gastrointestinal illness in North Carolina

Hurricanes often flood homes and industries, spreading pathogens. Contact with pathogen-contaminated water can result in diarrhea, vomiting, and/or nausea, known collectively as acute gastrointestinal illness (AGI). Hurricanes Matthew and Florence caused record-breaking flooding in North Carolina (NC) in October 2016 and September 2018, respectively. To examine the relationship between hurricane flooding and AGI in NC, we first calculated the percent of each ZIP code flooded after Hurricanes Matthew and Florence. Rates of all-cause AGI emergency department (ED) visits were calculated from NC's ED surveillance system data. Using controlled interrupted time series, we compared AGI ED visit rates during the three weeks after each hurricane in ZIP codes with a third or more of their area flooded to the predicted rates had these hurricanes not occurred, based on AGI 2016-2019 ED trends, and controlling for AGI ED visit rates in unflooded areas. We examined alternative case definitions (bacterial AGI) and effect measure modification by race and age. We observed an 11% increase (rate ratio (RR): 1.11, 95% CI: 1.00, 1.23) in AGI ED visit rates after Hurricanes Matthew and Florence. This effect was particularly strong among American Indian patients and patients aged 65 years and older after Florence and elevated among Black patients for both hurricanes. Florence's effect was more consistent than Matthew's effect, possibly because little rain preceded Florence and heavy rain preceded Matthew. When restricted to bacterial AGI, we found an 85% (RR: 1.85, 95% CI: 1.37, 2.34) increase in AGI ED visit rate after Florence, but no increase after Matthew. Hurricane flooding is associated with an increase in AGI ED visit rate, although the strength of effect may depend on total storm rainfall or antecedent rainfall. American Indians and Black people-historically pushed to less desirable, flood-prone land-may be at higher risk for AGI after storms.

The effectiveness of syndromic surveillance for the early detection of waterborne outbreaks: a systematic review

Background

Waterborne outbreaks are still a risk in high-income countries, and their early detection is crucial to limit their societal consequences. Although syndromic surveillance is widely used for the purpose of detecting outbreaks days earlier than traditional surveillance systems, evidence of the effectiveness of such systems is lacking. Thus, our objective was to conduct a systematic review of the effectiveness of syndromic surveillance to detect waterborne outbreaks.

Method

We searched the Cochrane Library, Medline/PubMed, EMBASE, Scopus, and Web of Science for relevant published articles using a combination of the keywords ‘drinking water’, ‘surveillance’, and ‘waterborne disease’ for the period of 1990 to 2018. The references lists of the identified articles for full-text record assessment were screened, and searches in Google Scholar using the same key words were conducted. We assessed the risk of bias in the included articles using the ROBINS-I tool and PRECEPT for the cumulative body of evidence.

Results

From the 1959 articles identified, we reviewed 52 articles, of which 18 met the eligibility criteria. Twelve were descriptive/analytical studies, whereas six were simulation studies. There is no clear evidence for syndromic surveillance in terms of the ability to detect waterborne outbreaks (low sensitivity and high specificity). However, one simulation study implied that multiple sources of signals combined with spatial information may increase the timeliness in detecting a waterborne outbreak and reduce false alarms.

Conclusion

This review demonstrates that there is no conclusive evidence on the effectiveness of syndromic surveillance for the detection of waterborne outbreaks, thus suggesting the need to focus on primary prevention measures to reduce the risk of waterborne outbreaks. Future studies should investigate methods for combining health and environmental data with an assessment of needed financial and human resources for implementing such surveillance systems. In addition, a more critical thematic narrative synthesis on the most promising sources of data, and an assessment of the basis for arguments that joint analysis of different data or dimensions of data (e.g. spatial and temporal) might perform better, should be carried out.

Trial registration

PROSPERO: International prospective register of systematic reviews. 2019. CRD42019122332.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06387-y.

A 21-year retrospective analysis of environmental impacts on paediatric acute gastroenteritis in an affluent setting

BACKGROUND

Extreme weather events happen more frequently along with global warming and they constitute a challenge for public health preparedness. For example, many investigations showed heavy rainfall was associated with an increased risk of acute gastroenteritis. In this study, we examined the associations between different meteorological factors and paediatric acute gastroenteritis in an affluent setting in China controlling for pollutant effects.

METHODS

Aggregated total weekly number of intestinal infection-related hospital admissions, and meteorological and air pollution data during 1998-2018 in Hong Kong were collected and analysed by a combination of quasi-Poisson generalized additive model and distributed lag nonlinear model. Study population was restricted to children under 5 years of age at the time of admission.

RESULTS

While heavy rainfall did not exhibit a statistically significant association with the risk of paediatric admission due to intestinal infections, low temperature and humidity extremes (both relative humidity and vapour pressure) did. Compared with the temperature at which the lowest risk was detected (i.e. 22.5 °C), the risk was 6.4% higher (95% confidence interval: 0.0% to 13.0% at 15.1 °C (i.e. the 5th percentile)). We also found the risk of paediatric admission was statistically significantly associated with an increase in the number of extreme cold days in a week over the study period.

CONCLUSION

Cold condition may have greater impact on disease transmission through increased stability and infectivity of enteric viruses in affluent settings like Hong Kong and thus resulted in an increased risk for paediatric acute gastroenteritis. On the contrary, an insignificant impact from heavy rainfall and high temperature may indicate a minor effect on disease transmission through bacterial growth in contaminated food and water. With the identified impacts of weather factors, extreme weather events are likely to distort the prevalence and seasonal pattern of diarrhoeal diseases in the future.

Climate Change and the Practice of Medicine: Essentials for Resident Education

Despite calls for including content on climate change and its effect on health in curricula across the spectrum of medical education, no widely used resource exists to guide residency training programs in this effort. This lack of resources poses challenges for training program leaders seeking to incorporate evidence-based climate and health content into their curricula. Climate change increases risks of heat-related illness, infections, asthma, mental health disorders, poor perinatal outcomes, adverse experiences from trauma and displacement, and other harms. More numerous and increasingly dangerous natural disasters caused by climate change impair delivery of care by disrupting supply chains and compromising power supplies. Graduating trainees face a knowledge gap in understanding, managing, and mitigating these many-faceted consequences of climate change, which-expected to intensify in coming decades-will influence both the health of their patients and the health care they deliver. In this article, the authors propose a framework of climate change and health educational content for residents, including how climate change (1) harms health, (2) necessitates adaptation in clinical practice, and (3) undermines health care delivery. The authors propose not only learning objectives linked to the Accreditation Council for Graduate Medical Education core competencies for resident education but also learning formats and assessment strategies in each content area. They also present opportunities for implementation of climate and health education in residency training programs. Including this content in residency education will better prepare doctors to deliver anticipatory guidance to at-risk patients, manage those experiencing climate-related health effects, and reduce care disruptions during climate-driven extreme weather events.

Effects of weather, air pollution and Oktoberfest on ambulance-transported emergency department admissions in Munich, Germany

BACKGROUND

Climate change and increasing risks of extreme weather events affect human health and lead to changes in the emergency department (ED) admissions and the emergency medical services (EMS) operations. For a better allocation of resources in the healthcare system, it is essential to predict ED numbers based on environmental variables. This publication aims to quantify weather, air pollution and calendar-related effects on daily ED admissions.

METHODS

Analyses were based on 575,725 admissions from the web-based IVENA system recording all patients in the greater Munich area with pre-hospital emergency care in ambulance operations during 2014-2018. Linear models were used to identify statistically significant associations between daily ED admissions and calendar, meteorological and pollution factors, allowing for lag effects of one to three days. Separate analyses were performed for seasons, with additional subset analyses by sex, age and surgical versus internal department.

RESULTS

ED admissions were exceptionally high during the three-week Oktoberfest, particularly for males and on the weekends, as well as during the New Year holiday. Admissions significantly increased during the years of study, decreased in spring and summer holidays, and were lower on Sundays while higher on Mondays. In the warmer seasons, admissions were significantly associated with higher temperature, adjusting for the effects of sunshine and humidity in all age groups except for the elderly. Adverse weather conditions in non-summer seasons were either linked to increasing ED admissions (from storms, gust) or decreasing them from rain. Mostly, but not exclusively, in winter, increasing ED admissions were associated with colder minimum temperatures as well as with higher NO and PM₁₀ concentrations.

CONCLUSIONS

In addition to standard calendar-related factors, incorporating seasonal weather, air pollutant and interactions with patient demographics into resource planning models can improve the daily allocation of resources and staff of EMS operations at hospital and city levels.

Effects of heavy rainfall on waterborne disease hospitalizations among young children in wet and dry areas of New Zealand

Heavy rainfall is associated with increased risk of waterborne disease. However, it is not known whether the risk increment differs between wet and dry regions. We examined this question in New Zealand, which has a wide geographical variation of annual rainfall totals (10^th-90^th percentile difference ≥3000 mm). We conducted a nested case-crossover study within a prospective child cohort (born in 2009-2010) for assessing transient health effects when modified by longitudinal exposures to rainfall. Short-term heavy rainfall effects on hospitalizations due to enteric bacterial and viral infectious causes at lag of 0-14 days were assessed using a Cox regression model adjusted for daily temperature, relative humidity and evapotranspiration. We derived quantiles of time-weighted long-term rainfall levels at the children's homes and these were added as an interaction term to the short-term effect model. Hospitalization risks were higher two days after heavy rainfall days (hazard ratio [95% confidence interval]: 1.73 [1.10-2.70]). The lowest-observable-adverse-effect-level was detected at the 94^th percentile of daily rainfall total. Hospital admissions 1-2 days after heavy rainfall increased most in locations with the lowest and highest long-term rainfall. An interaction of this kind between short-term weather and long-term climate has not been reported previously. It is relevant to climate change risk assessments given global projections of increasing intensity of precipitation, against a background of more severe, and possibly more frequent, droughts and flooding.

Rainfall and child weight in Uganda

We combine data from the 2006 and 2011 Uganda Demographic and Health Surveys (UDHS) with rainfall data and two waves of the Ugandan National Household Survey (UNHS) to study patterns in child weight, as measured by weight-for-height z scores (WHZ), among 3492 rural children below age 5 in Uganda. We focus on rainfall as a nutrition driver along agriculture and disease pathways. We find a positive and significant association between crop yield and WHZ, but the magnitude of this association diminishes as we control for covariates, especially the use of productivity-enhancing agricultural inputs. We find diarrheal disease to have a negative and significant association with WHZ, and modifying effects of social and environmental factors along the disease pathway. Contemporaneous rainfall is associated with a lower likelihood of diarrheal disease in areas with excess rainfall and a higher likelihood of diarrheal disease in rainfall deficit areas. Our findings reinforce calls for targeted and situation-sensitive policies to promote child nutrition.

Diarrhea Patterns and Climate: A Spatiotemporal Bayesian Hierarchical Analysis of Diarrheal Disease in Afghanistan

Subject to a high burden of diarrheal diseases, Afghanistan is also susceptible to climate change. This study investigated the spatiotemporal distribution of diarrheal disease in the country and how associated it is with climate variables. Using monthly aggregated new cases of acute diarrhea reported between 2010 and 2016 and monthly averaged climate data at the district level, we fitted a hierarchical Bayesian spatiotemporal statistical model. We found aridity and mean daily temperature were positively associated with diarrhea incidence; every 1°C increase in mean daily temperature and 0.01-unit change in the aridity index were associated with a 0.70% (CI: 0.67%, 0.73%) increase and a 4.79% (CI: 4.30%, 5.26%) increase in the risk of diarrhea, respectively. Average annual temperature, on the other hand, was negatively associated, with a 3.7% (CI: 3.74%, 3.68) decrease in risk for every degree Celsius increase in annual average temperature. Temporally, most districts exhibited similar seasonal trends, with incidence peaking in summer, except for the eastern region where differences in climate patterns and population density may be associated with high rates of diarrhea throughout the year. The results from this study highlight the significant role of climate in shaping diarrheal patterns in Afghanistan, allowing policymakers to account for potential impacts of climate change in their public health assessments.

Association between rainfall and readmissions of rheumatoid arthritis patients: a time-stratified case-crossover analysis

It has been reported that local weather is associated with the symptoms of joint pain in patients with rheumatoid arthritis (RA), and many people believe their pain becomes worse when facing rainy days. However, limited studies explored the effects of weather on RA patients' healthcare-seeking behavior. Our study aimed to investigate the relationship between rainfall and readmission behavior of patients with RA in Hefei, China, based on hospitalization data from the First Affiliated Hospital of Anhui University of Chinese Medicine from May 2012 to June 2016 and weather data from National Meteorological Information Center during the same study period. Using a time-stratified case-crossover study design and conditional logistic regression, we found a negative association between current day rainfall and readmission (unadjusted: OR = 0.82, p < 0.05; adjusted: OR = 0.83, p < 0.1), which is contrary to our common belief. In lagged models, we observed that rainfall was significantly and positively associated with readmissions at lag 6 days (unadjusted: OR = 1.12, p < 0.1; adjusted: OR = 1.17, p < 0.05) and lag 7 days (unadjusted: OR = 1.13, p < 0.05; adjusted: OR = 1.21, p < 0.01). Additionally, stratified analyses showed the unanticipated finding was only statistically significant for younger patients (< 65 years) and females. Our study adds new evidence that the association between the healthcare-seeking behavior of patients with RA and local rainfall may be different, compared with the positive relationship between symptoms of joint pain and rainfall.

Emergency Department Visits for Acute Gastrointestinal Illness After a Major Water Pipe Break in 2010

BACKGROUND

When a water pipe breaks, contaminants can enter the drinking water system and cause waterborne illnesses such as acute gastrointestinal illness. In May 2010, a major water pipe broke near Boston, MA, and a boil water order was issued to nearly two million residents.

METHODS

Using a case-crossover study design, we examined the association between the water pipe break and subsequent emergency department visits for acute gastrointestinal illness. We identified cases of illness according to ICD-9-CM diagnosis codes and selected control dates 2 weeks before and after each case. We estimated the risk of visiting the emergency department during the 0-3 and 4-7 days after the water pipe break using conditional logistic regression models.

RESULTS

Our analysis included 5,726 emergency department visits for acute gastrointestinal illness from 3 April 2010 to 5 June 2010. Overall, there was a 1.3-fold increased odds for visiting the emergency department for acute gastrointestinal illness during the 0-3 days after the water pipe break (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 1.1, 1.4) compared with referent dates selected 2 weeks before and after. During the 4-7 days after the break, the association diminished overall (OR = 1.1; 95% CI = 0.96, 1.2). However, in communities over 12 miles from the break, the 4- to 7-day association was elevated (OR = 1.4; 95% CI = 1.1, 1.8).

CONCLUSIONS

This study suggests that a major water pipe break was associated with emergency department visits for acute gastrointestinal illness, particularly during the 0-3 days after the break, when a boil water order was in effect.

Short-term effects of moderate and severe floods on infectious diarrheal diseases in Anhui Province, China

BACKGROUND

Previous studies showed that floods can lead to diarrheal diseases outbreaks; however, the short-term effects of different severity floods on diarrheal diseases are not clear. This study aims to examine 0-14 days lagged effects of moderate and severe floods on diarrhea in Anhui Province, one heavily flood-prone area in China.

METHODS

Daily diarrheal cases from January 1, 2013 to August 31, 2017 in 16 cities of Anhui were extracted from the National Notifiable Disease Surveillance System. Meteorological data were obtained, and moderate or severe floods were identified according to Comprehensive Study Group of Major Natural Disasters of the State Science and Technology Commission in China. The quasi-Poisson generalized linear models were applied to evaluate effects of floods on daily diarrheal cases in each city with 0-14 days lag, and we divided post-flood periods into week 1 and week 2, further conducted provincial-level meta-analysis.

RESULTS

Immediate effects of floods on diarrheal diseases were observed within 7 days, and at provincial level moderate floods had a RR of 1.05 (95% CI: 1.02-1.09) and severe floods RR = 1.04 (95% CI: 1.01-1.08) controlling for population size, temperature and relative humidity etc., but less effects appeared in the second week. Impacts of flooding on diarrheal diseases varied among cities. Moderate floods in week 1 had a RR of 1.51 (95% CI: 1.29-1.78) in Bozhou, and severe floods had a RR = 1.31 (95% CI: 1.05-1.64) in Chuzhou. The severe floods may have higher RR in week 1 compared with moderate floods in Anqing (1.10 vs 1.06), Chuzhou (1.31 vs 1.07) and Luan (1.18 vs 1.00).

CONCLUSIONS

Both moderate and severe floods can significantly increase diarrheal risks in one week with regionally varied effects, and severe floods may lead higher risks. The findings have implications for preparing emergent interventions in hazard periods to reduce health risks of floods.

Tackling protein-energy under-nutrition among resource-limited people living with HIV/AIDS in Malawi using soybean-enriched maize-based stiff porridge (nsima): A pilot study

AIM

The Ministry of Health in Malawi has scaled-up antiretroviral therapy (ART) for HIV infection. However, the majority of Malawians heavily depend on maize-based stiff porridge (nsima), a protein-deficient staple, a practice that exacerbates wasting and ultimately compromises the success of ART programming. This pilot study was conducted to evaluate the efficacy of utilising soybean-enriched nsima as a strategy for managing HIV-related wasting among resource-poor people.

METHODS

A before and after designed study involving 25 wasted (<18.5 BMI (body mass index)) to normal (18.5-24.9 BMI) HIV-positive rural women (21-40 years) taking ART and provided with soybean-maize flour (20 kg/month for 3 months) prepared from hydrothermally treated soybeans and maize in the ratio of 1:4 (wt/wt). Anthropometry was performed at baseline and every month for the 3-month study period. Paired sample t-tests were used to test for changes in body mass and BMI between baseline and the subsequent months.

RESULTS

Statistically significant (P < 0.001) cumulative mean weight gain for the first, second and third month of the study were 1.6, 2.1 and 2.9 kg, respectively. The number of participants with low BMI reduced from 6/25 at baseline to 2/25 after 3 months, and the mean BMI improved from 19.3 to 21.1 kg/m2 .

CONCLUSIONS

Nsima prepared from a blend of maize and hydrothermally treated soybeans could feasibly be used to prevent and manage wasting among resource-poor people living with HIV/AIDS in sub-Saharan Africa who rely on maize as a major staple.

Extreme Precipitation, Public Health Emergencies, and Safe Drinking Water in the USA

PURPOSE OF REVIEW

This review examines the effectiveness of drinking water regulations to inform public health during extreme precipitation events. This paper estimates the vulnerability of specific populations to flooding in their public water system, reviews the literature linking precipitation to waterborne outbreaks, examines the role that Safe Drinking Water Act and Public Notification (PN) Rule have in public health emergencies, and reviews the effectiveness of the PN Rule during the 2017 Hurricane Maria in Puerto Rico.

RECENT FINDINGS

Public water systems in large metropolitan areas have substantial portions of their customer base at risk for a waterborne outbreak during a flooding event. The PN Rule are ambiguous for who is responsible for declaring a "waterborne emergency" following a natural disaster like Hurricane Maria. Revisions to the current PN Rule that mandate public notification and water quality sampling during extreme precipitation events are necessary to ensure the public is aware of their drinking water quality following these events.

Climate-driven QMRA model for selected water supply systems in Norway accounting for raw water sources and treatment processes

Formulating effective management intervention measures for water supply systems requires investigation of potential long-term impacts. This study applies an integrated multiple regression, random forest regression, and quantitative microbial risk assessment (QMRA) modelling approach to assess the effect of climate-driven precipitation on pathogen infection risks in three drinking water treatment plants (WTPs) in Norway. Pathogen removal efficacies of treatment steps were calculated using process models. The results indicate that while the WTPs investigated generally meet the current water safety guidelines, risks of Norovirus and Cryptosporidium infection may be of concern in the future. The pathogen infections attributable to current projections of average precipitation in the study locations may be low. However, the pathogen increases in the drinking water sources due to the occurrence of extreme precipitation events in the catchments could substantially increase the risks of pathogen infections. In addition, without optimal operation of the UV disinfection steps in the WTPs, both the present and potential future infection risks could be high. Therefore, the QMRA models demonstrated the need for improved optimization of key treatment steps in the WTPs, as well as implementation of stringent regulations in protecting raw water sources in the country. The variety of models applied and the pathogen: E. coli used in the study introduce some uncertainties in the results, thus, management decisions that will be based on the results should consider these limitations. Nevertheless, the integration of predictive models with QMRA as applied in this study could be a useful method for climate impact assessment in the water supply industry.

Impact of Climate Forecasts on the Microbial Quality of a Drinking Water Source in Norway Using Hydrodynamic Modeling

This study applies hydrodynamic and water quality modeling to evaluate the potential effects of local climate projections on the mixing conditions in Lake Brusdalsvatnet in Norway and the implications on the occurrence of Escherichia coli (E. coli) at the raw water intake point of the Ålesund water treatment plant in the future. The study is mainly based on observed and projected temperature, the number of E. coli in the tributaries of the lake and projected flow. The results indicate a gradual rise in the temperature of water at the intake point from the base year 2017 to year 2075. In the future, vertical circulations in spring may occur earlier while autumn circulation may start later than currently observed in the lake. The number of E. coli at the intake point of the lake is expected to marginally increase in future. By the year 2075, the models predict an approximately three-fold increase in average E. coli numbers for the spring and autumn seasons compared to current levels. The results are expected to provide the water supply system managers of Ålesund with the information necessary for long-term planning and decisions in the protection of the drinking water source. The method used here can also be applied to similar drinking water sources in Norway for developing effective risk management strategies within their catchments.

Weather and gastrointestinal disease in Spain: A retrospective time series regression study

BACKGROUND

A few studies in high-income countries have investigated the relationship between ambient temperature and/or precipitation and the occurrence of gastroenteritis. In most of the cases, hot temperatures and heavy precipitation events have been related to increases in infections. This is of concern as climate change predictions indicate an increase of those extreme events. Our aim was to evaluate the association between meteorological variables and daily gastroenteritis hospitalizations in Spain for the period 1997-2013.

METHODS

We obtained data on all hospitalizations which occurred in Spain for the study period from administrative databases and selected those with gastroenteritis as the main diagnosis. Meteorological data was obtained from the European Climate Assessment & Dataset. Daily counts of hospitalizations were linked to meteorological variables in a retrospective ecological time series study using quasi-Poisson regression models with overdispersion and applying the Distributed Lag Non-linear Model (DLNM) framework.

RESULTS

Both high and cold temperatures increased the risk of gastroenteritis hospitalizations (relative risk (RR) = 1.21, 95% confidence interval (CI): 1.09, 1.34; and RR = 1.07, 95% CI: 1.00, 1.15, respectively), whereas heavy precipitation was found protective for those hospitalizations (RR = 0.74, 95% CI: 0.63, 0.86). Hot temperatures increased hospitalizations for gastroenteritis classified as foodborne or idiopathic but not those in the group of Others, which were composed mainly of infections by rotavirus and were associated with cold temperatures.

CONCLUSIONS

Our findings suggest an important role of ambient temperatures, especially hot temperatures, in increasing gastroenteritis hospitalizations, while the exposure to heavy precipitation events pose opposite and unexpected effects on these infections.

Patterns of Host-Associated Fecal Indicators Driven by Hydrology, Precipitation, and Land Use Attributes in Great Lakes Watersheds

Fecal contamination from sewage and agricultural runoff is a pervasive problem in Great Lakes watersheds. Most work examining fecal pollution loads relies on discrete samples of fecal indicators and modeling land use. In this study, we made empirical measurements of human and ruminant-associated fecal indicator bacteria and combined these with hydrological measurements in eight watersheds ranging from predominantly forested to highly urbanized. Flow composited river samples were collected over low-flow ( n = 89) and rainfall or snowmelt runoff events ( n = 130). Approximately 90% of samples had evidence of human fecal pollution, with highest loads from urban watersheds. Ruminant indicators were found in ∼60-100% of runoff-event samples in agricultural watersheds, with concentrations and loads related to cattle density. Rain depth, season, agricultural tile drainage, and human or cattle density explained variability in daily flux of human or ruminant indicators. Mapping host-associated indicator loads to watershed discharge points sheds light on the type, level, and possible health risk from fecal pollution entering the Great Lakes and can inform total maximum daily load implementation and other management practices to target specific fecal pollution sources.

High levels of sewage contamination released from urban areas after storm events: A quantitative survey with sewage specific bacterial indicators

BACKGROUND

Past studies have demonstrated an association between waterborne disease and heavy precipitation, and climate change is predicted to increase the frequency of these types of intense storm events in some parts of the United States. In this study, we examined the linkage between rainfall and sewage contamination of urban waterways and quantified the amount of sewage released from a major urban area under different hydrologic conditions to identify conditions that increase human risk of exposure to sewage.

METHODS AND FINDINGS

Rain events and low-flow periods were intensively sampled to quantify loads of sewage based on two genetic markers for human-associated indicator bacteria (human Bacteroides and Lachnospiraceae). Samples were collected at a Lake Michigan estuary and at three river locations immediately upstream. Concentrations of indicators were analyzed using quantitative polymerase chain reaction (qPCR), and loads were calculated from streamflow data collected at each location. Human-associated indicators were found during periods of low flow, and loads increased one to two orders of magnitude during rain events from stormwater discharges contaminated with sewage. Combined sewer overflow (CSO) events increased concentrations and loads of human-associated indicators an order of magnitude greater than heavy rainfall events without CSO influence. Human-associated indicator yields (load per km2 of land per day) were related to the degree of urbanization in each watershed. Contamination in surface waters were at levels above the acceptable risk for recreational use. Further, evidence of sewage exfiltration from pipes threatens drinking water distribution systems and source water. While this study clearly demonstrates widespread sewage contamination released from urban areas, a limitation of this study is understanding human exposure and illness rates, which are dependent on multiple factors, and gaps in our knowledge of the ultimate health outcomes.

CONCLUSIONS

With the prediction of more intense rain events in certain regions due to climate change, sewer overflows and contamination from failing sewer infrastructure may increase, resulting in increases in waterborne pathogen burdens in waterways. These findings quantify hazards in exposure pathways from rain events and illustrate the additional stress that climate change may have on urban water systems. This information could be used to prioritize efforts to invest in failing sewer infrastructure and create appropriate goals to address the health concerns posed by sewage contamination from urban areas.

Temporal Variability of Faecal Contamination from On-Site Sanitation Systems in the Groundwater of Northern Thailand

We investigated the impacts of on-site sanitation systems to local groundwater. In this year-long study, we monitored the response of faecal contamination levels to hydroclimatological factors including rainfall and groundwater table. Concentration of faecal indicators-E. coli (ESC), Enterococcus (ENT), nitrate-in thirteen pairs of shallow and deep wells were determined every 7-14 days. All samples from shallow wells were tested positive for faecal contamination (ESC and ENT > 1 MPN/100 mL) but concentration varies. A maximum of 24,000 MPN/100 mL were recorded in some shallow wells. Water from deep wells showed lower susceptibility to contamination with only 4 and 23% of samples tested positive for ESC and ENT, respectively. Concentrations of ESC and ENT were lower too, with a maximum of 5 MPN/100 mL and 28 MPN/100 mL, respectively. Fluctuation in contamination among the wells was described by four archetypal responses to hydroclimatological forcing: (i) flushing during the onset of wet season, (ii) dilution over the course of the wet season, (iii) concentration during the dry season, and (iv) synoptic response to storms. Previous studies attempting to link the prevalence of faecal/waterborne diseases and temporal factors (e.g., dry vs wet season) have produced differing outcomes. Our study may help explain the relevant hydrological mechanisms leading to these varying observations. Presently, most communities in Thailand have access to 'improved' sanitation systems. However, due to the unsustainable implementation of these systems, the otherwise viable drinking-water resources in the form of the abundant local groundwater has become a genuine health hazard.

A Systematic Review of the Time Series Studies Addressing the Endemic Risk of Acute Gastroenteritis According to Drinking Water Operation Conditions in Urban Areas of Developed Countries

Time series studies (TSS) can be viewed as an inexpensive way to tackle the non-epidemic health risk from fecal pathogens in tap water in urban areas. Following the PRISMA recommendations, I reviewed TSS addressing the endemic risk of acute gastroenteritis risk according to drinking water operation conditions in urban areas of developed countries. Eighteen studies were included, covering 17 urban sites (seven in North-America and 10 in Europe) with study populations ranging from 50,000 to 9 million people. Most studies used general practitioner consultations or visits to hospitals for acute gastroenteritis (AGE) as health outcomes. In 11 of the 17 sites, a significant and plausible association was found between turbidity (or particle count) in finished water and the AGE indicator. When provided and significant, the interquartile excess of relative risk estimates ranged from 3–13%. When examined, water temperature, river flow, and produced flow were strongly associated with the AGE indicator. The potential of TSS for the study of the health risk from fecal pathogens in tap water is limited by the lack of specificity of turbidity and its site-sensitive value as an exposure proxy. Nevertheless, at the DWS level, TSS could help water operators to identify operational conditions most at risk, almost if considering other water operation indicators, in addition to turbidity, as possible relevant proxies for exposure.

Combined sewer overflow events and childhood emergency department visits: A case-crossover study

In localities with combined sewer systems, combined sewer overflow (CSO) events frequently occur following high precipitation and can result in the release of untreated sewage and industrial wastewater into surface waters. We hypothesized that either direct contact with or proximity to aerosolized CSO effluent would increase the risk for childhood emergency department (ED) visits for asthma, gastrointestinal (GI) illnesses, and skin and soft tissue infections (SSTIs) in Cincinnati, OH, USA. ED visits for 2010-2014 due to GI diseases, asthma, and SSTIs were extracted from the Cincinnati Children's Hospital Medical Center electronic health records. The location and timing of CSO events were obtained from the Metropolitan Sewer District (MSD) of Greater Cincinnati. ED visits with a residential address within 500m of a CSO site were used in a case-control crossover study with two bi-directional control periods. Conditional logistic regression models were used to estimate the risk of an ED visit associated with a CSO event at lag periods of 0 to 7days. Statistically significant elevated risks for GI-related ED visits was observed two (OR: 1.16 [95% CI 1.04,1.30]) days after CSO events. CSO events were not significantly associated with asthma- or SSTI-related ED visits, but show similar trends. Our findings suggest an increased risk for GI-related ED visits following CSO events among children who reside near CSO sites.

Sanitary Sewer Overflows and Emergency Room Visits for Gastrointestinal Illness: Analysis of Massachusetts Data, 2006-2007

BACKGROUND

Sanitary sewer overflows (SSOs) occur when untreated sewage is discharged into water sources before reaching the treatment facility, potentially contaminating the water source with gastrointestinal pathogens.

OBJECTIVES

The objective of this paper is to assess associations between SSO events and rates of gastrointestinal (GI) illness in Massachusetts.

METHODS

A case-crossover study design was used to investigate association between SSO events and emergency room (ER) visits with a primary diagnosis of gastrointestinal (GI) illness in Massachusetts for 2006-2007. ER visits for GI were considered exposed if an SSO event occurred in the county of residence within three hazard periods, 0-4 d, 5-9 d, or 10-14 d, before the visit. A time-stratified bidirectional design was used to select control days for each ER visit on the same day of the week during the same month. Fixed effect logistic regression models were used to estimate the risk of ER visits following the SSO event.

RESULTS

During the study period, there were 270 SSO events for northeastern Massachusetts and 66,460 ER admissions with GI illness listed as the primary diagnostic code. The overall odds ratio (OR) for ER visits for GI illness was 1.09 [95% confidence interval (CI): 1.03, 1.16] in the 10-14 d period following an SSO event, with positive ORs for all age groups and for three of the four counties. The 0-4 d and 5-9 d periods following an SSO event were not associated with ER visits for GI illness overall, and associations by county or age were inconsistent.

CONCLUSIONS

We demonstrated an association between SSO events and ER visits for GI illness using a case-crossover study design. In light of the aging water infrastructure in the United States and the expected increase in heavy rainfall events, our findings suggest a potential health impact associated with sewage overflows. https://doi.org/10.1289/EHP2048.

Association between Childhood Diarrhoeal Incidence and Climatic Factors in Urban and Rural Settings in the Health District of Mbour, Senegal

We assessed the association between childhood diarrhoeal incidence and climatic factors in rural and urban settings in the health district of Mbour in western Senegal. We used monthly diarrhoeal case records among children under five years registered in 24 health facilities over a four-year period (2011-2014). Climatic data (i.e., daily temperature, night temperature and rainfall) for the same four-year period were obtained. We performed a negative binomial regression model to establish the relationship between monthly diarrhoeal incidence and climatic factors of the same and the previous month. There were two annual peaks in diarrhoeal incidence: one during the cold dry season and one during the rainy season. We observed a positive association between diarrhoeal incidence and high average temperature of 36 °C and above and high cumulative monthly rainfall at 57 mm and above. The association between diarrhoeal incidence and temperature was stronger in rural compared to urban settings, while higher rainfall was associated with higher diarrhoeal incidence in the urban settings. Concluding, this study identified significant health-climate interactions and calls for effective preventive measures in the health district of Mbour. Particular attention should be paid to urban settings where diarrhoea was most common in order to reduce the high incidence in the context of climatic variability, which is expected to increase in urban areas in the face of global warming.

The Likelihood of Coliform Bacteria in NJ Domestic Wells Based on Precipitation and Other Factors

The influence of precipitation on coliform bacteria detection rates in domestic wells was investigated using data collected through the New Jersey Private Well Testing Act. Measured precipitation data from the National Weather Service (NWS) monitoring stations was compared to estimated data from the Multisensor Precipitation Estimate (MPE) in order to determine which source of data to include in the analyses. A strong concordance existed between these two precipitations datasets; therefore, MPE data was utilized as it is geographically more specific to individual wells. Statewide, 10 days of cumulative precipitation prior to testing was found to be an optimal period influencing the likelihood of coliform detections in wells. A logistic regression model was developed to predict the likelihood of coliform occurrence in wells from 10 days of cumulative precipitation data and other predictive variables including geology, season, coliform bacteria analysis method, pH, and nitrate concentration. Total coliform (TC) and fecal coliform or Escherichia coli (FC/EC) were detected more frequently when the preceding 10 days of cumulative precipitation exceeded 34.5 and 54 mm, respectively. Furthermore, the likelihood of coliform detection was highest in wells located in the bedrock region, during summer and autumn, analyzed with the enzyme substrate method, with pH between 5 and 6.99, and (for FC/EC but not TC) nitrate greater than 10 mg/L. Thus, the likelihood of coliform presence in domestic wells can be predicted from readily available environmental factors including timing and magnitude of precipitation, offering outreach opportunities and potential changes to coliform testing recommendations.

Measuring sporadic gastrointestinal illness associated with drinking water - an overview of methodologies

There is an increasing awareness that drinking water contributes to sporadic gastrointestinal illness (GI) in high income countries of the northern hemisphere. A literature search was conducted in order to review: (1) methods used for investigating the effects of public drinking water on GI; (2) evidence of possible dose-response relationship between sporadic GI and drinking water consumption; and (3) association between sporadic GI and factors affecting drinking water quality. Seventy-four articles were selected, key findings and information gaps were identified. In-home intervention studies have only been conducted in areas using surface water sources and intervention studies in communities supplied by ground water are therefore needed. Community-wide intervention studies may constitute a cost-effective alternative to in-home intervention studies. Proxy data that correlate with GI in the community can be used for detecting changes in the incidence of GI. Proxy data can, however, not be used for measuring the prevalence of illness. Local conditions affecting water safety may vary greatly, making direct comparisons between studies difficult unless sufficient knowledge about these conditions is acquired. Drinking water in high-income countries contributes to endemic levels of GI and there are public health benefits for further improvements of drinking water safety.

Mobilisation of microbial indicators, microbial source tracking markers and pathogens after rainfall events

Climate change is expected to affect the Mediterranean region by causing an increase in the number of heavy rainfall events. The aim of this study was to assess the effect of extreme river flow variations due to rainfall on the persistence and mobilisation of various microorganisms. These included faecal pollution indicators (Escherichia coli (EC), somatic coliphages (SOMCPH) and sulphite reducing clostridia spores (SRC)), microbial source tracking indicators (Bacteroides thetaiotaomicron GA17 strain phages (GA17PH) and sorbitol fermenting bifidobacteria (SFBIF)), and two pathogens (Salmonella spp and Enterovirus). Water and sediment samples were taken at different distances from the river before and after heavy rainfall events. The microbial load was higher in sediment samples closer to the river course. The concentration of some faecal indicators (EC and SFBIF) increased in sediments and river water after rainfall events, whereas the most conservative parameter (SRC) showed almost no variation. After rainfall, the indicators persisted at a different rate. Salmonella spp and Enterovirus were detected in some samples but always at lower concentrations than the microbial indicators. In conclusion, sediments are reservoirs of faecal and MST indicators and pathogens and could therefore pose a risk of pathogen dissemination.

Effect of drinking water source on associations between gastrointestinal illness and heavy rainfall in New Jersey

Gastrointestinal illness (GI) has been associated with heavy rainfall. Storm events and periods of heavy rainfall and runoff can result in increased microbiological contaminants in raw water. Surface water supplies are open to the environment and runoff can directly influence the presence of contaminants. A time-stratified bi-directional case-crossover study design was used to estimate associations of heavy rainfall and hospitalizations for GI. Cases of GI were identified as in-patient hospitalization with a primary diagnosis of infectious disease associated diarrhea [ICD-9 codes: specified gastrointestinal infections 001–009.9 or diarrhea 787.91] among the residents of New Jersey from 2009 to 2013 resulting in a final sample size of 47,527 cases. Two control days were selected on the same days of the week as the case day, within fixed 21-day strata. Conditional logistic regression was used to estimate odds ratios controlling for temperature and humidity. To determine potential effect modification estimates were stratified by season (warm or cold) and drinking water source (groundwater, surface water, or ‘other’ category). Stratified analyses by drinking water source and season identified positive associations of rainfall and GI hospitalizations in surface water systems during the warm season with no lag (OR = 1.12, 95% CI 1.05–1.19) and a 2-day lag (OR = 1.09, 95% CI 1.03–1.16). Positive associations in ‘Other’ water source areas (served by very small community water systems, private wells, or unknown) during the warm season with a 4-day lag were also found. However, there were no statistically significant positive associations in groundwater systems during the warm season. The results suggest that water systems with surface water sources can play an important role in preventing GI hospitalizations during and immediately following heavy rainfall. Regulators should work with water system providers to develop system specific prevention techniques to limit the impact of heavy rainfall on public health.

Heavy rainfall and risk of infectious intestinal diseases in the most populous city in Vietnam

The association between heavy rainfall and infectious intestinal diseases (IID) has not been well described and little research has been conducted in developing countries. This study examines the association between heavy rainfall and hospital admissions for IID in Ho Chi Minh City, the most populous city in Vietnam. An interrupted time-series method was used to examine the effect of each individual heavy rainfall event (HRE) on IID. The percentage changes in post-HRE level and trends of IID were estimated for 30days following each HRE. Then a random-effect meta-analysis was used to quantify the pooled estimate of effect sizes of all HREs on IID. The pooled estimates were calculated over a 21day lag period. The effects of a HRE on IID varied across individual HREs. The pooled estimates indicate that the levels of IID following a HRE increased from 7.3% to 13.5% for lags from 0 to 21days, however statistically significant increases were only observed for lags from 4 to 6days (13.5%, 95%CI: 1.4-25.4; 13.3%, 95%CI: 1.5-25.0; and 12.9%, 95%CI: 1.6-24.1 respectively). An average decrease of 0.11% (95%CI: -0.55-0.33) per day was observed for the post-HRE trend. This finding has important implications for the projected impacts on residents living in this city which is highly vulnerable to increased heavy rainfall associated with climate change. Adaptation and intervention programs should be developed to prevent this additional burden of disease and to protect residents from the adverse impacts of extreme weather events.

Projections of hepatitis A virus infection associated with flood events by 2020 and 2030 in Anhui Province, China

Assessing and responding to health risk of climate change is important because of its impact on the natural and societal ecosystems. More frequent and severe flood events will occur in China due to climate change. Given that population is projected to increase, more people will be vulnerable to flood events, which may lead to an increased incidence of HAV infection in the future. This population-based study is going to project the future health burden of HAV infection associated with flood events in Huai River Basin of China. The study area covered four cities of Anhui province in China, where flood events were frequent. Time-series adjusted Poisson regression model was developed to quantify the risks of flood events on HAV infection based on the number of daily cases during summer seasons from 2005 to 2010, controlling for other meteorological variables. Projections of HAV infection in 2020 and 2030 were estimated based on the scenarios of flood events and demographic data. Poisson regression model suggested that compared with the periods without flood events, the risks of severe flood events for HAV infection were significant (OR = 1.28, 95 % CI 1.05-1.55), while risks were not significant from moderate flood events (OR = 1.16, 95 % CI 0.72-1.87) and mild flood events (OR = 1.14, 95 % CI 0.87-1.48). Using the 2010 baseline data and the flood event scenarios (one severe flood event), increased incidence of HAV infection were estimated to be between 0.126/10⁵ and 0.127/10⁵ for 2020. Similarly, the increased HAV infection incidence for 2030 was projected to be between 0.382/10⁵ and 0.399/10⁵. Our study has, for the first time, quantified the increased incidence of HAV infection that will result from flood events in Anhui, China, in 2020 and 2030. The results have implications for public health preparation for developing public health responses to reduce HAV infection during future flood events.

Association between heavy precipitation events and waterborne outbreaks in four Nordic countries, 1992-2012

We conducted a matched case-control study to examine the association between heavy precipitation events and waterborne outbreaks (WBOs) by linking epidemiological registries and meteorological data between 1992 and 2012 in four Nordic countries. Heavy precipitation events were defined by above average (exceedance) daily rainfall during the preceding weeks using local references. We performed conditional logistic regression using the four previous years as the controls. Among WBOs with known onset date (n = 89), exceedance rainfall on two or more days was associated with occurrence of outbreak, OR = 3.06 (95% CI 1.38-6.78), compared to zero exceedance days. Stratified analyses revealed a significant association with single household water supplies, ground water as source and for outbreaks occurring during spring and summer. These findings were reproduced in analyses including all WBOs with known outbreak month (n = 186). The vulnerability of single households to WBOs associated with heavy precipitation events should be communicated to homeowners and implemented into future policy planning to reduce the risk of waterborne illness.

Quantification of human-associated fecal indicators reveal sewage from urban watersheds as a source of pollution to Lake Michigan

Sewage contamination of urban waterways from sewer overflows and failing infrastructure is a major environmental and public health concern. Fecal coliforms (FC) are commonly employed as fecal indicator bacteria, but do not distinguish between human and non-human sources of fecal contamination. Human Bacteroides and human Lachnospiraceae, two genetic markers for human-associated indicator bacteria, were used to identify sewage signals in two urban rivers and the estuary that drains to Lake Michigan. Grab samples were collected from the rivers throughout 2012 and 2013 and hourly samples were collected in the estuary across the hydrograph during summer 2013. Human Bacteroides and human Lachnospiraceae were highly correlated with each other in river samples (Pearson's r = 0.86), with average concentrations at most sites elevated during wet weather. These human indicators were found during baseflow, indicating that sewage contamination is chronic in these waterways. FC are used for determining total maximum daily loads (TMDLs) in management plans; however, FC concentrations alone failed to prioritize river reaches with potential health risks. While 84% of samples with >1000 CFU/100 ml FC had sewage contamination, 52% of samples with moderate (200-1000 CFU/100 ml) and 46% of samples with low (<200 CFU/100 ml) FC levels also had evidence of human sewage. Load calculations in the in the Milwaukee estuary revealed storm-driven sewage contamination varied greatly among events and was highest during an event with a short duration of intense rain. This work demonstrates urban areas have unrecognized sewage inputs that may not be adequately prioritized for remediation by the TMDL process. Further analysis using these approaches could determine relationships between land use, storm characteristics, and other factors that drive sewage contamination in urban waterways.

Rainfall variation and child health: effect of rainfall on diarrhea among under 5 children in Rwanda, 2010

Background

Diarrhea among children under 5 years of age has long been a major public health concern. Previous studies have suggested an association between rainfall and diarrhea. Here, we examined the association between Rwandan rainfall patterns and childhood diarrhea and the impact of household sanitation variables on this relationship.

Methods

We derived a series of rain-related variables in Rwanda based on daily rainfall measurements and hydrological models built from daily precipitation measurements collected between 2009 and 2011. Using these data and the 2010 Rwanda Demographic and Health Survey database, we measured the association between total monthly rainfall, monthly rainfall intensity, runoff water and anomalous rainfall and the occurrence of diarrhea in children under 5 years of age.

Results

Among the 8601 children under 5 years of age included in the survey, 13.2 % reported having diarrhea within the 2 weeks prior to the survey. We found that higher levels of runoff were protective against diarrhea compared to low levels among children who lived in households with unimproved toilet facilities (OR = 0.54, 95 % CI: [0.34, 0.87] for moderate runoff and OR = 0.50, 95 % CI: [0.29, 0.86] for high runoff) but had no impact among children in household with improved toilets.

Conclusion

Our finding that children in households with unimproved toilets were less likely to report diarrhea during periods of high runoff highlights the vulnerabilities of those living without adequate sanitation to the negative health impacts of environmental events.

Untangling the Impacts of Climate Change on Waterborne Diseases: a Systematic Review of Relationships between Diarrheal Diseases and Temperature, Rainfall, Flooding, and Drought

Global climate change is expected to affect waterborne enteric diseases, yet to date there has been no comprehensive, systematic review of the epidemiological literature examining the relationship between meteorological conditions and diarrheal diseases. We searched PubMed, Embase, Web of Science, and the Cochrane Collection for studies describing the relationship between diarrheal diseases and four meteorological conditions that are expected to increase with climate change: ambient temperature, heavy rainfall, drought, and flooding. We synthesized key areas of agreement and evaluated the biological plausibility of these findings, drawing from a diverse, multidisciplinary evidence base. We identified 141 articles that met our inclusion criteria. Key areas of agreement include a positive association between ambient temperature and diarrheal diseases, with the exception of viral diarrhea and an increase in diarrheal disease following heavy rainfall and flooding events. Insufficient evidence was available to evaluate the effects of drought on diarrhea. There is evidence to support the biological plausibility of these associations, but publication bias is an ongoing concern. Future research evaluating whether interventions, such as improved water and sanitation access, modify risk would further our understanding of the potential impacts of climate change on diarrheal diseases and aid in the prioritization of adaptation measures.

The association of weather on pediatric emergency department visits in Changwon, Korea (2005-2014)

BACKGROUND

It is widely believed that patients are less likely to visit hospitals during bad weather. We hypothesized that weather and emergency department (ED) visits are associated. Thus, we investigated the association between pediatric ED visits and weather, and sought to determine whether admissions to the ED are affected by meteorological factors.

METHODS

We retrospectively analyzed all 87,242 emergency visits to Samsung Changwon Hospital by pediatric patients under 19years of age from January 2005 to December 2014. ED visits were categorized by disease. We used Poisson regression and generalized linear model to examine the relationships between current weather and ED visits. Additionally a distributed lag non-linear model was used to investigate the effect of weather on ED visits.

RESULTS

During this 10-year study period, the average temperature and diurnal temperature range (DTR) were 14.7°C and 8.2°C, respectively. There were 1,145days of rain or snow (31.4%) during the 3,652-day study period. The volume of ED visits decreased on days of rain or snow. Additionally ED visits increased 2days after rainy or snowy days. The volume of ED visits increased 1.013 times with every 1°C increase in DTR. The volume of ED visits by patients with trauma, digestive diseases, and respiratory diseases increased when DTR was over 10°C. As rainfall increased to over 25mm, the ward admission rate (23.8%, p=0.018) of ED patients increased significantly.

CONCLUSION

The volume of ED visits decreased on days of rain or snow and the ED visits were increased 2days after rainy or snowy days. The volume of ED visits increased for every 1°C increase in DTR.

Did summer weather factors affect gastrointestinal infection hospitalizations in New York State?

BACKGROUND

Gastrointestinal infections, a substantial public health problem worldwide, have been associated with single weather factors but the joint effect of multiple weather factors on gastrointestinal infections remains unclear.

METHODS

We conducted a retrospective time-series analysis to investigate effects of weather conditions on hospitalizations for gastrointestinal infections (GIH) in New York State in July and August from 1991 to 2004. Applying generalized additive model (GAM), we evaluated the associations between daily GIH count and multiple weather factors including temperature, humidity, and precipitation (0-10 lag days), adjusting for long term trend, seasonality, and calendar effects.

RESULTS

Maximum temperature, minimum temperature, and maximum universal apparent temperature (UAT) showed that each °C increase in temperature was significantly associated with an increase (0.70-0.96%) in daily GIH count, with the greatest impacts observed at lag 1. Extreme heat (EH: >90th percentile) (3.68% at lag 1) and precipitation (0.31% at lag 4) showed larger impacts on increases of GIH and a clear dose-response relationship for EH. Stratified analyses showed that the impacts of extreme heat on GIH tend to be greater among Hispanics, blacks, females, and those with bacterial infections.

CONCLUSION

We found that high maximum and minimum temperature, UAT, precipitation, and extreme heat in summer significantly increased the risks of GIH in NYS. Our findings also suggest that bacteria might be a significant cause for GIH in the summer, and minority, female and those with bacterial infection may be more vulnerable to heat's effects on GIH.

Global Climate Change and Children's Health

Rising global temperature is causing major physical, chemical, and ecological changes across the planet. There is wide consensus among scientific organizations and climatologists that these broad effects, known as climate change, are the result of contemporary human activity. Climate change poses threats to human health, safety, and security. Children are uniquely vulnerable to these threats. The effects of climate change on child health include physical and psychological sequelae of weather disasters, increased heat stress, decreased air quality, altered disease patterns of some climate-sensitive infections, and food, water, and nutrient insecurity in vulnerable regions. Prompt implementation of mitigation and adaptation strategies will protect children against worsening of the problem and its associated health effects. This technical report reviews the nature of climate change and its associated child health effects and supports the recommendations in the accompanying policy statement on climate change and children's health.

Extreme Precipitation and Emergency Room Visits for Gastrointestinal Illness in Areas with and without Combined Sewer Systems: An Analysis of Massachusetts Data, 2003-2007

BACKGROUND

Combined sewer overflows (CSOs) occur in combined sewer systems when sewage and stormwater runoff are released into water bodies, potentially contaminating water sources. CSOs are often caused by heavy precipitation and are expected to increase with increasing extreme precipitation associated with climate change.

OBJECTIVES

The aim of this study was to assess whether the association between heavy rainfall and rate of emergency room (ER) visits for gastrointestinal (GI) illness differed in the presence of CSOs.

METHODS

For the study period 2003-2007, time series of daily rate of ER visits for GI illness and meteorological data were organized for three exposure regions: a) CSOs impacting drinking water sources, b) CSOs impacting recreational waters, c) no CSOs. A distributed lag Poisson regression assessed cumulative effects for an 8-day lag period following heavy (≥ 90th and ≥ 95th percentile) and extreme (≥ 99th percentile) precipitation events, controlling for temperature and long-term time trends.

RESULTS

The association between extreme rainfall and rate of ER visits for GI illness differed among regions. Only the region with drinking water exposed to CSOs demonstrated a significant increased cumulative risk for rate (CRR) of ER visits for GI for all ages in the 8-day period following extreme rainfall: CRR: 1.13 (95% CI: 1.00, 1.28) compared with no rainfall.

CONCLUSIONS

The rate of ER visits for GI illness was associated with extreme precipitation in the area with CSO discharges to a drinking water source. Our findings suggest an increased risk for GI illness among consumers whose drinking water source may be impacted by CSOs after extreme precipitation.

CITATION

Jagai JS, Li Q, Wang S, Messier KP, Wade TJ, Hilborn ED. 2015. Extreme precipitation and emergency room visits for gastrointestinal illness in areas with and without combined sewer systems: an analysis of Massachusetts data, 2003-2007. Environ Health Perspect 123:873-879; http://dx.doi.org/10.1289/ehp.1408971.

Spatial and temporal variation in the association between temperature and salmonellosis in NZ

OBJECTIVE

Modelling the relationship between weather, climate and infectious diseases can help identify high-risk periods and provide understanding of the determinants of longer-term trends. We provide a detailed examination of the non-linear and delayed association between temperature and salmonellosis in three New Zealand cities (Auckland, Wellington and Christchurch).

METHODS

Salmonella notifications were geocoded to the city of residence for the reported case. City-specific associations between weekly maximum temperature and the onset date for reported salmonella infections (1997-2007) were modelled using non-linear distributed lag models, while controlling for season and long-term trends.

RESULTS

Relatively high temperatures were positively associated with infection risk in Auckland (n=3,073) and Christchurch (n=880), although the former showed evidence of a more immediate relationship with exposure to high temperatures. There was no significant association between temperature and salmonellosis risk in Wellington.

CONCLUSIONS

Projected increases in temperature with climate change may have localised health impacts, suggesting that preventative measures will need to be region-specific. This evidence contributes to the increasing concern over the public health impacts of climate change.

Precipitation and primary health care visits for gastrointestinal illness in Gothenburg, Sweden

BACKGROUND

The river Göta Älv is a source of freshwater for the City of Gothenburg, Sweden, and we recently identified a clear influence of upstream precipitation on concentrations of indicator bacteria in the river water, as well as an association with the daily number of phone calls to the nurse advice line related to acute gastrointestinal illnesses (AGI calls). This study aimed to examine visits to primary health-care centers owing to similar symptoms (AGI visits) in the same area, to explore associations with precipitation, and to compare variability in AGI visits and AGI calls.

METHODS

We obtained data covering six years (2007-2012) of daily AGI visits and studied their association with prior precipitation (0-28 days) using a distributed lag nonlinear Poisson regression model, adjusting for seasonal patterns and covariates. In addition, we studied the effects of prolonged wet and dry weather on AGI visits. We analyzed lagged short-term relations between AGI visits and AGI calls, and we studied differences in their seasonal patterns using a binomial regression model.

RESULTS

The study period saw a total of 17,030 AGI visits, and the number of daily visits decreased on days when precipitation occurred. However, prolonged wet weather was associated with an elevated number of AGI visits. Differences in seasonality patterns were observed between AGI visits and AGI calls, as visits were relatively less frequent during winter and relatively more frequent in August, and only weak short-term relations were found.

CONCLUSION

AGI visits and AGI calls seems to partly reflect different types of AGI illnesses, and the patients' choice of medical contact (in-person visits versus phone calls) appears to depend on current weather conditions. An association between prolonged wet weather and increased AGI visits supports the hypothesis that the drinking water is related to an increased risk of AGI illnesses.