Assessing the Association between Thermotolerant Coliforms in Drinking Water and Diarrhea: An Analysis of Individual-Level Data from Multiple Studies

Prevalence and risk factors associated with under-five years children diarrhea in Malawi: Application of survey logistic regression

Background

Diarrhea is a leading cause of illness and mortality among children under five, posing a significant public health challenge in Malawi. The current study assesses the prevalence and risk factors linked to diarrhea among under-five children in Malawi.

Method

The researcher used the Malawi Multiple Indicator Cluster Survey (MICS) 2019-20 as the dataset for this study. Due to the complex sampling design, survey logistic regression was used to accomplish the study objectives. The sample size was 15569 children who were aged under five.

Results

The study found that the prevalence of diarrhea was 24.9%, with a higher percentage observed among children aged 12-23 months (38.5%) compared to other age groups. Additionally, children from the southern region had a higher prevalence of diarrhea at 27% compared to those from the northern region at 19.3%. Children from the poorest households also had a higher prevalence of diarrhea at 28.9% compared to those from the richest households at 22.6%. Furthermore, children with fever had a higher prevalence of diarrhea at 33.3% compared to those who did not have fever at 19.4%.

Conclusion

The current study concluded that the prevalence of diarrhea was higher among children aged 12-23 months. Subsequently, policymakers should apply policies to reduce this high prevalence among this age group of children. In addition, the government needs special consideration in diarrhea control for children from the southern region because of the high prevalence of the disease compared to the other regions in Malawi. My study can help policymakers understand the scope and nature of the problem, which can notify the development of policies and programs intended to decrease the prevalence of risk factors and enhance child health outcomes.

A multilevel analysis of the predictors of diarrhea among children under 5 years of age in Eswatini

Diarrhea remains a public health challenge and persistently affect children under 5 years of age, primarily in developing countries. The aim of the study was to investigate the effects of individual, household and community level factors on child diarrhea. Using combined data 2010 and 2014 Eswatini Multiple Indicator Cluster surveys, data for 4,363 under five children was analysed. Univariable, bivariable and multivariable multilevel logistic regression models were used for data analysis. We found that the prevalence of diarrhea was 16.2%, (95% confidence interval (CI): 15.3-18.1). Higher odds of diarrhea were observed among children aged 6-11 months (AOR: 2.67, 95% CI: 1.93, 3.71) and 12-23 months (AOR=2.12, 95% CI: 1.56, 2.87) compared to those aged less than 6 months. However, lower odds of diarrhea were observed among children aged 36-47 months (AOR=0.68, 95% CI: 0.48, 0.97) and 48-59 months (AOR=0.39, 95% CI: 0.26, 0.58), compared to children aged less than 6 months. Children born to mothers aged 35-39 years had lower odds of having diarrhea, (AOR=0.48, 95%CI: 0.30, 0.79) compared to those born to mothers aged 15-19 years. Higher odds of having diarrhea were observed among children from communities with a low proportion of households with improved toilet facility (AOR=1.29, 95% CI: 1.01, 1.66) compared to those from communities with a high proportion of households with improved toilet facility. We found that individual- and community-level factors were associated with child diarrhea in Eswatini. Programmes and policies that aim to mitigate child morbidity due to diarrhea should pay attention to the individual and community factors.

Prevalence and Antimicrobial Susceptibility Profile of Salmonella and Shigella among Diarrheic Patients Attending Selected Health Facilities in Addis Ababa, Ethiopia

Diarrhea is one of the important public health problems in developing countries. Salmonella and Shigella species are the major bacterial causal agents of diarrhea. The increasing burden of antimicrobial resistance is posing difficulty in the treatment of these pathogens. This study aimed to assess the occurrence of Salmonella and Shigella in the feces of diarrheic patients receiving health services in Addis Ababa, Ethiopia, and to determine their antimicrobial susceptibility profile. A cross-sectional study involving 13 health centers was conducted where 428 diarrheic patients were recruited. Standard microbiology techniques were used to isolate Salmonella and Shigella from stool samples. In addition, Salmonella isolates were confirmed by polymerase chain reaction (PCR). The Kirby-Bauer disc diffusion method was employed to assess susceptibility to 11 antimicrobials for each of the Salmonella and Shigella isolates. The prevalence of Salmonella and Shigella spp. among diarrheic patients was 8.4%; n = 36 and 5.6%; n = 24, respectively. Thirty (83.3%) of Salmonella isolates were susceptible to all antimicrobials tested, whereas 4 (10.8%) of isolates were resistant to 2 or more antimicrobials and 2 (5.6%) were multidrug resistant. Resistance to ampicillin was recorded in only one (2.7%) of Salmonella isolates; however, resistance to ampicillin was recorded in 12 (50%) of the Shigella isolates. Half of the Shigella isolates (n = 12) were resistant to 2 or more antimicrobials while 5 (20.8%) of them were resistant to 3 or more antimicrobials. The overall rate of resistance to antimicrobials was more common in Shigella compared to Salmonella isolates. In conclusion, Salmonella and Shigella were isolated from the feces of diarrheic patients, with a higher rate of antimicrobial resistance in Shigella isolates, which could make the treatment of shigellosis challenging. Therefore, increasing hygienic practices during food preparation to reduce the burden of Salmonella and Shigella infection and prudent use of antimicrobials are recommended to limit the spread of antimicrobial resistant strains.

Effects of adding household water filters to Rwanda's Community-Based Environmental Health Promotion Programme: a cluster-randomized controlled trial in Rwamagana district

Unsafe drinking water remains a major cause of mortality and morbidity. While Rwanda's Community-Based Environmental Health Promotion Programme (CBEHPP) promotes boiling and safe storage, previous research found these efforts to be ineffective in reducing fecal contamination of drinking water. We conducted a cluster randomized control led trial to determine if adding a household water filter with safe storage to the CBEHPP would improve drinking water quality and reduce child diarrhea. We enrolled 1,199 households with a pregnant person or child under 5 across 60 randomly selected villages in Rwamagana district. CBEHPP implementers distributed and promoted water purifiers to a random half of villages. We conducted two unannounced follow-up visits over 13-16 months after the intervention delivery. The intervention reduced the proportions of households with detectable E. coli in drinking water samples (primary outcome) by 20% (PR 0.80, 95% CI 0.74-0.87, p < 0.001) and with moderate and higher fecal contamination (≥10 CFU/100 mL) by 35% (PR 0.65, 95% CI 0.57-0.74, p < 0.001). The proportion of children under 5 experiencing diarrhea in the last week was reduced by 49% (aPR 0.51, 95%CI 0.35-0.73, p < 0.001). Our findings identify an effective intervention for improving water quality and child health that can be added to the CBEHPP.

A continuous, in-situ, near-time fluorescence sensor coupled with a machine learning model for detection of fecal contamination risk in drinking water: Design, characterization and field validation

We designed and validated a sensitive, continuous, in-situ, remotely reporting tryptophan-like fluorescence sensor and coupled it with a machine learning model to predict high-risk fecal contamination in water (>10 colony forming units (CFU)/100mL E. coli). We characterized the sensor's response to multiple fluorescence interferents with benchtop analysis. The sensor's minimum detection limit (MDL) of tryptophan dissolved in deionized water was 0.05 ppb (p <0.01) and its MDL of the correlation to E. coli present in wastewater effluent was 10 CFU/100 mL (p <0.01). Fluorescence response declined exponentially with increased water temperature and a correction factor was calculated. Inner filter effects, which cause signal attenuation at high concentrations, were shown to have negligible impact in an operational context. Biofouling was demonstrated to increase the fluorescence signal by approximately 82% in a certain context, while mineral scaling reduced the sensitivity of the sensor by approximately 5% after 24 hours with a scaling solution containing 8 times the mineral concentration of the Colorado River. A machine learning model was developed, with TLF measurements as the primary feature, to output fecal contamination risk levels established by the World Health Organization. A training and validation data set for the model was built by installing four sensors on Boulder Creek, Colorado for 88 days and enumerating 298 grab samples for E. coli with membrane filtration. The machine learning model incorporated a proxy feature for fouling (time since last cleaning) which improved model performance. A binary classification model was able to predict high risk fecal contamination with 83% accuracy (95% CI: 78% - 87%), sensitivity of 80%, and specificity of 86%. A model distinguishing between all World Health Organization established risk categories performed with an overall accuracy of 64%. Integrating TLF measurements into an ML model allows for anomaly detection and noise reduction, permitting contamination prediction despite biofilm or mineral scaling formation on the sensor's lenses. Real-time detection of high risk fecal contamination could contribute to a major step forward in terms of microbial water quality monitoring for human health.

An integrative water quality evaluation in two surface water bodies from a tropical agricultural region in Cartago, Costa Rica

A monitoring study was carried out in two micro-catchments in the Reventazón basin, in Northern Cartago, Costa Rica; pesticide occurrence and water quality were analyzed. Twelve pesticides were detected, five insecticides (chlorpyrifos, carbofuran, cypermethrin, imidacloprid, and oxamyl), four fungicides (carbendazim, imazalil, metalaxyl, and thiabendazole), and three herbicides (diuron, linuron, and terbutryn); eight of them presented risk quotients RQ >1, which implies a high risk for the environment. The water quality evaluation included fourteen physicochemical and microbiological parameters, out of which thermotolerant coliforms, nitrate, and total phosphorus exceeded a selected threshold value in every sample. Five metals were also included in the evaluation, Pb was the most frequent, followed by few detections of Cd, Cu, and Cr. Four water quality indexes (WQIs) were applied, two of them, the CCME WQI, based on physicochemical parameters, and the BMWP-CR WQI, based on benthic macroinvertebrate recount adapted to Costa Rican species, categorized all the sampling points as "bad" and "very bad" quality. This work of monitoring is important in the Latin American region, where there is a lack of information for regulation improvement and management decisions. These results showed poor management of the micro-catchments in this agricultural rural area.

Diarrhea and associated factors among under five children in sub-Saharan Africa: Evidence from demographic and health surveys of 34 sub-Saharan countries

INTRODUCTION

Diarrhea is responsible for the death of more than 90% of under-five children in low and lower-middle income countries. Regionally, South Asia and sub-Saharan Africa accounted for 88% of deaths with the same age group. Therefore, the aim of this study was to determine the prevalence and associated factors of diarrhea among children under-five years in sub-Saharan Africa.

METHODS

The appended, most recent demographic and health survey datasets of 34 sub-Saharan African countries were used to determine the prevalence and associated factors of diarrhea among under-five children in the region. A total weighted sample of 330,866 under-five children were included in the study. Both bivariable and multivariable multilevel logistic regression were done to determine the associated factors of diarrhea among under five children in sub-Saharan Africa. The Odds Ratio (OR) with a 95% Confidence Interval (CI) was calculated for those potential factors included in the final model.

RESULT

The overall prevalence of diarrhea in this study was 15.3% (95% CI: 15.1-15.4). Those children of mothers aged 15-24 (AOR = 1.26; 95% CI: 1.23, 1.30) and 25-34 years (AOR = 1.15; 95%CI: 1.12, 1.18), those children of mothers with no education (AOR = 1.69; 95%CI: 1.57-1.82), primary education (AOR = 1.73; 95%CI: 1.61-1.86) and secondary education (AOR = 1.49; 95%CI: 1.38-1.59) had higher odds of having diarrhea. Those children from poorest (AOR = 1.14; 95%CI: 1.10, 1.19), poorer (AOR = 1.12; 95%CI: 1.08-1.17), middle (AOR = 1.06; 95%CI: 1.02, 1.10), and richer (AOR = 1.14; 95%CI: 1.04-1.12) households had higher chance of having diarrhea compared to their counterparts.

CONCLUSION

This study found that the prevalence of childhood diarrhea morbidity in sub-Saharan Africa was high. Maternal age, wealth index, maternal education, maternal occupation, age of child, time of initiation of breast feeding and time to get water source were significantly associated with diarrhea. Therefore, intervention through health education and health promotion for mothers/caretakers who are poor, less educated, and young should be designed to prevent diarrhea in the region.

Is direct-drinking water safe for children? An analysis of direct-drinking water quality and its risk factors in Shanghai elementary and middle schools

BACKGROUND

Drinking water quality for children should be higher than adults due to both behavioral and physiological factors. Thus, to provide enough, safe, and easily accessible drinking water for children at schools, the Shanghai Municipal Government initiated a direct-drinking water project in 2013. However, there has been no study so far to assess the quality of direct-drinking water or to investigate its risk factors in Shanghai elementary and middle schools.

METHODS

In the present study, we selected direct-drinking water equipment from 183 elementary and middle schools (17% of total) in Shanghai to detect the colony-forming units (CFU), residual chlorine, chemical oxygen demand (COD), and turbidity of water samples, and analyzed the risk factors of its quality using both simple and multiple linear regression analysis.

RESULTS

Results showed that the CFU, residual chlorine, COD, and turbidity of direct-drinking water in Shanghai elementary and middle schools ranged from <LOD->300 cfu/mL, <LOD-0.670 mg/L, 0.090-2.710 mg/L, and 0.100-2.050 NTU, respectively. The results of simple linear regression analysis indicated that the CFU of direct-drinking water significantly increased when water temperature was between 25 and 60 °C (β = 19.862, p = 0.030), but it was decreased at 60-100 °C (β = - 16.387, p = 0.046). Additionally, the CFU was higher in elementary schools than middle schools, which was also affected by faucet type and water treatment technology (p = 0.006, 0.012 and 0.042, respectively). The residual chlorine in direct-drinking water significantly increased when there was no toilet within 10 m (β = 0.012, p = 0.045). The COD of direct-drinking water was significantly higher in rural areas and in warm water, compared to urban areas (p = 0.033) and room temperature water (p = 0.000), respectively. The turbidity of direct-drinking water was significantly higher in urban areas and water using UF/MF technology, compared to rural areas (p = 0.030) and RO technology (p = 0.009), respectively. The results of multiple linear regressions analysis drew the same conclusions.

CONCLUSIONS

In order to improve the quality of direct-drinking water, the equipment should be as far away from toilet as possible and direct-drinking water should be kept at room temperature or heated at high temperature (over 60 °C). Furthermore, sanitary standards of direct-drinking water quality and relevant laws and regulations should be established and implemented as soon as possible. Our study demonstrates that it is critical to improve direct-drinking water quality and ensure the safety of drinking water in elementary and middle schools in Shanghai.

Measuring Environmental Exposure to Enteric Pathogens in Low-Income Settings: Review and Recommendations of an Interdisciplinary Working Group

Infections with enteric pathogens impose a heavy disease burden, especially among young children in low-income countries. Recent findings from randomized controlled trials of water, sanitation, and hygiene interventions have raised questions about current methods for assessing environmental exposure to enteric pathogens. Approaches for estimating sources and doses of exposure suffer from a number of shortcomings, including reliance on imperfect indicators of fecal contamination instead of actual pathogens and estimating exposure indirectly from imprecise measurements of pathogens in the environment and human interaction therewith. These shortcomings limit the potential for effective surveillance of exposures, identification of important sources and modes of transmission, and evaluation of the effectiveness of interventions. In this review, we summarize current and emerging approaches used to characterize enteric pathogen hazards in different environmental media as well as human interaction with those media (external measures of exposure), and review methods that measure human infection with enteric pathogens as a proxy for past exposure (internal measures of exposure). We draw from lessons learned in other areas of environmental health to highlight how external and internal measures of exposure can be used to more comprehensively assess exposure. We conclude by recommending strategies for advancing enteric pathogen exposure assessments.

Faecal contamination of the environment and child health: a systematic review and individual participant data meta-analysis

BACKGROUND

Exposure to faecal contamination is believed to be associated with child diarrhoea and possibly stunting; however, few studies have explicitly measured the association between faecal contamination and health. We aimed to assess individual participant data (IPD) across multiple trials and observational studies to quantify the relationship for common faecal-oral transmission pathways.

METHODS

We did a systematic review and meta-analysis of IPD from studies identified in an electronic search of PubMed, Web of Science, and Embase on May 21, 2018. The search was done in English, but full texts published in French, Portuguese, and Spanish were also reviewed. Eligible studies quantified (1) household-level faecal indicator bacteria concentrations along common faecal-oral transmission pathways of drinking water, soil, or food, on children's hands or fomites, or fly densities in food preparation areas; and (2) individual-level diarrhoea or linear growth measures for children younger than 5 years in low-income and middle-income countries. For the diarrhoea analysis, all definitions of diarrhoea were eligible but studies were excluded if they used a recall period longer than 7 days. For the linear growth analysis (using height-for-age Z scores [HAZ]), cross-sectional studies were excluded, because of the absence of longitudinal environmental contamination data measured before the growth outcomes. We used multilevel generalised mixed-effects models to estimate the odds ratio (OR) for diarrhoea and the difference in HAZ scores for individual studies associated with a 1-log₁₀ higher measure of faecal contamination. Estimates from each study were combined under a random-effects meta-analysis framework. The study protocol was pre-registered with PROSPERO (CRD42018102114).

FINDINGS

From 72 eligible studies, we included IPD for 20 studies in the meta-analyses, totalling 54 225 diarrhoea or linear growth observations matched to faecal indicator bacteria concentrations in drinking water, and a further 35 010 observations with faecal contamination data for the other transmission pathways. Child diarrhoea was associated with 1-log₁₀ higher faecal indicator bacteria concentrations in drinking water (OR 1·09, 95% CI 1·04 to 1·13; p=0·0002, I²=34%, 95% CI 0 to 62) and on children's hands (1·11, 1·02 to 1·22; p=0·021, I²=0%, 0 to 71). Lower HAZ scores were associated with 1-log₁₀ higher median faecal indicator bacteria concentrations in drinking water (HAZ -0·04, 95% CI -0·06 to -0·01; p=0·0054; I²=19%, 95% CI 0 to 63) and on fomites (-0·06, -0·12 to 0·00; p=0·044, I²=57%, 0 to 90).

INTERPRETATION

Although summary measures from individual studies often report little or no effect of measured faecal contamination on child health, this multi-study IPD analysis indicates that household faecal indicator bacteria concentrations are associated with important adverse health outcomes in young children. Improved direct measures of exposure and enteric pathogens could help to better characterise the relationship and inform intervention design in future studies.

FUNDING

None.

Coliform bacteria and salt content as drinking water challenges at sand dams in Kenya

Sand dams can be an effective community-scale solution to increasing water supplies in some arid and semi-arid regions, but there are few studies that have investigated water quality at sand dams. This study investigated the levels of coliform bacteria and salt content as parameters of potential concern. Most water taken from sand dam sources had fecal coliforms present. Median fecal coliforms were in the range of 150-800 cfu/100 ml for unprotected sources (scoop holes, surface water or hand dug wells), levels which are considered high or very high health risk. Pump wells had less contamination, with fecal coliforms detected in one-third of samples in the dry season. Despite this contamination, user surveys indicated that 74% of communities generally view water as clean for drinking, and 72% reported that no or few people in their community treat their water. Salt content in the dry season was in the poor or unacceptable range (above 900 ppm as total dissolved solids) in 33% of water samples. Results suggest that fecal coliforms and salt content represent two types of challenges to water quality at sand dams: fecal coliforms are a health hazard, whereas high salt content potentially reduces the amount of usable water that is available.

Determinants of Sanitation and Hygiene Status Among Food Establishments in Addis Ababa, Ethiopia

INTRODUCTION

Despite advancements in food science and technology, foodborne disease remains one of the major public health problems. Poor sanitation and hygiene conditions of food establishments are the major causes for the occurrence of foodborne disease. Therefore, this study aimed to investigate core determinants of sanitation and hygiene status among food establishments.

METHODS

Institution-based cross-sectional study design was conducted in Addis Ababa city. A stratified random sampling technique was deployed to select 413 study participants. Data were collected through interview and using observational checklist. Sample size was determined by using a single population proportion formula. To analyze the data, binary logistic regression and multivariable logistic regression analysis was conducted. In all analysis, P-value less than .05 were considered statistically significant.

RESULTS

The study revealed that 57.4% of the food establishments were under poor sanitation status. In the multivariable analysis, presence of trained managers on hygiene and sanitation (adjusted odds ratio [AOR] = 6.10 with 95% confidence interval [CI]: 2.41-15.45), presence of renewed licenses (AOR = 3.07 with 95% CI: 1.18-7.99), absence of bureaucratic function to obtain permission to renew the food establishment buildings (AOR = 2.43 with 95% CI: 1.25-4.70), and presence of at least 10-m distance between toilet and kitchen (AOR = 9.19, at 95% CI: 5.63-15.02) were associated significantly with sanitation and hygiene status.

CONCLUSIONS

Above average of the food establishments were found to be in poor sanitation and hygiene state. Many core determinant factors that influence sanitation and hygienic status of food establishments were identified. The researchers suggest that formal training on sanitation and hygiene for managers of food establishments should be provided to reduce the occurrence of foodborne diseases. Moreover, strong food and water safety policy and strategy should be promulgated to improve sanitation and hygiene status of food establishments.

A Syringe-Based Biosensor to Rapidly Detect Low Levels of Escherichia Coli (ECOR13) in Drinking Water Using Engineered Bacteriophages

A sanitized drinking water supply is an unconditional requirement for public health and the overall prosperity of humanity. Potential microbial and chemical contaminants of drinking water have been identified by a joint effort between the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF), who together establish guidelines that define, in part, that the presence of Escherichia coli (E. coli) in drinking water is an indication of inadequate sanitation and a significant health risk. As E. coli is a nearly ubiquitous resident of mammalian gastrointestinal tracts, no detectable counts in 100 mL of drinking water is the standard used worldwide as an indicator of sanitation. The currently accepted EPA method relies on filtration, followed by growth on selective media, and requires 24-48 h from sample to results. In response, we developed a rapid bacteriophage-based detection assay with detection limit capabilities comparable to traditional methods in less than a quarter of the time. We coupled membrane filtration with selective enrichment using genetically engineered bacteriophages to identify less than 20 colony forming units (CFU) E. coli in 100 mL drinking water within 5 h. The combination of membrane filtration with phage infection produced a novel assay that demonstrated a rapid, selective, and sensitive detection of an indicator organism in large volumes of drinking water as recommended by the leading world regulatory authorities.

Diarrheal disease and associated behavioural factors among food handlers in Addis Ababa, Ethiopia

Introduction: Diarrheal diseases are threat everywhere, but its frequency and impact are more severe in developing countries. Diarrhea occurs world-wide and causes 4% of all deaths and 5% of health loss to disability. In 2016, it was the eighth leading cause of mortality. Moreover, data from the World Health Organization indicated that diarrheal diseases are causes for an estimated 2 million deaths annually. Therefore, this study aimed to assess diarrheal diseases and associated behavioural factors. Method: An institution based cross-sectional study was conducted. A stratified random sampling method was employed to select 1050 study participants. Participants were interviewed using structured questionnaire. To analysis the data, binary logistic regression and multivariable logistic regression analysis was conducted. Results: The two weeks prevalence of diarrhea was found to be 3.4%. Further, 1.6%, 10.5%, 10.7% and 9% of the food handlers had acute watery diarrhea, cough, an infection of runny nose and incidence of any fever respectively. Regular hand washing after toilet (AOR = 0.13 with 95% CI: 0.024, 0.72), using toilet while wearing protective clothes/gown (AOR = 5.39 with 95% CI; 1.59, 18.32), habit of eating raw beef and raw vegetables (AOR = 6.27 with 95% CI: 1.89–20.78), type of toilet (AOR = 4.07 with 95% CI: 0.29–6.67 were associated significantly with diarrhea. Conclusion: This assessment proved to be an essential activity for reduction of community diarrheal diseases, as a significant number of food handlers had diarrhea. Good sanitation, hygiene practice and a healthy lifestyle behavior can prevent diarrhea. A strong political commitment with appropriate budgetary allocation is essential for the control of diarrheal diseases.

Water, sanitation, and hygiene risk factors of acute diarrhea among children under five years in the Gaza Strip

This cross-sectional community household-based study aims to evaluate the water, sanitation, and hygiene facilities in the Gaza Strip and to investigate their associations with the occurrence of acute diarrhea among children under five years. A survey using a structured questionnaire was conducted on 1,857 households with an child under five years from August 2017 to June 2018. About 69.7% of heads of households reported a diarrheal episode among their children during the two months preceding the survey. Multivariable logistic regression showed that sewage water observed around the households was associated with an increased risk of acute diarrhea (AOR = 2.45; P &lt; 0.001; 95% CI: 1.83–3.27). Nevertheless, the allocation of a special water tank for desalinated drinking water at home (AOR = 0.3; P = 0.02; 95% CI: 0.1–0.8), the connection of households to a closed sewerage system (AOR = 0.56; P &lt; 0.001; 95% CI: 0.43–0.73), and handwashing practices before and after eating (AOR = 0.42; P = 0.003; 95% CI: 0.24–0.74 and AOR = 0.50; P = 0.03; 95% CI: 0.26–0.94, respectively), as well as using desalinated water sources for drinking purposes, were inversely associated with the incidence of acute diarrhea among children under five. Further improvements in the existing sewerage system and the intensification of sanitation and hygiene promotion programs at the household levels may reduce the risk of acute diarrhea among children under five years in the Gaza Strip.

Effects of a large-scale distribution of water filters and natural draft rocket-style cookstoves on diarrhea and acute respiratory infection: A cluster-randomized controlled trial in Western Province, Rwanda

BACKGROUND

Unsafe drinking water and household air pollution (HAP) are major causes of morbidity and mortality among children under 5 in low and middle-income countries. Household water filters and higher-efficiency biomass-burning cookstoves have been widely promoted to improve water quality and reduce fuel use, but there is limited evidence of their health effects when delivered programmatically at scale.

METHODS AND FINDINGS

In a large-scale program in Western Province, Rwanda, water filters and portable biomass-burning natural draft rocket-style cookstoves were distributed between September and December 2014 and promoted to over 101,000 households in the poorest economic quartile in 72 (of 96) randomly selected sectors in Western Province. To assess the effects of the intervention, between August and December, 2014, we enrolled 1,582 households that included a child under 4 years from 174 randomly selected village-sized clusters, half from intervention sectors and half from nonintervention sectors. At baseline, 76% of households relied primarily on an improved source for drinking water (piped, borehole, protected spring/well, or rainwater) and over 99% cooked primarily on traditional biomass-burning stoves. We conducted follow-up at 3 time-points between February 2015 and March 2016 to assess reported diarrhea and acute respiratory infections (ARIs) among children <5 years in the preceding 7 days (primary outcomes) and patterns of intervention use, drinking water quality, and air quality. The intervention reduced the prevalence of reported child diarrhea by 29% (prevalence ratio [PR] 0.71, 95% confidence interval [CI] 0.59-0.87, p = 0.001) and reported child ARI by 25% (PR 0.75, 95% CI 0.60-0.93, p = 0.009). Overall, more than 62% of households were observed to have water in their filters at follow-up, while 65% reported using the intervention stove every day, and 55% reported using it primarily outdoors. Use of both the intervention filter and intervention stove decreased throughout follow-up, while reported traditional stove use increased. The intervention reduced the prevalence of households with detectable fecal contamination in drinking water samples by 38% (PR 0.62, 95% CI 0.57-0.68, p < 0.0001) but had no significant impact on 48-hour personal exposure to log-transformed fine particulate matter (PM2.5) concentrations among cooks (β = -0.089, p = 0.486) or children (β = -0.228, p = 0.127). The main limitations of this trial include the unblinded nature of the intervention, limited PM2.5 exposure measurement, and a reliance on reported intervention use and reported health outcomes.

CONCLUSIONS

Our findings indicate that the intervention improved household drinking water quality and reduced caregiver-reported diarrhea among children <5 years. It also reduced caregiver-reported ARI despite no evidence of improved air quality. Further research is necessary to ascertain longer-term intervention use and benefits and to explore the potential synergistic effects between diarrhea and ARI.

TRIAL REGISTRATION

Clinical Trials.gov NCT02239250.

Investigation of the water quality of daily used surface-sources for drinking and irrigation by the population of Segou in the center of Mali

This study evaluates the quality and pollution status of source surface waters in Segou, Mali. The nature, sources, and extent of pollution of Comatex Stream, Cerfitex Pond, and Sonikoura River were studied for a period of twelve months (July 2016-June 2017). Analysis included 209 water samples collected from eleven different locations in the study area. Laboratory and field analysis were realized using the standard methods and concerned eleven parameters including four physicals, six chemicals and one bacteriological. Also, organoleptic parameters were observed. Most of the average values of parameters addressing the quality of water were significantly higher (P < 0.05) in both the stream and river compared to the pond. Fecal coliform counts (FCC) were not in significant correlation with the temperature; pH and turbidity; but had a significant and positive correlation (P < 0.05) with conductivity: total dissolved solids (TDS); total suspended solids (TSS); Cl^-; PO₄ ^-P; NO₃ ^-N and 5-day biochemical oxygen demand (BOD₅). Analysis of samples revealed a level of FCC that is above the permissible limit for both drinking water and of fresh vegetable irrigation water. In all, there is a pressing need to inform the public about the state of water bodies and the application of relevant laws regarding the proper treatment of sewage before it is discharged into surface water.

Identifying different types of flood-sensitive diarrheal diseases from 2006 to 2010 in Guangxi, China

Floods may influence different types of diarrheal diseases and epidemiological studies of pathogen-specific diarrhea due to floods in China are still needed. In addition, few studies have been conducted to quantify the lag and cumulative risk of diarrheal disease due to floods in Guangxi, China. Our study aimed to identify different types of diarrheal diseases that were sensitive to floods and to quantify their lag and cumulative impact. A matched analysis based on time series data of floods and infectious disease from 2006 to 2010 was conducted in Guangxi, China. Each flood day was treated as an independent unit in our study. A simplified assumption that each day of the flood confers the same risk was adopted before analysis. Each flood day was matched to a non-flood day by city and time. Log-linear mixed-effects regression models were used to quantify the association between different types of diarrheal diseases and floods. Lag and cumulative effects were also calculated to get delayed and overall effects. A total of 45,131 diarrhea cases were notified in the study area over the study period. After controlling for the long-term trend, seasonality, and meteorological factors, floods caused a significantly increased risk of total diarrheal diseases. The RR was highest at lag 2 days (RR=1.24, 95% CI: 1.11-1.40). Floods caused a significantly increased risk in bacillary dysentery and in other infectious diarrhea, but not in typhoid fever and paratyphoid fever. Floods were significantly associated with total diarrheal diseases and other infectious diarrhea for both cumulative lag 0-7 and 0-14 days. Our study provides strong evidence of a positive association between floods and diarrheal diseases including bacillary dysentery and other infectious diarrhea in study area. Public health interventions should be taken to prevent a potential risk of these flood-sensitive diarrheal diseases according to the different lag period after floods.

Association between floods and infectious diarrhea and their effect modifiers in Hunan province, China: A two-stage model

BACKGROUND

Understanding the potential links between floods and infectious diarrhea is important under the context of climate change. However, little is known about the risk of infectious diarrhea after floods and what factors could modify these effects in China.

OBJECTIVES

This study aims to quantitatively examine the relationship between floods and infectious diarrhea and their effect modifiers.

METHODS

Weekly number of infectious diarrhea cases from 2004 to 2011 during flood season in Hunan province were supplied by the National Notifiable Disease Surveillance System. Flood and meteorological data over the same period were obtained. A two-stage model was used to estimate a provincial average association and their effect modifiers between floods and infectious diarrhea, accounting for other confounders.

RESULTS

A total of 134,571 cases of infectious diarrhea were notified from 2004 to 2011. After controlling for seasonality, long-term trends, and meteorological factors, floods were significantly associated with infectious diarrhea in the provincial level with a cumulative RR of 1.22 (95% CI: 1.05, 1.43) with a lagged effect of 0-1 week. Geographic locations and economic levels were identified as effect modifiers, with a higher impact of floods on infectious diarrhea in the western and regions with a low economic level of Hunan.

CONCLUSIONS

Our study provides strong evidence of a positive association between floods and infectious diarrhea in the study area. Local control strategies for public health should be taken in time to prevent and reduce the risk of infectious diarrhea after floods, especially for the vulnerable regions identified.

The Effectiveness of Sanitary Inspections as a Risk Assessment Tool for Thermotolerant Coliform Bacteria Contamination of Rural Drinking Water: A Review of Data from West Bengal, India

AbstractThe use of sanitary inspections combined with periodic water quality testing has been recommended in some cases as screening tools for fecal contamination. We conducted sanitary inspections and tested for thermotolerant coliforms (TTCs), a fecal indicator bacteria, among 7,317 unique water sources in West Bengal, India. Our results indicate that the sanitary inspection score has poor ability to identify TTC-contaminated sources. Among deep and shallow hand pumps, the area under curve (AUC) for prediction of TTC > 0 was 0.58 (95% confidence interval [CI] = 0.53-0.61) and 0.58 (95% CI = 0.54-0.62), respectively, indicating that the sanitary inspection score was only marginally better than chance in discriminating between contaminated and uncontaminated sources of this type. A slightly higher AUC value of 0.64 (95% CI=0.57-0.71) was observed when the sanitary inspection score was used for prediction of TTC > 0 among the gravity-fed piped sources. Among unprotected springs (AUC = 0.48, 95% CI = 0.38-0.55) and unprotected dug wells (AUC = 0.41, 95% CI = 0.20-0.66), the sanitary inspection score performed more poorly than chance in discriminating between sites with TTC < 1 and TTC > 0. Aggregating over all source types, the sensitivity (true positive rate) of a high/very high sanitary inspection score for TTC contamination (TTC > 1 CFU/100 mL) was 29.4% and the specificity (true negative rate) was 77.9%, resulting in substantial misclassification of the sites when using the established risk categories. These findings suggest that sanitary surveys are inappropriate screening tools for identifying TTC contamination at water points.

Faecal contamination of household drinking water in Rwanda: A national cross-sectional study

Unsafe drinking water is a leading cause of morbidity and mortality, especially among young children in low-income settings. We conducted a national survey in Rwanda to determine the level of faecal contamination of household drinking water and risk factors associated therewith. Drinking water samples were collected from a nationally representative sample of 870 households and assessed for thermotolerant coliforms (TTC), a World Health Organization (WHO)-approved indicator of faecal contamination. Potential household and community-level determinants of household drinking water quality derived from household surveys, the 2012 Rwanda Population and Housing Census, and a precipitation dataset were assessed using multivariate logistic regression. Widespread faecal contamination was present, and only 24.9% (95% CI 20.9-29.4%, n=217) of household samples met WHO Guidelines of having no detectable TTC contamination, while 42.5% (95% CI 38.0-47.1%, n=361) of samples had >100TTC/100mL and considered high risk. Sub-national differences were observed, with poorer water quality in rural areas and Eastern province. In multivariate analyses, there was evidence for an association between detectable contamination and increased open waste disposal in a sector, lower elevation, and water sources other than piped to household or rainwater/bottled. Risk factors for intermediate/high risk contamination (>10TTC/100mL) included low population density, increased open waste disposal, lower elevation, water sources other than piped to household or rainwater/bottled, and occurrence of an extreme rain event the previous day. Modelling suggests non-household-based risk factors are determinants of water quality in this setting, and these results suggest a substantial proportion of Rwanda's population are exposed to faecal contamination through drinking water.