Prevalence and determinants of hypertension among older adults: A comparative analysis of the 6th and 8th national health surveys of Bangladesh

BACKGROUND

Hypertension is a major public health concern in low-and middle-income countries. A nationwide Health, Population, and Nutrition Sector Development Program in Bangladesh has been shown to be effective in resource-poor settings. This article aims to investigate whether the prevalence and determinants of adult hypertension changed from 2011 to 2018.

METHODS

The determinants of adult hypertension were assessed in 2011 and 2018 data of Bangladesh Demographic and Health surveys. These two surveys included both men and women over the age of 34 years and measured their blood pressure, weight, height, and other covariates. For both surveys, we estimated the age-standard prevalence of hypertension and relative, attributable and mediated risk of determinants of hypertension using hierarchical mixed-effects sequential Poisson regression models.

RESULTS

The prevalence of adult hypertension increased by 10.9% from 29.5% in 2011 to 40.4% in 2018. The nationwide awareness program on the Health, Population and Nutrition Sector changed the risks associated with hypertension determinants over the years. During 2011, Socio-economic status (SES) was a major distal determinant of adult hypertension, explaining 21% of population-attributable risk (ART). However, other factors accounted for 90% of risk, mainly by excessive body weight (51%) and awareness of hypertension (39%). In contrast, SES only explained 16% of ART risk, with 97% of the risk mediated by excessive body weight (55%) and awareness of hypertension (41%).

CONCLUSION

The study results highlight that hypertension among older adult was significantly increased over the six-year period. Specially, the socio-economic status, awareness of hypertension and excessive body weight were the significant determinants. Being awareness of hypertension and excessive body weight changed the causal pathways of socio-economic status. The results also highlight the value of studying the effect of non-communicable disease awareness programs to enhance our comprehension of factors influencing health.

Risk Factors Associated with Diarrheal Episodes in an Agricultural Community in Nam Dinh Province, Vietnam: A Prospective Cohort Study

In Vietnam, data on the risk factors for diarrhea at the community level remain sparse. This study aimed to provide an overview of diarrheal diseases in an agricultural community in Vietnam, targeting all age groups. Specifically, we investigated the incidence of diarrheal disease at the community level and described the potential risk factors associated with diarrheal diseases. In this prospective cohort study, a total of 1508 residents were enrolled during the 54-week study period in northern Vietnam. The observed diarrheal incidence per person-year was 0.51 episodes. For children aged <5 years, the incidence per person-year was 0.81 episodes. Unexpectedly, the frequency of diarrhea was significantly higher among participants who used tap water for drinking than among participants who used rainwater. Participants who used a flush toilet had less frequent diarrhea than those who used a pit latrine. The potential risk factors for diarrhea included the source of water used in daily life, drinking water, and type of toilet. However, the direct reason for the association between potential risk factors and diarrhea was not clear. The infection routes of diarrheal pathogens in the environment remain to be investigated at this study site.

Interventions promoting uptake of water, sanitation and hygiene (WASH) technologies in low- and middle-income countries: An evidence and gap map of effectiveness studies

Background

Lack of access to and use of water, sanitation and hygiene (WASH) cause 1.6 million deaths every year, of which 1.2 million are due to gastrointestinal illnesses like diarrhoea and acute respiratory infections like pneumonia. Poor WASH access and use also diminish nutrition and educational attainment, and cause danger and stress for vulnerable populations, especially for women and girls. The hardest hit regions are sub-Saharan Africa and South Asia. Sustainable Development Goal (SDG) 6 calls for the end of open defecation, and universal access to safely managed water and sanitation facilities, and basic hand hygiene, by 2030. WASH access and use also underpin progress in other areas such as SDG1 poverty targets, SDG3 health and SDG4 education targets. Meeting the SDG equity agenda to "leave none behind" will require WASH providers prioritise the hardest to reach including those living remotely and people who are disadvantaged.

Objectives

Decision makers need access to high-quality evidence on what works in WASH promotion in different contexts, and for different groups of people, to reach the most disadvantaged populations and thereby achieve universal targets. The WASH evidence map is envisioned as a tool for commissioners and researchers to identify existing studies to fill synthesis gaps, as well as helping to prioritise new studies where there are gaps in knowledge. It also supports policymakers and practitioners to navigate the evidence base, including presenting critically appraised findings from existing systematic reviews.

Methods

This evidence map presents impact evaluations and systematic reviews from the WASH sector, organised according to the types of intervention mechanisms, WASH technologies promoted, and outcomes measured. It is based on a framework of intervention mechanisms (e.g., behaviour change triggering or microloans) and outcomes along the causal pathway, specifically behavioural outcomes (e.g., handwashing and food hygiene practices), ill-health outcomes (e.g., diarrhoeal morbidity and mortality), nutrition and socioeconomic outcomes (e.g., school absenteeism and household income). The map also provides filters to examine the evidence for a particular WASH technology (e.g., latrines), place of use (e.g., home, school or health facility), location (e.g., global region, country, rural and urban) and group (e.g., people living with disability). Systematic searches for published and unpublished literature and trial registries were conducted of studies in low- and middle-income countries (LMICs). Searches were conducted in March 2018, and searches for completed trials were done in May 2020. Coding of information for the map was done by two authors working independently. Impact evaluations were critically appraised according to methods of conduct and reporting. Systematic reviews were critically appraised using a new approach to assess theory-based, mixed-methods evidence synthesis.

Results

There has been an enormous growth in impact evaluations and systematic reviews of WASH interventions since the International Year of Sanitation, 2008. There are now at least 367 completed or ongoing rigorous impact evaluations in LMICs, nearly three-quarters of which have been conducted since 2008, plus 43 systematic reviews. Studies have been done in 83 LMICs, with a high concentration in Bangladesh, India, and Kenya. WASH sector programming has increasingly shifted in focus from what technology to supply (e.g., a handwashing station or child's potty), to the best way in which to do so to promote demand. Research also covers a broader set of intervention mechanisms. For example, there has been increased interest in behaviour change communication using psychosocial "triggering", such as social marketing and community-led total sanitation. These studies report primarily on behavioural outcomes. With the advent of large-scale funding, in particular by the Bill & Melinda Gates Foundation, there has been a substantial increase in the number of studies on sanitation technologies, particularly latrines. Sustaining behaviour is fundamental for sustaining health and other quality of life improvements. However, few studies have been done of intervention mechanisms for, or measuring outcomes on sustained adoption of latrines to stop open defaecation. There has also been some increase in the number of studies looking at outcomes and interventions that disproportionately affect women and girls, who quite literally carry most of the burden of poor water and sanitation access. However, most studies do not report sex disaggregated outcomes, let alone integrate gender analysis into their framework. Other vulnerable populations are even less addressed; no studies eligible for inclusion in the map were done of interventions targeting, or reporting on outcomes for, people living with disabilities. We were only able to find a single controlled evaluation of WASH interventions in a health care facility, in spite of the importance of WASH in health facilities in global policy debates. The quality of impact evaluations has improved, such as the use of controlled designs as standard, attention to addressing reporting biases, and adequate cluster sample size. However, there remain important concerns about quality of reporting. The quality and usefulness of systematic reviews for policy is also improving, which draw clearer distinctions between intervention mechanisms and synthesise the evidence on outcomes along the causal pathway. Adopting mixed-methods approaches also provides information for programmes on barriers and enablers affecting implementation.

Conclusion

Ensuring everyone has access to appropriate water, sanitation, and hygiene facilities is one of the most fundamental of challenges for poverty elimination. Researchers and funders need to consider carefully where there is the need for new primary evidence, and new syntheses of that evidence. This study suggests the following priority areas:Impact evaluations incorporating understudied outcomes, such as sustainability and slippage, of WASH provision in understudied places of use, such as health care facilities, and of interventions targeting, or presenting disaggregated data for, vulnerable populations, particularly over the life-course and for people living with a disability;Improved reporting in impact evaluations, including presentation of participant flow diagrams; andSynthesis studies and updates in areas with sufficient existing and planned impact evaluations, such as for diarrhoea mortality, ARIs, WASH in schools and decentralisation. These studies will preferably be conducted as mixed-methods systematic reviews that are able to answer questions about programme targeting, implementation, effectiveness and cost-effectiveness, and compare alternative intervention mechanisms to achieve and sustain outcomes in particular contexts, preferably using network meta-analysis.

Maternal Characteristics Mediating the Impact of Household Poverty on the Nutritional Status of Children Under 5 Years of Age in Bangladesh

OBJECTIVES

We explored the maternal characteristics that mediate the effect of household poverty on childhood undernutrition.

METHODS

We used the population-based Bangladesh Demographic Health Survey data from 2014 for demographic characteristics, child and maternal factors.

RESULTS

Of the 7173 under-5 children, 3456 (48.2%) had undernutrition. The prevalence of undernutrition was less common in wealthy households (poorest vs richest: adjusted prevalence ratio [aPR] = 1.37), mothers having history of antenatal care (ANC) visits (no visit vs ≥ 4 visits: aPR = 1.22), maternal higher education (no education vs higher education: aPR = 1.54), and mothers with good nutritional status (underweight vs healthy: aPR = 1.13). The risk of undernutrition (37.1%) was attributed to household wealth, mediated 55% by maternal factors; of which 20% by maternal education, 21% by ANC visits, and 14% by maternal nutritional status.

CONCLUSIONS

Our study findings outlined higher maternal education, ≥ 4 ANC visits and good maternal nutritional status in mediating the impact of household wealth on childhood nutrition.

Market integration and soil-transmitted helminth infection among the Shuar of Amazonian Ecuador

BACKGROUND

Soil-transmitted helminth (STH) infections have many negative health outcomes (e.g., diarrhea, nutritional deficiencies) that can also exacerbate poverty. These infections are generally highest among low-income populations, many of which are also undergoing market integration (MI; increased participation in a market-based economy). Yet the direct impact of MI-related social and environmental changes on STH infection patterns is poorly understood, making it unclear which lifestyle factors should be targeted to better control disease spread. This cross-sectional study examines if household infrastructure associated with greater MI is associated with lower STH burdens among Indigenous Ecuadorian Shuar.

METHODS

Kato-Katz fecal smears were used to determine STH infection status and intensity (n = 620 participants; 308 females, 312 males, aged 6 months-86 years); Ascaris lumbricoides (ascarid) and Trichuris trichiura (whipworm) were the primary infection types detected. Structured interviews assessing lifestyle patterns (e.g., measures of household infrastructure) measured participant MI. Multilevel regression analyses and zero-inflated negative binomial regression models tested associations between MI measures and STH infection status or intensity, controlling for individual and community characteristics.

RESULTS

Participants residing in more market-integrated households exhibited lower infection rates and intensities than those in less market integrated households. Parasite infection status and T. trichiura infection intensity were lower among participants living in houses with wood floors than those with dirt floors, while individuals using well or piped water from a spring exhibited lower A. lumbricoides infection intensities compared to those using river or stream water. Unexpectedly, latrine type was not significantly related to STH infection status or intensity. These results suggest that sources of exposure differ between the two helminth species.

CONCLUSIONS

This study documents associations between household measures and STH infection among an Indigenous population undergoing rapid MI. These findings can help healthcare programs better target interventions and reduce STH exposure among at-risk populations.

Changing of risk factors related to diarrhoea among children aged under 5 within ten years in Turkey

OBJECTIVES

The aim of this study is to determine the risk factors of childhood diarrhoea in Turkey throughout Turkey Demographic and Health Survey (DHS) 1998 and 2008 data.

METHODS

This study is a further analysis of the database of children under 5 years of age from the Turkey Demographic and Health Survey. Binomial logistic regression and Chi square analysis were used by weighted data of Turkey Demographic and Health Surveys.

RESULTS

In 1998 DHS there were 3,459 and in 2008 DHS 3,463 children under 5 years of age. Diarrhoea prevalence was 30.1% and 18.3%, respectively. Multivariate analysis revealed that household wealth status index, region, mother's education, mother's age (15-19 age), age (under 2 years of age), and sex (male) of the child were the risk factors for 1998 DHS. In 2008 significant risk factors were geographic region, education of the mother and father, breastfeeding status of the child (still being breastfed), mother's age (20-29 age group), and age of child (under 2 years of age).

CONCLUSIONS

As a result, patterns of the risk factors of diarrhoea has changed from 1998 to 2008 DHS in Turkey. However, impact of factors related with socioeconomic environment such as region and mother's education persisted.

Urban sanitation coverage and environmental fecal contamination: Links between the household and public environments of Accra, Ghana

Exposure to fecal contamination in public areas, especially in dense, urban environments, may significantly contribute to enteric infection risk. This study examined associations between sanitation and fecal contamination in public environments in four low-income neighborhoods in Accra, Ghana. Soil (n = 72) and open drain (n = 90) samples were tested for E. coli, adenovirus, and norovirus. Sanitation facilities in surveyed households (n = 793) were categorized by onsite fecal sludge containment ("contained" vs. "uncontained") using previous Joint Monitoring Program infrastructure guidelines. Most sanitation facilities were shared by multiple households. Associations between spatial clustering of household sanitation coverage and fecal contamination were examined, controlling for neighborhood and population density (measured as enumeration areas in the 2010 census and spatially matched to sample locations). E. coli concentrations in drains within 50m of clusters of contained household sanitation were more than 3 log-units lower than those outside of clusters. Further, although results were not always statistically significant, E. coli concentrations in drains showed consistent trends with household sanitation coverage clusters: concentrations were lower in or near clusters of high coverage of household sanitation facilities-especially contained facilities-and vice versa. Virus detection in drains and E. coli concentrations in soil were not significantly associated with clustering of any type of household sanitation and did not exhibit consistent trends. Population density alone was not significantly associated with any of the fecal contamination outcomes by itself and was a significant, yet inconsistent, effect modifier of the association between sanitation clusters and E. coli concentrations. These findings suggest clustering of contained household sanitation, even when shared, may be associated with lower levels of fecal contamination within drains in the immediate public domain. Further research is needed to better quantify these relationships and examine impacts on health.

The associations between water and sanitation and hookworm infection using cross-sectional data from Togo's national deworming program

Background

Sustainable control of soil-transmitted helminths requires a combination of chemotherapy treatment and environmental interventions, including access to safe drinking water, sufficient water for hygiene, use of clean sanitation facilities, and handwashing (WASH). We quantified associations between home-, school-, and community-level WASH characteristics and hookworm infection—both prevalence and eggs per gram of stool (intensity)—among Togolese school children in the context of community-based chemotherapy treatments administered in the country from 2010 through 2014.

Methodology/Principal findings

We analyzed data from two surveys conducted by the Togo Ministry of Health: a school-based survey of students aged 6–9 years across Togo conducted in 2009 and a follow-up survey in 2015, after four to five years of preventive chemotherapy. Data were available for 16,473 students attending 1,129 schools in 2009 and for 16,890 students from 1,126 schools in 2015. Between surveys, children in study schools received 0 to 8 rounds of deworming chemotherapy treatments. Few WASH conditions (only unimproved drinking water) were found to be significantly associated with the presence or absence of hookworms in an individual; however, quantitative eggs per gram of feces was associated with availability of unimproved drinking water, availability of improved drinking water either on or off school grounds, having a handwashing station with water available, and access to a sex-separate non-private or private latrine. The association between school WASH conditions and hookworm infection or burden often depended on the 2009 prevalence of infection, as more WASH characteristics were found to be significant predictors of infection among schools with high underlying endemicity of hookworm.

Conclusions/Significance

Our findings emphasize the complex and often inconsistent or unpredictable relationship between WASH and hookworm. Specifically, we found that while preventive chemotherapy appeared to dramatically reduce hookworm infection, WASH was associated with infection intensity.

Preventive chemotherapy plays a critical role in breaking transmission of soil-transmitted helminths but it is likely that sustainable control of soil-transmitted helminths will require environmental improvements such as access to water for hygiene and hygienic sanitation, access to and use of a clean toilet facility, and handwashing with soap at key times (WASH). Here, we report on school-, home- and community-level WASH and the relationship of these characteristics with the prevalence and intensity of hookworm infection, one of the most prevalent soil-transmitted helminths, observed in the context of preventive chemotherapy among Togolese school children. In this large, country-wide assessment, few WASH conditions were found to be significant predictors of the presence or absence of hookworms in an individual, however, intensity of infection was associated with several WASH characteristics. Our analysis emphasizes the complex and often unpredictable role of WASH characteristics on hookworm, particularly relevant for Togolese and other international policy makers aiming to understand the interaction between WASH, preventive chemotherapy and hookworm. Further research taking into account not only WASH conditions but also use of WASH resources and practices would further strengthen our understanding of the interaction between WASH and deworming treatment as effective hookworm control strategies.

Migration, health, and socioenvironmental safety net among children of Dhaka, Bangladesh

This study quantifies the diarrhea burden among migrant children under age 5 (who have migrated due to environmental degradation) in Dhaka. We used a multifactor socioepidemiological as well as environmental approach with pretested questionnaires and observations. It was found that 52% of the children were affected by diarrhea. Disability-adjusted life years (DALYs) lost was reduced manifold with the increase of mothers' behavioral determinants. Health losses were 1,718 fold with significant coefficient (β) in the migrant group. DALYs lost were significantly associated with socioenvironmental factors such as mother's illiteracy (β = .18; p < .001), no hand wash before eating (β = .08; p = .004), and no hand wash after defecation (β = .10; p < .001). This puts emphasis clearly on the awareness at household level, especially of mothers and children under age 5 in Dhaka, Bangladesh, in formulating migration-related policies.

Multipathway Quantitative Assessment of Exposure to Fecal Contamination for Young Children in Low-Income Urban Environments in Accra, Ghana: The SaniPath Analytical Approach

Lack of adequate sanitation results in fecal contamination of the environment and poses a risk of disease transmission via multiple exposure pathways. To better understand how eight different sources contribute to overall exposure to fecal contamination, we quantified exposure through multiple pathways for children under 5 years old in four high-density, low-income, urban neighborhoods in Accra, Ghana. We collected more than 500 hours of structured observation of behaviors of 156 children, 800 household surveys, and 1,855 environmental samples. Data were analyzed using Bayesian models, estimating the environmental and behavioral factors associated with exposure to fecal contamination. These estimates were applied in exposure models simulating sequences of behaviors and transfers of fecal indicators. This approach allows us to identify the contribution of any sources of fecal contamination in the environment to child exposure and use dynamic fecal microbe transfer networks to track fecal indicators from the environment to oral ingestion. The contributions of different sources to exposure were categorized into four types (high/low by dose and frequency), as a basis for ranking pathways by the potential to reduce exposure. Although we observed variation in estimated exposure (108-1016 CFU/day for Escherichia coli) between different age groups and neighborhoods, the greatest contribution was consistently from food (contributing > 99.9% to total exposure). Hands played a pivotal role in fecal microbe transfer, linking environmental sources to oral ingestion. The fecal microbe transfer network constructed here provides a systematic approach to study the complex interaction between contaminated environment and human behavior on exposure to fecal contamination.

Effects of improved sanitation on diarrheal reduction for children under five in Idiofa, DR Congo: a cluster randomized trial

Background

The lack of safe water and sanitation contributes to the rampancy of diarrhea in many developing countries.

Methods

This study describes the design of a cluster-randomized trial in Idiofa, the Democratic Republic of the Congo, seeking evidence of the impact of improved sanitation on diarrhea for children under four. Of the 276 quartiers, 18 quartiers were randomly allocated to the intervention or control arm. Seven hundred and-twenty households were sampled and the youngest under-four child in each household was registered for this study. The primary endpoint of the study is diarrheal incidence, prevalence and duration in children under five.

Discussion

Material subsidies will be provided only to the households who complete pit digging plus superstructure and roof construction, regardless of their income level. This study employs a Sanitation Calendar so that the mother of each household can record the diarrheal episodes of her under-four child on a daily basis. The diary enables examination of the effect of the sanitation intervention on diarrhea duration and also resolves the limitation of the small number of clusters in the trial.

In addition, the project will be monitored through the ‘Sanitation Map’, on which all households in the study area, including both the control and intervention arms, are registered. To avoid information bias or courtesy bias, photos will be taken of the latrine during the household visit, and a supervisor will determine well-equipped latrine uptake based on the photos. This reduces the possibility of recall bias and under- or over-estimation of diarrhea, which was the main limitation of previous studies.

Trial registration

The study was approved by the Institutional Review Board of the School of Public Health, Kinshasa University (ESP/CE/040/15; April 13, 2015) and registered as an International Standard Randomized Controlled Trial (ISRCTN: 10,419,317) on March 13, 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0351-x) contains supplementary material, which is available to authorized users.

Spatial and temporal patterns of diarrhoea in Bhutan 2003-2013

Background

To describe spatiotemporal patterns of diarrhoea in Bhutan, and quantify the association between climatic factors and the distribution and dynamics of the disease.

Methods

Nationwide data on diarrhoea were obtained for 2003 to 2013 from the Health Information and Management System (HIMS), Ministry of Health, Bhutan. Climatic variables were obtained from the Department of Hydro Met Services, Ministry of Economic Affairs, Bhutan. Seasonal trend decomposition was used to examine secular trends and seasonal patterns of diarrhoea. A Bayesian conditional autoregressive (CAR) model was used to quantify the relationship between monthly diarrhoea, maximum temperature, rainfall, age and gender.

Results

The monthly average diarrhoea incidence was highly seasonal. Diarrhoea incidence increased by 0.6% (95% CrI: 0.5–0.6%) for every degree increase in maximum temperature; and 5% (95 Cr I: 4.9–5.1%) for a 1 mm increase in rainfall. Children aged <5 years were found to be 74.2% (95% CrI: 74.1–74.4) more likely to experience diarrhoea than children and adults aged ≥5 years and females were 4.9% (95% CrI: 4.4–5.3%) less likely to suffer from diarrhoea as compared to males. Significant residual spatial clustering was found after accounting for climate and demographic variables.

Conclusions

Diarrhoea incidence was highly seasonal, with positive associations with maximum temperature and rainfall and negative associations with age and being female. This calls for public health actions to reduce future risks of climate change with great consideration of local climatic conditions. In addition, protection of <5 years children should be prioritize through provision of rotavirus vaccination, safe and clean drinking water, and proper latrines.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2611-6) contains supplementary material, which is available to authorized users.

Household sanitation is associated with lower risk of bacterial and protozoal enteric infections, but not viral infections and diarrhoea, in a cohort study in a low-income urban neighbourhood in Vellore, India

Objective

This study examined associations between household sanitation and enteric infection – including diarrhoeal‐specific outcomes – in children 0–2 years of age in a low‐income, dense urban neighbourhood.

Methods

As part of the MAL‐ED study, 230 children in a low‐income, urban, Indian neighbourhood provided stool specimens at 14–17 scheduled time points and during diarrhoeal episodes in the first 2 years of life that were analysed for bacterial, parasitic (protozoa and helminths) and viral pathogens. From interviews with caregivers in 100 households, the relationship between the presence (and discharge) of household sanitation facilities and any, pathogen‐specific, and diarrhoea‐specific enteric infection was tested through mixed‐effects Poisson regression models.

Results

Few study households (33%) reported having toilets, most of which (82%) discharged into open drains. Controlling for season and household socio‐economic status, the presence of a household toilet was associated with lower risks of enteric infection (RR: 0.91, 95% CI: 0.79–1.06), bacterial infection (RR: 0.87, 95% CI: 0.75–1.02) and protozoal infection (RR: 0.64, 95% CI: 0.39–1.04), although not statistically significant, but had no association with diarrhoea (RR: 1.00, 95% CI: 0.68–1.45) or viral infections (RR: 1.12, 95% CI: 0.79–1.60). Models also suggested that the relationship between household toilets discharging to drains and enteric infection risk may vary by season.

Conclusions

The presence of a household toilet was associated with lower risk of bacterial and protozoal enteric infections, but not diarrhoea or viral infections, suggesting the health effects of sanitation may be more accurately estimated using outcome measures that account for aetiologic agents.

Hospitalizações de crianças por condições evitáveis no Estado do Paraná: causas e tendência

Resumo Objetivo Analisar a tendência das hospitalizações por condições sensíveis à atenção primária, segundo principais causas em menores de cinco anos. Métodos Estudo de séries temporais do tipo ecológico realizado com dados do Sistema de Informação Hospitalar do Estado do Paraná. A análise ocorreu a partir das taxas de hospitalização e de modelos de regressão polinomial segundo idade e causa. Resultados As causas mais frequentes foram pneumonias, gastrenterites, asma, infeção no rim e trato urinário e deficiências nutricionais. As hospitalizações por pneumonia, asma e deficiências nutricionais em menores de cinco anos reduziram e por gastroenterites mantiveram-se estáveis. Houve aumento nas taxas de hospitalização por infecção no rim e trato urinário em todas as idades. Conclusão A tendência de hospitalização por condições sensíveis em menores de cinco anos foi crescente apenas para as crianças menores de um ano. As hospitalizações por pneumonias, gastroenterites, asma e deficiências nutricionais apresentaram tendência decrescente.

Global burden of diarrheal disease attributable to the water supply and sanitation system in the State of Minas Gerais, Brazil: 2005

Advances have occurred in relation to the coverage of water supply and sanitation in Brazil, however inequalities are still observed in relation to the coverage of these services, reflecting the importance of diarrheal disease in the Brazilian epidemiological context. The aim of this study was to measure the impact of the water supply and sanitation system on diarrheal diseases among children aged under five. The global burden of diarrhea was calculated based on the attributable population fraction, using information on prevalence and relative risks from the 2000/2010 censuses and a study by Pruss et al. The north of the State of Minas Gerais, the Northeast and Jequitinhonha regions had the highest disability-adjusted life year (DALY) rates and ratios. The fraction of diarrhea attributable to the water supply and sanitation system was 83%, decreasing to 78.3% where sanitation had 100% coverage. An inverse relationship was found between DALY rates and attributable fractions and per capita GDP. Broadening the scope and coverage of services and improving the quality of water available in homes is an urgent requirement. These measures will bring economic and social benefits related to the reduction of diarrheal diseases and consequent improvement of the quality of life of children aged under five.

The Migrant Paradox in Children and the Role of Schools in Reducing Health Disparities: A Cross-Sectional Study of Migrant and Native Children in Beijing, China

Migrants usually exhibit similar or better health outcomes than native-born populations despite facing socioeconomic disadvantages and barriers to healthcare use; this is known as the “migrant paradox.” The migrant paradox among children is highly complex. This study explores whether the migrant paradox exists in the health of internal migrant children in China and the role of schools in reducing children’s health disparities, using a multi-stage stratified cluster sampling method. Participants were 1,641 student and parent pairs from Grades 4, 5, and 6 of eight primary schools in Beijing. The following school types were included: state schools with migrant children comprising over 70% of total children (SMS), private schools with migrant children comprising over 70% (PMS), and state schools with permanent resident children comprising over 70% (SRS). Children were divided into Groups A, B, C or D by the type of school they attended (A and B were drawn from SRSs, C was from SMSs, and D was from PMSs) and whether they were in the migrant population (B, C, and D were, but A was not). Related information was collected through medical examination and questionnaires completed by parents and children. Prevalence of caries, overweight and obesity, poor vision, and self-reported incidence of colds and diarrhea in the previous month were explored as health outcomes. The results partially demonstrated the existence of the migrant paradox and verified the role of schools in lowering health disparities among children; there are theoretical and practical implications for improving the health of migrant children.

Effect of a community-led sanitation intervention on child diarrhoea and child growth in rural Mali: a cluster-randomised controlled trial

BACKGROUND

Community-led total sanitation (CLTS) uses participatory approaches to mobilise communities to build their own toilets and stop open defecation. Our aim was to undertake the first randomised trial of CLTS to assess its effect on child health in Koulikoro, Mali.

METHODS

We did a cluster-randomised trial to assess a CLTS programme implemented by the Government of Mali. The study population included households in rural villages (clusters) from the Koulikoro district of Mali; every household had to have at least one child aged younger than 10 years. Villages were randomly assigned (1:1) with a computer-generated sequence by a study investigator to receive CLTS or no programme. Health outcomes included diarrhoea (primary outcome), height for age, weight for age, stunting, and underweight. Outcomes were measured 1·5 years after intervention delivery (2 years after enrolment) among children younger than 5 years. Participants were not masked to intervention assignment. The trial is registered with ClinicalTrials.gov, number NCT01900912.

FINDINGS

We recruited participants between April 12, and June 23, 2011. We assigned 60 villages (2365 households) to receive the CLTS intervention and 61 villages (2167 households) to the control group. No differences were observed in terms of diarrhoeal prevalence among children in CLTS and control villages (706 [22%] of 3140 CLTS children vs 693 [24%] of 2872 control children; prevalence ratio [PR] 0·93, 95% CI 0·76-1·14). Access to private latrines was almost twice as high in intervention villages (1373 [65%] of 2120 vs 661 [35%] of 1911 households) and reported open defecation was reduced in female (198 [9%] of 2086 vs 608 [33%] of 1869 households) and in male (195 [10%] of 2004 vs 602 [33%] of 1813 households) adults. Children in CLTS villages were taller (0·18 increase in height-for-age Z score, 95% CI 0·03-0·32; 2415 children) and less likely to be stunted (35% vs 41%, PR 0·86, 95% CI 0·74-1·0) than children in control villages. 22% of children were underweight in CLTS compared with 26% in control villages (PR 0·88, 95% CI 0·71-1·08), and the difference in mean weight-for-age Z score was 0·09 (95% CI -0·04 to 0·22) between groups. In CLTS villages, younger children at enrolment (<2 years) showed greater improvements in height and weight than older children.

INTERPRETATION

In villages that received a behavioural sanitation intervention with no monetary subsidies, diarrhoeal prevalence remained similar to control villages. However, access to toilets substantially increased and child growth improved, particularly in children <2 years. CLTS might have prevented growth faltering through pathways other than reducing diarrhoea.

FUNDING

Bill & Melinda Gates Foundation.

The effects of improved sanitation on diarrheal prevalence, incidence, and duration in children under five in the SNNPR State, Ethiopia: study protocol for a randomized controlled trial

Background

Diarrhea is one of the leading causes of death, killing 1.3 million in 2013 across the globe, of whom, 0.59 million were children under 5 years of age. Globally, about 1 billion people practice open defecation, and an estimated 2.4 billion people were living without improved sanitation facilities in 2015. Much of the previous research investigating the effect of improved sanitation has been based on observational studies. Recent studies have executed a cluster-randomized controlled trial to investigate the effect of improved sanitation. However, none of these recent studies achieved a sufficient level of latrine coverage. Without universal or at least a sufficient level of latrine coverage, a determination of the effect of improved latrines on the prevention of diarrheal disease is difficult.

This cluster-randomized trial aims to explore the net effect of improved latrines on diarrheal prevalence and incidence in children under five and to investigate the effect on the diarrheal duration.

Method/design

A phase-in and factorial design will be used for the study. The intervention for improving latrines will be implemented in an intervention arm during the first phase, and the comparable intervention will be performed in the control arm during the second phase. During the second phase, a water pipe will be connected to the gotts (villages) in the intervention arm. After the second phase is completed, the control group will undergo the intervention of receiving a water pipe connection. For diarrheal prevalence, five rounds of surveying will be conducted at the household level. The first four rounds will be carried out in the first phase to explore the effect of improved latrines, and the last one, in the second phase to examine the combined effects of improved water and sanitation. For documentation of diarrheal incidence and duration, the mother or caregiver will record the diarrheal episodes of her youngest child on the “Sanitation Calendar” every day. Of 212 gotts in the project area, 48 gotts were selected for the trial, and 1200 households with a child under 5 will be registered for the intervention or control arm. Informed consent from 1200 households will be obtained from the mother or caregiver in written form.

Discussion

To our knowledge, this is the second study to assess the effects of improved latrines on child diarrheal reduction through the application of Community-Led Total Sanitation.

Trial registration

Current Controlled Trials, ISRCTN82492848

Quantifying Contact with the Environment: Behaviors of Young Children in Accra, Ghana

To better understand the risks of exposure for young children to fecal contamination in their environment, we systematically characterized and quantified behaviors of 154 children, 0–5 years old, in four high-density, low-income neighborhoods in Accra, Ghana. A repertoire of six different activities and five different compartments (categories of locations within the household) was developed, and about 500 hours of ordered structured observations of activities and locations of individual children were collected. These records were analyzed using a competing hazards model, estimating (Weibull) hazard rates for each state (activity/compartment combination), dependent on the present state and the preceding state. The estimated rates were used to simulate sequences of behavior and describe days in the life of a child in low-income, urban Africa. Children younger than 1 year spent most time playing or sleeping off the ground, older children frequently played on floors. Relatively little time was spent in drains or wet trash areas. Critical combinations of activities, like handwashing after defecation or before eating were estimated to occur rarely. These quantitative behavior estimates can inform future risk assessments that examine the relative roles of various fecal–oral exposure pathways in low-income urban settings.

Comparison between Two Decades of Prevalence of Intestinal Parasitic Diseases and Risk Factors in a Brazilian Urban Centre

Objectives. This study's objective was to compare the prevalence of intestinal parasites and associated risk factors in children in urban communities, in the Brazilian Northeast, between two decades. Methods. This quantitative transversal study consisted of a comparative analysis of two different samples: the first viewing the years 1992-1996 and the other through a coproepidemiological data survey undertaken in 2010-2011. Results. It was evidenced that there was a reduction of intestinal parasites and that there were improvements in the socioenvironmental conditions between the two decades evaluated. It was observed that, in the period 1992-1996, playing out in the streets was associated with a higher risk for acquiring intestinal parasites. Over the 2010-2011 period, the characteristics of more than five residents per household, houses with dirt floors, children who live in homes without piped water, and children who play out in the streets were associated with a higher risk of intestinal parasitic infection. Conclusion. The study showed a reduction of intestinal parasitic diseases to 23.8% in 2010-2011 from 81.3% in 1992-1996 and improvement of the social-sanitary conditions of the population between the decades analyzed.

The MAL-ED study: a multinational and multidisciplinary approach to understand the relationship between enteric pathogens, malnutrition, gut physiology, physical growth, cognitive development, and immune responses in infants and children up to 2 years of age in resource-poor environments

Highly prevalent conditions with multiple and complex underlying etiologies are a challenge to public health. Undernutrition, for example, affects 20% of children in the developing world. The cause and consequence of poor nutrition are multifaceted. Undernutrition has been associated with half of all deaths worldwide in children aged <5 years; in addition, its pernicious long-term effects in early childhood have been associated with cognitive and physical growth deficits across multiple generations and have been thought to suppress immunity to further infections and to reduce the efficacy of childhood vaccines. The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health (MAL-ED) Study, led by the Fogarty International Center of the National Institutes of Health and the Foundation for the National Institutes of Health, has been established at sites in 8 countries with historically high incidence of diarrheal disease and undernutrition. Central to the study is the hypothesis that enteropathogen infection contributes to undernutrition by causing intestinal inflammation and/or by altering intestinal barrier and absorptive function. It is further postulated that this leads to growth faltering and deficits in cognitive development. The effects of repeated enteric infection and undernutrition on the immune response to childhood vaccines is also being examined in the study. MAL-ED uses a prospective longitudinal design that offers a unique opportunity to directly address a complex system of exposures and health outcomes in the community-rather than the relatively rarer circumstances that lead to hospitalization-during the critical period of development of the first 2 years of life. Among the factors being evaluated are enteric infections (with or without diarrhea) and other illness indicators, micronutrient levels, diet, socioeconomic status, gut function, and the environment. MAL-ED aims to describe these factors, their interrelationships, and their overall impact on health outcomes in unprecedented detail, and to make individual, site-specific, and generalized recommendations regarding the nature and timing of possible interventions aimed at improving child health and development in these resource-poor settings.

A simple microbiological tool to evaluate the effect of environmental health interventions on hand contamination

The effects of interventions such as sanitation or hand hygiene on hand contamination are difficult to evaluate. We explored the ability of a simple microbiological test to: (1) detect recontamination after handwashing; (2) reflect risk factors for microbial contamination and (3) be applicable to large populations. The study was done in rural Andhra Pradesh, India, and Maputo, Mozambique. Participants placed all 10 fingertips on a chromogenic agar that stains Enterococcus spp. and E. coli spp. Outcomes were the number of colonies and the number of fingertips with colonies. In the recontamination study, participants were randomised to handwashing with soap and no handwashing, and tested at 30 min intervals afterwards. In two cross sectional studies, risk factors for hand contamination were explored. Recontamination of hands after washing with soap was fast, with baseline levels reached after 1 h. Child care was associated with higher Enterococcus spp. counts, whereas agricultural activities increased E. coli spp. counts. Food preparation was associated with higher counts for both organisms. In Maputo, counts were not strongly associated with water access, latrine type, education or diarrhoea. The method seems unsuitable for the evaluation of handwashing promotion. It may reflect immediately preceding risk practices but not household-level risk factors.

Assessing the Health Impact of the following Measures in Schools in Maradi (Niger): Construction of Latrines, Clean Water Supply, Establishment of Hand Washing Stations, and Health Education

Objective. To assess the effect on health of the following measures in schools in Maradi (Niger): clean water supply, construction of latrines, establishment of hand washing stations, and health education. Methodology. It was a "before and after" intervention study on a sample of school children aged 7 to 12 years in the Maradi region. The interventions included building of latrines, supplying clean water, setting up hand washing stations, and teaching health education lessons. An individual questionnaire, analysis of stool samples, and a group questionnaire were administered to children and teachers, respectively. The threshold for significance was set at P < 0.05. Results. A statistically significant reduction in cases of diarrhoea and abdominal pains was noted after the project. Overall, carriage of at least one parasite increased from 7.5% before the project to 10.2% after it (P = 0.04). In the programme group schools, there was a statistically significant increase in the prevalence of Hymenolepis nana, from 0 to 1.9 (P = 0.02). Pinworm prevalence remained stable in this group but increased significantly in the control group. Conclusions. Putting health infrastructure in place in schools obviously had an impact on hygiene-related habits in the beneficiary schools and communities.

[Hospitalizations for primary care-sensitive conditions in a Southern Brazilian municipality]

OBJECTIVE

To study the most frequent causes of hospitalizations for primary care-sensitive conditions (HPCSC) in the city of Juiz de Fora, MG, Brazil, by age group and gender, over the periods of 2002 to 2005 and of 2006 to 2009.

METHODS

This was a descriptive study, with data collected from the Hospital Information System of the Unified Health System (Sistema de Informação Hospitalar do Sistema Único de Saúde - SIH-SUS) and from population projections by the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística - IBGE). HPCSC rates were calculated for 1,000 inhabitants, and the most frequent causes were studied by gender and age group, comparing both periods.

RESULTS

HPCSP showed rates of 7.74/1,000 between 2002 and 2005 and 8.81/1,000 between 2006 and 2009. The main causes were heart failure, cerebrovascular diseases, angina pectoris, pulmonary diseases, and kidney and urinary tract infections, which together represented 4.9/1,000 in the first period and 5.6/1,000 in the second period. The evolution of the rates between both periods occurred differently by age group and gender.

CONCLUSION

The study did not exhibit any remarkable differences in HPCSC rates between the periods. Regarding the most frequent causes, reduced hospitalization rates for gastroenteritis, asthma, high blood pressure, and cerebrovascular diseases were observed, as well as increased hospitalizations for heart failure, pulmonary diseases, epilepsies, and kidney and urinary tract infections; these hospitalizations occurred differently by gender and age group. The results showed that a deep reflection regarding the determinants of hospitalizations for avoidable causes is needed.

Prevalence of gastrointestinal pathogens in developed and developing countries: systematic review and meta-analysis

ABSTRACT

Diarrhoeal illness is a leading cause of child mortality and morbidity worldwide. There are no precise or current estimates of the types and prevalence of pathogens associated with diarrheal illnesses in developed and developing settings. This systematic review assessed data from 60 studies published in the English language from five developing regions and developed countries worldwide to provide regional estimates of enteric pathogens affecting children. The random-effect method was used to establish the weighted average prevalence of pathogens in adults and children for each region. Significantly more pathogens were reported by studies from developing regions compared with Organisation for Economic Co-operation and Development countries (P<0.016). The identification rates of pathogens from community based and hospital based studies were similar (58.5% and 58.1% respectively, P<0.619). The overall detection of enteric pathogens in developing countries was higher in adults (74.8%; 95% CI 63.1-83.8%) compared with children (56.7%; 95% CI 53.0-60.4%) (P<0.001). Rotavirus was the most frequently detected pathogen in all regions with the highest rate, 24.8% (95% CI 18.0-33.1%), detected in the developed countries. This systematic review is the first to provide an estimate of the prevalence of enteric pathogens associated with diarrhoeal illnesses in adults and children in developed and developing settings. While pathogen detection rate is greater in developing regions the consistently high prevalence of rotavirus in both developed and developing settings underscores the urgent need for access to rotavirus vaccines. Increased travel between developing and developed countries increases disease risk, and hence developed countries have a vested interest in supporting vaccine accessibility in developing settings.

Slum upgrading strategies involving physical environment and infrastructure interventions and their effects on health and socio-economic outcomes

BACKGROUND

Slums are densely populated, neglected parts of cities where housing and living conditions are exceptionally poor. In situ slum upgrading, at its basic level, involves improving the physical environment of the existing area, such as improving and installing basic infrastructure like water, sanitation, solid waste collection, electricity, storm water drainage, access roads and footpaths, and street lighting, as well as home improvements and securing land tenure.

OBJECTIVES

To explore the effects of slum upgrading strategies involving physical environment and infrastructure interventions on the health, quality of life and socio-economic wellbeing of urban slum dwellers in low and middle income countries (LMIC). Where reported, data were collected on the perspectives of slum dwellers regarding their needs, preferences for and satisfaction with interventions received.

SEARCH METHODS

We searched for published and unpublished studies in 28 bibliographic databases including multidisciplinary (for example Scopus) and specialist databases covering health, social science, urban planning, environment and LMIC topics. Snowballing techniques included searching websites, journal handsearching, contacting authors and reference list checking. Searches were not restricted by language or publication date.

SELECTION CRITERIA

We included studies examining the impact of slum upgrading strategies involving physical environment or infrastructure improvements (with or without additional co-interventions) on the health, quality of life and socio-economic wellbeing of LMIC urban slum dwellers. Randomised controlled trials (RCTs), controlled before and after studies (CBAs) and interrupted time series (ITS) were eligible for the main analysis. Controlled studies with only post-intervention data (CPI) and uncontrolled before and after (UBA) studies were included in a separate narrative to examine consistency of results and to supplement evidence gaps in the main analysis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias for each study. Differences between the included study interventions and outcomes precluded meta-analysis so the results were presented in a narrative summary with illustrative harvest plots. The body of evidence for outcomes within the main analysis was assessed according to GRADE as very low, low, moderate or high quality.

MAIN RESULTS

We identified 10,488 unique records, with 323 screened as full text. Five studies were included for the main analysis: one RCT with a low risk, two CBAs with a moderate risk and two CBAs with a high risk of bias. Three CBAs evaluated multicomponent slum upgrading strategies. Road paving only was evaluated in one RCT and water supply in one CBA. A total of 3453 households or observations were included within the four studies reporting sample sizes.Most health outcomes in the main studies related to communicable diseases, for which the body of evidence was judged to be low quality. One CBA with a moderate risk of bias found that diarrhoeal incidence was reduced in households which received water connections from a private water company (risk ratio (RR) 0.53; 95% confidence interval (CI) 0.27 to 1.04) and the severity of diarrhoeal episodes (RR 0.48; 95% CI 0.19 to 1.22). There was no effect for duration of diarrhoea. Road paving did not result in changes in parasitic infections or sickness in one RCT. After multicomponent slum upgrading, claims for a waterborne disease as opposed to a non-waterborne disease reduced (RR 0.64; 95% CI 0.27 to 0.98) in one CBA with a high risk of bias but there was no change in sanitation-related mortality in a CBA with a moderate risk of bias.The majority of socio-economic outcomes reported within the main studies related to financial poverty, for which the body of evidence was of very low quality. Results were mixed amongst the main studies; one RCT and two CBAs reported no effect on the income of slum dwellers following slum upgrading. One further CBA found significant reduction in monthly water expenditure (mean difference (MD) -17.11 pesos; 95% CI -32.6 to -1.62). One RCT also showed mixed results for employment variables, finding no effect on unemployment levels but increased weekly worked hours (MD 4.68; 95% CI -0.46 to 9.82) and lower risk of residents intending to migrate for work (RR 0.78; 95% CI 0.60 to 1.01).There was no evidence available to assess the impact of slum upgrading on non-communicable diseases or social capital. Maternal and perinatal conditions, infant mortality, nutritional deficiencies, injuries, self-reported quality of life, education and crime were evaluated in one study each.Nine supporting studies were included that measured varying outcomes (6794 households or observations within eight studies reporting sample sizes). One CPI evaluated cement flooring only while three UBAs and five CPIs evaluated multicomponent slum upgrading strategies. All studies but one had a high risk of bias.The studies reinforced main study findings for diarrhoea incidence and water-related expenditure. Findings for parasitic infections and financial poverty were inconsistent with the main studies. In addition, supporting studies reported a number of disparate outcomes that were not evaluated in the main studies.Five supporting studies included some limited information on slum dweller perspectives. They indicated the importance of appropriate siting of facilities, preference for private facilities, delivering synergistic interventions together, and ensuring that infrastructure was fit for purpose and systems were provided for cleaning, maintenance and repair.

AUTHORS' CONCLUSIONS

A high risk of bias within the included studies, heterogeneity and evidence gaps prevent firm conclusions on the effect of slum upgrading strategies on health and socio-economic wellbeing. The most common health and socio-economic outcomes reported were communicable diseases and indicators of financial poverty. There was a limited but consistent body of evidence to suggest that slum upgrading may reduce the incidence of diarrhoeal diseases and water-related expenditure. The information available on slum dwellers' perspectives provided some insight to barriers and facilitators for successful implementation and maintenance of interventions.The availability and use of reliable, comparable outcome measures to determine the effect of slum upgrading on health, quality of life and socio-economic wellbeing would make a useful contribution to new research in this important area. Given the complexity in delivering slum upgrading, evaluations should look to incorporate process and qualitative information alongside quantitative effectiveness data to determine which particular interventions work (or don't work) and for whom.

[The Family Health Strategy and hospital admissions of children under five years in Piauí State, Brazil]

Hospitalizations for some health conditions can be reduced by timely primary care with appropriate quality, especially in children. This study analyzed the trend in hospitalizations in children under five years of age in Piauí State, Brazil, from 2000 to 2010, according to groups of causes (ICD-10) and hospital admissions in 2010, based on the Brazilian List of Hospitalizations for Primary Care-Sensitive Conditions. The objectives were to identify changes in the hospital morbidity profile and to discuss their relationship to expansion of the Family Health Strategy (FHS) in the State. Piauí showed the highest proportional expansion of the FHS in Brazil, reaching an estimated coverage of 97.2% in 2010. From 2000 to 2010, there was a reduction in the hospitalization frequency and rates in children under five years, but the proportion of hospitalizations in the leading groups of causes persisted or increased during the decade. In 2010, 60% of hospitalizations in children under five years were for causes that are sensitive to primary care, especially infectious gastroenteritis, respiratory infections, and asthma.

Removing the neglect from neglected tropical diseases: the Rwandan experience 2008-2010

While there has been increasing recognition of the importance of neglected tropical diseases (NTDs), national scale action and funding remain limited. In 2007, a 3-year, $1 million per year programme was launched in Rwanda to address NTDs. While more than $100 million had flowed into Rwanda's health sector annually, not $1 was allocated for NTDs. This article describes the development of a national NTD strategy in Rwanda and outlines lessons learned, with particular regard to integrated approaches to NTD prevention. A baseline survey revealed that more than 65% of children had intestinal worms with high levels of concurrent multiple parasite infection. Within a year, mass treatment administration was provided for the first time. A repeat survey found that prevalence of soil-transmitted helminths and Schistosoma mansoni infection had been reduced significantly, including a reduction in prevalence of S. mansoni of 82% and of 72% in hookworm. Infection intensity and signs of early clinical morbidity also decreased significantly. Despite ongoing global neglect, the Rwandan NTD response presents a promising and unheralded success in science-based national public health action at scale. Looking forward, greater integration of the NTD response with water and sanitation activities are needed to consolidate impact and sustainably reduce the disease burden.

Urban inequities; urban rights: a conceptual analysis and review of impacts on children, and policies to address them

This paper explores current conceptual understanding of urban social, environmental, and health inequality and inequity, and looks at the impact of these processes on urban children and young people in the 21st century. This conceptual analysis was commissioned for a discussion paper for UNICEF's flagship publication: State of the World's Children 2012: Children in an Urban World. The aim of the paper is to examine evidence on the meaning of urban inequality and inequity for urban children and young people. It further looks at the controversial policies of targeting "vulnerable" young people, and policies to achieve the urban MDGs. Finally, the paper looks briefly at the potential of concepts such as environment justice and rights to change our understanding of urban inequality and inequity.

Toward a systems approach to enteric pathogen transmission: from individual independence to community interdependence

Diarrheal disease is still a major cause of mortality and morbidity worldwide; thus a large body of research has been produced describing its risks. We review more than four decades of literature on diarrheal disease epidemiology. These studies detail a progression in the conceptual understanding of transmission of enteric pathogens and demonstrate that diarrheal disease is caused by many interdependent pathways. However, arguments by diarrheal disease researchers in favor of attending to interaction and interdependencies have only recently yielded more formal systems-level approaches. Therefore, interdependence has not yet been highlighted in significant new research initiatives or policy decisions. We argue for a systems-level framework that will contextualize transmission and inform prevention and control efforts so that they can integrate transmission pathways. These systems approaches should be employed to account for community effects (i.e., interactions among individuals and/or households).

Sustainable sanitation technology options for urban slums

Poor sanitation in urban slums results in increased prevalence of diseases and pollution of the environment. Excreta, grey water and solid wastes are the major contributors to the pollution load into the slum environment and pose a risk to public health. The high rates of urbanization and population growth, poor accessibility and lack of legal status in urban slums make it difficult to improve their level of sanitation. New approaches may help to achieve the sanitation target of the Millennium Development Goal (MDG) 7; ensuring environmental sustainability. This paper reviews the characteristics of waste streams and the potential treatment processes and technologies that can be adopted and applied in urban slums in a sustainable way. Resource recovery oriented technologies minimise health risks and negative environmental impacts. In particular, there has been increasing recognition of the potential of anaerobic co-digestion for treatment of excreta and organic solid waste for energy recovery as an alternative to composting. Soil and sand filters have also been found suitable for removal of organic matter, pathogens, nutrients and micro-pollutants from grey water.

Neighborhood urban environmental quality conditions are likely to drive malaria and diarrhea mortality in Accra, Ghana

Background. Urbanization is a process which alters the structure and function of urban environments. The alteration in the quality of urban environmental conditions has significant implications for health. This applies both to the ecology of insect vectors that may transmit diseases and the burden of disease. Study Objectives. To investigate the relationship between malaria and infectious diarrhea mortality and spatially varied neighborhood environmental quality conditions in a low-income economy. Design. A one time point spatial analysis of cluster-level environmental conditions and mortality data using principal component analysis (PCA), one-way analysis of variance (ANOVA) and generalized linear models (GLMs). Methods. Environmental variables were extracted from the Ghana Census 2000 database while mortality data were obtained from the Ghana Births and Deaths Registry in Accra over the period 1998–2002. Results. Whereas there was a strong evidence of a difference in relative mortality of malaria across urban environmental zones of differing neighborhood environmental conditions, no such evidence of mortality differentials was observed for diarrhea. In addition, whereas bivariate analyses showed a weak to strong evidence of association between the environmental variables and malaria mortality, no evidence of association was found between diarrhea mortality and environmental variables. Conclusion. We conclude that environmental management initiatives intended for infectious disease control might substantially reduce the risk of urban malaria mortality and to a less extent that for urban diarrhea mortality in rapidly urbanizing areas in a low-income setting.

Hygiene, sanitation, and water: forgotten foundations of health

As the first article in a four-part PLoS Medicine series on water and sanitation, Jamie Bartram and Sandy Cairncross argue that the massive burden of ill health associated with poor hygiene, sanitation, and water supply demands more attention from health professionals and policymakers.

Principais causas de internação por condições sensíveis à atenção primária no Brasil: uma análise por faixa etária e região

OBJETIVOS: analisar as tendências das principais causas de internações hospitalares entre aquelas sensíveis à atenção primária (ICSAP) no Brasil, por faixa etária e região, no período de 1999 a 2006. MÉTODOS: trata-se de um estudo ecológico misto das tendências das três principais causas de ICSAP em menores de vinte anos. Os dados secundários foram provenientes do Sistema de Informação Hospitalar (SIH-SUS) e do censo demográfico do ano de 2001 e projeções populacionais do Instituto Brasileiro de Geografia e Estatística (IBGE). RESULTADOS: as três principais causas de ICSAP, em menores de 20 anos, foram as gastroenterites, asma e as pneumonias bacterianas. Houve redução das taxas de internação por gastroenterites (-12,0%) e asma (-31,8%) e, incremento de 142,5% nas taxas de internações por pneumonias bacterianas, tendências que ocorreram de forma distinta por faixa etária e região. CONCLUSÕES: a descrição das tendências temporais revelou mudanças positivas na evolução das taxas de internações por asma e gastroenterites infecciosas e negativas nas internações por pneumonia. Uma vez que estes problemas de saúde constituem objeto de intervenção prioritária na atenção primária, tais achados evidenciam a necessidade de se aprofundar a análise e reflexão sobre os determinantes do perfil das internações hospitalares no país.

Interventions to improve disposal of human excreta for preventing diarrhoea

BACKGROUND

Diarrhoeal diseases are a leading cause of mortality and morbidity, especially among young children in low-income countries, and are associated with exposure to human excreta.

OBJECTIVES

To assess the effectiveness of interventions to improve the disposal of human excreta for preventing diarrhoeal diseases.

SEARCH STRATEGY

We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library; MEDLINE; EMBASE; LILACS; the metaRegister of Controlled Trials (mRCT); and Chinese-language databases available under the Wan Fang portal, and the China National Knowledge Infrastructure (CNKI-CAJ). We also handsearched relevant conference proceedings, and contacted researchers and organizations working in the field, as well as checking references from identified studies.

SELECTION CRITERIA

Randomized, quasi-randomized, and non-randomized controlled trials (RCTs) were selected, comparing interventions aimed at improving the disposal of human excreta to reduce direct or indirect human contact with no such intervention. Cluster (eg at the level of household or community) controlled trials were included.

DATA COLLECTION AND ANALYSIS

We determined study eligibility, extracted data, and assessed methodological quality in accordance with the methods prescribed by the protocol. We described the results and summarized the information in tables. Due to substantial heterogeneity among the studies in terms of study design and type of intervention, no pooled effects were calculated.

MAIN RESULTS

Thirteen studies from six countries covering over 33,400 children and adults in rural, urban, and school settings met the review's inclusion criteria. In all studies the intervention was allocated at the community level. While the studies reported a wide range of effects, 11 of the 13 studies found the intervention was protective against diarrhoea. Differences in study populations and settings, in baseline sanitation levels, water, and hygiene practices, in types of interventions, study methodologies, compliance and coverage levels, and in case definitions and outcome surveillance limit the comparability of results of the studies included in this review. The validity of most individual study results are further compromised by the non-random allocation of the intervention among study clusters, an insufficient number of clusters, the lack of adjustment for clustering, unclear loss to follow-up, potential for reporting bias and other methodological shortcomings.

AUTHORS' CONCLUSIONS

This review provides some evidence that interventions to improve excreta disposal are effective in preventing diarrhoeal disease. However, this conclusion is based primarily on the consistency of the evidence of beneficial effects. The quality of the evidence is generally poor and does not allow for quantification of any such effect. The wide range of estimates of the effects of the intervention may be due to clinical and methodological heterogeneity among the studies, as well as to other important differences, including exposure levels, types of interventions, and different degrees of observer and respondent bias. Rigorous studies in multiple settings are needed to clarify the potential effectiveness of excreta disposal on diarrhoea.