Associations between Shared Sanitation, Stunting and Diarrhoea in Low-Income, High Density Urban Neighbourhoods of Maputo, Mozambique - a Cross-Sectional Study.

INTRODUCTION: Shared sanitation facilities are used by over 500 million people around the world. Most research evidence indicates that shared sanitation conveys higher risk than household sanitation for many adverse health outcomes. However, studies often fail to account for variation between different types of shared facilities. As informal housing development outpaces sanitation infrastructure, it is imperative to understand which components of shared facilities may mitigate the health risks of shared sanitation use. METHODS: This cross-sectional study determines whether sanitation improvement or compound hygiene were associated with stunting or diarrhoeal prevalence in children under five living in Maputo, Mozambique who rely on shared sanitation facilities. The study uses logistic and linear multivariable regression analysis to search for associations and control for potential confounding factors. RESULTS: 346 children (43.9%) in the study population were stunted. Each unit increase in sanitation score was associated with an approximate decrease of 22% in the odds of stunting (OR: 0.78, CI: 0.66, 0.92), and an increase in height of 0.23 height-for-age z-scores (CI: 0.10, 0.36). There was no evidence that the compound hygiene score was associated with height as measured by stunting (OR: 1.05, CI: 0.87, 1.26) or z-score (-0.06, CI: -0.21, 0.09). Neither sanitation nor compound hygiene score were associated with diarrhoea in the population. CONCLUSIONS: Use of an improved shared latrine is associated with decreased odds of stunting. There is no evidence of an association between latrine improvement and diarrhoea. Further investigation is necessary to isolate attributes of shared sanitation facilities that may reduce health risks.

Urban Onsite Sanitation Upgrades and Synanthropic Flies in Maputo, Mozambique: Effects on Enteric Pathogen Infection Risks.

Synanthropic filth flies transport enteric pathogens from feces to food, which upon consumption poses an infection risk. We evaluated the effect of an onsite sanitation intervention─including fly control measures─in Maputo, Mozambique, on the risk of infection from consuming fly-contaminated food. After enumerating flies at intervention and control sites, we cultured fecal indicator bacteria, quantified gene copies for 22 enteric pathogens via reverse transcription quantitative polymerase chain reaction (RT-qPCR), and developed quantitative microbial risk assessment (QMRA) models to estimate annual risks of infection attributable to fly-contaminated foods. We found that the intervention reduced fly counts at latrine entrances by 69% (aRR = 0.31, [0.13, 0.75]) but not at food preparation areas (aRR = 0.92, [0.33, 2.6]). Half of (23/46) of individual flies were positive for culturable Escherichia coli, and we detected ≥1 pathogen gene from 45% (79/176) of flies, including enteropathogenic E. coli (37/176), adenovirus (25/176), Giardia spp. (13/176), and Trichuris trichiura (12/176). We detected ≥1 pathogen gene from half the flies caught in control (54%, 30/56) and intervention compounds (50%, 17/34) at baseline, which decreased 12 months post-intervention to 43% (23/53) at control compounds and 27% (9/33) for intervention compounds. These data indicate flies as a potentially important mechanical vector for enteric pathogen transmission in this setting. The intervention may have reduced the risk of fly-mediated enteric infection for some pathogens, but infrequent detection resulted in wide confidence intervals; we observed no apparent difference in infection risk between groups in a pooled estimate of all pathogens assessed (aRR = 0.84, [0.61, 1.2]). The infection risks posed by flies suggest that the design of sanitation systems and service delivery should include fly control measures to prevent enteric pathogen transmission.

Persistent Ascaris Transmission Is Possible in Urban Areas Even Where Sanitation Coverage Is High.

In low-income, urban, informal communities lacking sewerage and solid waste services, onsite sanitation (sludges, aqueous effluent) and child feces are potential sources of human fecal contamination in living environments. Working in informal communities of urban Maputo, Mozambique, we developed a quantitative, stochastic, mass-balance approach to evaluate plausible scenarios of localized contamination that could explain why the soil-transmitted helminth Ascaris remains endemic despite nearly universal coverage of latrines that sequester most fecal wastes. We used microscopy to enumerate presumptively viable Ascaris ova in feces, fecal sludges, and soils from compounds (i.e., household clusters) and then constructed a steady-state mass-balance model to evaluate possible contamination scenarios capable of explaining observed ova counts in soils. Observed Ascaris counts (mean = -0.01 log10 ova per wet gram of soil, sd = 0.71 log10) could be explained by deposits of 1.9 grams per day (10th percentile 0.04 grams, 90th percentile 84 grams) of child feces on average, rare fecal sludge contamination events that transport 17 kg every three years (10th percentile 1.0 kg, 90th percentile 260 kg), or a daily discharge of 2.7 kg aqueous effluent from an onsite system (10th percentile 0.09 kg, 90th percentile 82 kg). Results suggest that even limited intermittent flows of fecal wastes in this setting can result in a steady-state density of Ascaris ova in soils capable of sustaining transmission, given the high prevalence of Ascaris shedding by children (prevalence = 25%; mean = 3.7 log10 per wet gram, sd = 1.1 log10), the high Ascaris ova counts in fecal sludges (prevalence = 88%; mean = 1.8 log10 per wet gram, sd = 0.95 log10), and the extended persistence and viability of Ascaris ova in soils. Even near-universal coverage of onsite sanitation may allow for sustained transmission of Ascaris under these conditions.

Measuring and valuing broader impacts in public health: Development of a sanitation-related quality of life instrument in Maputo, Mozambique.

Two billion people globally lack access to a basic toilet. While improving sanitation reduces infectious disease, toilet users often identify privacy, safety and dignity as more important. However, these outcomes have not been incorporated in sanitation-related economic evaluations. This illustrates the general challenge of outcome measurement and valuation in the economic evaluation of public health interventions, and risks misallocating the US$ 20 billion invested in sanitation in low- and middle-income countries every year. In this study in urban Mozambique, we develop an instrument to measure sanitation-related quality of life (SanQoL). Applying methods from health economics and the capability approach, we develop a descriptive system to measure five attributes identified in prior qualitative research: disgust, health, shame, safety and privacy. Sampling individuals from the intervention and control groups of a sanitation intervention trial, we elicit attribute ranks to value a SanQoL index and assess its validity and reliability. In combination with a measure of time using a sanitation service, SanQoL can quantify incremental benefits in a sanitation-focused cost-effectiveness analysis. After monetary valuation based on willingness to pay, QoL benefits could be summed with health gains in cost-benefit analysis, the most common method in sanitation economic evaluations.

Quantitative Microbial Risk Assessment of Pediatric Infections Attributable to Ingestion of Fecally Contaminated Domestic Soils in Low-Income Urban Maputo, Mozambique.

Rigorous studies of water, sanitation, and hygiene interventions in low- and middle-income countries (LMICs) suggest that children are exposed to enteric pathogens via multiple interacting pathways, including soil ingestion. In 30 compounds (household clusters) in low-income urban Maputo, Mozambique, we cultured Escherichia coli and quantified gene targets from soils (E. coli: ybbW, Shigella/enteroinvasive E. coli (EIEC): ipaH, Giardia duodenalis: ß-giardin) using droplet digital PCR at three compound locations (latrine entrance, solid waste area, dishwashing area). We found that 88% of samples were positive for culturable E. coli (mean = 3.2 log10 CFUs per gram of dry soil), 100% for molecular E. coli (mean = 5.9 log10 gene copies per gram of dry soil), 44% for ipaH (mean = 2.5 log10), and 41% for ß-giardin (mean = 2.1 log10). Performing stochastic quantitative microbial risk assessment using soil ingestion parameters from an LMIC setting for children 12-23 months old, we estimated that the median annual infection risk by G. duodenalis was 7100-fold (71% annual infection risk) and by Shigella/EIEC was 4000-fold (40% annual infection risk) greater than the EPA's standard for drinking water. Compounds in Maputo, and similar settings, require contact and source control strategies to reduce the ingestion of contaminated soil and achieve acceptable levels of risk.

Impacts of an Urban Sanitation Intervention on Fecal Indicators and the Prevalence of Human Fecal Contamination in Mozambique.

Fecal source tracking (FST) may be useful to assess pathways of fecal contamination in domestic environments and to estimate the impacts of water, sanitation, and hygiene (WASH) interventions in low-income settings. We measured two nonspecific and two human-associated fecal indicators in water, soil, and surfaces before and after a shared latrine intervention from low-income households in Maputo, Mozambique, participating in the Maputo Sanitation (MapSan) trial. Up to a quarter of households were impacted by human fecal contamination, but trends were unaffected by improvements to shared sanitation facilities. The intervention reduced Escherichia coli gene concentrations in soil but did not impact culturable E. coli or the prevalence of human FST markers in a difference-in-differences analysis. Using a novel Bayesian hierarchical modeling approach to account for human marker diagnostic sensitivity and specificity, we revealed a high amount of uncertainty associated with human FST measurements and intervention effect estimates. The field of microbial source tracking would benefit from adding measures of diagnostic accuracy to better interpret findings, particularly when FST analyses convey insufficient information for robust inference. With improved measures, FST could help identify dominant pathways of human and animal fecal contamination in communities and guide the implementation of effective interventions to safeguard health.

Impact of an Urban Sanitation Intervention on Enteric Pathogen Detection in Soils.

Environmental fecal contamination is common in many low-income cities, contributing to a high burden of enteric infections and associated negative sequelae. To evaluate the impact of a shared onsite sanitation intervention in Maputo, Mozambique on enteric pathogens in the domestic environment, we collected 179 soil samples at shared latrine entrances from intervention (n = 49) and control (n = 51) compounds during baseline (preintervention) and after 24 months (postintervention) as part of the Maputo Sanitation Trial. We tested soils for the presence of nucleic acids associated with 18 enteric pathogens using a multiplex reverse transcription qPCR platform. We detected at least one pathogen-associated gene target in 91% (163/179) of soils and a median of 3 (IQR = 1, 5) pathogens. Using a difference-in-difference analysis and adjusting for compound population, visibly wet soil, sun exposure, wealth, temperature, animal presence, and visible feces, we estimate the intervention reduced the probability of detecting ≥1 pathogen gene by 15% (adjusted prevalence ratio, aPR = 0.85; 95% CI: 0.70, 1.0) and the total number of pathogens by 35% (aPR = 0.65; 0.44, 0.95) in soil 24 months following the intervention. These results suggest that the intervention reduced the presence of some fecal contamination in the domestic environment, but pathogen detection remained prevalent 24 months following the introduction of new latrines.

Using path analysis to test theory of change: a quantitative process evaluation of the MapSan trial.

BACKGROUND: Although theory-driven evaluations should have empirical components, few evaluations of public health interventions quantitatively test the causal model made explicit in the theory of change (ToC). In the context of a shared sanitation trial (MapSan) in Maputo, Mozambique, we report findings of a quantitative process evaluation assessing intervention implementation, participant response and impacts on hypothesised intermediary outcomes on the pathway to trial health outcomes. We examine the utility of path analysis in testing intervention theory using process indicators from the intervention's ToC. METHODS: Process data were collected through a cross-sectional survey of intervention and control compounds of the MapSan trial > 24-months post-intervention, sampling adult residents and compound leaders. Indicators of implementation fidelity (dose received, reach) and participant response (participant behaviours, intermediary outcomes) were compared between trial arms. The intervention's ToC (formalised post-intervention) was converted to an initial structural model with multiple alternative pathways. Path analysis was conducted through linear structural equation modelling (SEM) and generalised SEM (probit model), using a model trimming process and grouped analysis to identify parsimonious models that explained variation in outcomes, incorporating demographics of respondents and compounds. RESULTS: Among study compounds, the MapSan intervention was implemented with high fidelity, with a strong participant response in intervention compounds: improvements were made to intermediary outcomes related to sanitation 'quality' - latrine cleanliness, maintenance and privacy - but not to handwashing (presence of soap / soap residue). These outcomes varied by intervention type: single-cabin latrines or multiple-cabin blocks (designed for > 20 users). Path analysis suggested that changes in intermediary outcomes were likely driven by direct effects of intervention facilities, with little contribution from hygiene promotion activities nor core elements expected to mediate change: a compound sanitation committee and maintenance fund. A distinct structural model for two compound size subgroups (≤ 20 members vs. > 20 members) explained differences by intervention type, and other contextual factors influenced specific model parameters. CONCLUSIONS: While process evaluation found that the MapSan intervention achieved sufficient fidelity and participant response, the path analysis approach applied to test the ToC added to understanding of possible 'mechanisms of change', and has value in disentangling complex intervention pathways. TRIAL REGISTRATION: MapSan trial registration: NCT02362932 Feb-13-2015.

Risk factors for child food contamination in low-income neighbourhoods of Maputo, Mozambique: An exploratory, cross-sectional study.

In low- and middle-income countries, food may be a critical transmission route for pathogens causing childhood diarrhoea, but basic food hygiene is often overlooked in public health strategies. Characterising child food contamination and its risk factors could help prioritise interventions to reduce foodborne diarrhoeal disease, especially in low-income urban areas where the diarrhoeal disease burden is often high. This cross-sectional study comprised a caregiver questionnaire coupled with food sampling, and food preparation observations, among the study population of an ongoing sanitation trial in Maputo. The aim was to determine the prevalence of child food contamination and associated risk factors. The prevalence of Enterococcus spp., as an indicator of faecal contamination, was estimated in food samples. Risk factor analyses were performed through zero-inflated negative binomial regression on colony counts. A modified hazard analysis and critical control point approach was used to determine critical control points (CCPs) that might effectively reduce risk. Fifty-eight linked caregiver questionnaires and food samples were collected, and 59 food preparation observations were conducted. The prevalence of enterococci in child foods exceeding 10 colony forming units per gram was 53% (95% confidence interval [40%, 67%]). Risk factors for child food contamination were identified, including type of food, food preparation practices, and hygiene behaviours. CCPs included cooking/reheating of food and food storage and handling. This exploratory study highlights the need for more research into diarrhoeagenic pathogens and foodborne risks for children living in these challenging urban environments.

Bisexual and Bidirectional: Assessing the Potential for HIV Bridging in Mozambique.

African men who have sex with men (MSM) frequently, and often concurrently, have female partners, raising concerns about HIV sexual bridging. We explored potential HIV transmission in Mozambique from and to female partners of MSM focusing on preferred anal sex role and circumcision status. Data collected in a respondent-driven sampling study of MSM in 2011 in Maputo and Beira. Men who had oral or anal sex with other men 12 months prior completed a questionnaire and consented for HIV testing. Statistical analysis explored demographic/risk characteristics and associations among circumcision status, anal sex with men, sexual positions during anal sex with men and vaginal or anal sex with women. We identified 326 MSM in Maputo and 237 in Beira with both male and female partners 3 months before the study. Of these, 20.8% in Maputo and 36.0% in Beira had any receptive anal sex with men 12 months prior, including 895 unprotected sexual acts with males in Maputo and 692 in Beira. Uncircumcised and exclusively insertive males, 27.7% of the sample in Maputo and 33.6% in Beira, had the most unprotected sex with females: 1159 total acts in Maputo and 600 in Beira. Sexual bridging between MSM and women likely varies geographically and is probably bi-directional, occurring within a generalized epidemic where HIV prevalence is higher among reproductive-age women than MSM. Prevention strategies emphasizing correct and consistent condom use for all partners and circumcision for bisexual men should be considered.

Shared latrines in Maputo, Mozambique: exploring emotional well-being and psychosocial stress.

BACKGROUND: Approximately 18% of Sub-Saharan Africa's urban population relies on shared sanitation facilities, which are shared by one or more households. While there is growing recognition of sanitation's relationship with stress and well-being - particularly among women - most research has focused on rural populations and the transition from open defecation and/or unimproved latrines to private shared sanitation. This study explores sanitation-related stressors among users of both improved and unimproved shared sanitation facilities. METHODS: This study was nested within the larger MapSan health impact trial (Trial Registration: NCT02362932). Participants were recruited from the control arm of the trial (Traditional Latrine (TL) users) and intervention arm, which received one of two improved shared sanitation facilities - Shared Latrines (SL) shared by up to 20 individuals and Community Sanitation Blocks (CSBs) shared by more than 20 individuals. Sampling was informed by a life stage perspective to reflect diversity in sanitation needs and experiences within the population. Data included 96 in-depth interviews, 7 focus group discussions, and 25 unstructured observations. Data collection and analysis followed a Grounded Theory approach, which was used to identify the key domains of sanitation-related stress among participants. A semi-structured tool was applied to all female interview transcripts to assess the frequency and severity of key stressors. RESULTS: Participants reported stress due to: lack of safety; lack of privacy; disgust about the latrine condition; and collective action failure in terms of managing the latrine, often causing neighborhood conflict or unhygienic sanitation conditions. Fewer SL and CSB users reported specific stress domains and - with the exception of perceived safety - reported fewer severe stressors. The leading cause of stress reduction due to the intervention was decreased disgust followed by increased privacy and safety. CONCLUSIONS: Our data suggest that "improved", shared facilities can reduce stress when proper maintenance and management systems are in place. Private, shared sanitation only had limited impact on users' perceptions of safety, particularly at night, suggesting that safety concerns extend beyond the physical latrine structure. Our research demonstrates that factors including latrine location and neighborhood violence are important determinants of safety perceptions and corresponding psychosocial stress.

Protocol and baseline data for a multi-year cohort study of the effects of different mass drug treatment approaches on functional morbidities from schistosomiasis in four African countries.

BACKGROUND: The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) focus is on randomized trials of different approaches to mass drug administration (MDA) in endemic countries in Africa. Because their studies provided an opportunity to evaluate the effects of mass treatment on Schistosoma-associated morbidity, nested cohort studies were developed within SCORE's intervention trials to monitor changes in a suite of schistosomiasis disease outcomes. This paper describes the process SCORE used to select markers for prospective monitoring and the baseline prevalence of these morbidities in four parallel cohort studies. METHODS: In July 2009, SCORE hosted a discussion of the potential impact of MDA on morbidities due to Schistosoma infection that might be measured in the context of multi-year control. Candidate markers were reviewed and selected for study implementation. Baseline data were then collected from cohorts of children in four country studies: two in high endemic S. mansoni sites (Kenya and Tanzania), and two in high endemic S. haematobium sites (Niger and Mozambique), these cohorts to be followed prospectively over 5 years. RESULTS: At baseline, 62% of children in the S. mansoni sites had detectable eggs in their stool, and 10% had heavy infections (≥ 400 eggs/g feces). Heavy S. mansoni infections were found to be associated with increased baseline risk of anemia, although children with moderate or heavy intensity infections had lower risk of physical wasting. Prevalence of egg-positive infection in the combined S. haematobium cohorts was 27%, with 5% of individuals having heavy infection (≥50 eggs/10 mL urine). At baseline, light intensity S. haematobium infection was associated with anemia and with lower scores in the social domain of health-related quality-of-life (HRQoL) assessed by Pediatric Quality of Life Inventory. CONCLUSIONS: Our consensus on practical markers of Schistosoma-associated morbidity indicated that height, weight, hemoglobin, exercise tolerance, HRQoL, and ultrasound abnormalities could be used as reference points for gauging treatment impact. Data collected over five years of program implementation will provide guidance for future evaluation of morbidity control in areas endemic for schistosomiasis. TRIAL REGISTRATION: These cohort studies are registered and performed in conjunction with the International Standard Randomised Controlled Trial Registry trials ISRCTN16755535 , ISRCTN14117624 , ISRCTN95819193 , and ISRCTN32045736 .

Risk Factors Associated with HIV Among Men Who Have Sex Only with Men and Men Who Have Sex with Both Men and Women in Three Urban Areas in Mozambique.

Using respondent-driven sampling (RDS), an integrated biological behavioral survey among men that have sex with men (MSM) enrolled 457 participants in Maputo [63.0 % were MSM who had sex with women (MSMW)], 538 in Beira (36.2 % MSMW) and 330 in Nampula-Nacala (54.8 % MSMW) in 2011. Analysis suggests that MSM who have sex only with men (MSMO) had increased odds of having HIV (aOR 2.7) compared to MSMW. HIV among MSMO associated with age, self-reported STI (aOR 4.2), having a single male anal partner (aOR 3.8) and having transactional sex with a man (aOR 3.5) in the past year. Among MSMW, HIV associated with age, lower education (aOR 32.5), being uncircumcised (aOR 3.1) and having transactional sex with a woman (aOR 6.0) in the past year. Findings confirm that MSMO and MSMW have distinct HIV risks in Mozambique; HIV programs for MSM in Southern Africa should take such differences into consideration.

Correlates of HIV Testing Among Men Who have Sex with Men in Three Urban Areas of Mozambique: Missed Opportunities for Prevention.

This is the first study to identify levels of recent HIV testing and associated factors among men who have sex with men (MSM) in Mozambique. Using data from Maputo (n = 493), Beira (n = 572), and Nampula/Nacala (n = 347), collected via respondent-driven sampling in 2011, and excluding those with prior known infection, we found that 30.4 % [95 % confidence interval (CI) 25.0-36.3 %], 42.1 % (95 % CI 36.8-47.3 %) and 29.8 % (95 % CI 22.9-36.9 %), respectively, had recently tested for HIV (≤12 months), while between three and five out of 10 MSM had never tested. A range of factors was associated with recent HIV testing such as familiarity with the modes of transmission, knowledge of antiretroviral treatment for HIV, contact with peer educators and awareness of partner serostatus; yet, surprisingly recent healthcare utilization was not associated with recent testing. Findings provide evidence that structural and behavioral interventions among MSM may play an important role in increasing HIV testing.

Men who have sex with men in Mozambique: identifying a hidden population at high-risk for HIV.

The population of men who have sex with men (MSM) has been largely ignored in HIV-related policies and programming in Mozambique and there is little information about the contribution of MSM to the HIV epidemic. An integrated biological and behavioral study among MSM using respondent-driven sampling was conducted in 2011 in Maputo, Beira and Nampula/Nacala. Men who reported engaging in oral or anal sex with other men in the last 12 months answered a questionnaire and provided a blood sample for HIV testing. The prevalence of HIV was 8.2 % (Maputo, n = 496), 9.1 % (Beira, n = 584) and 3.1 % (Nampula/Nacala, n = 353). Prevalence was higher among MSM ≥ 25 vs. 18-24 years: 33.8 % vs. 2.4 % (p < 0.001), 32.1 vs. 2.8 % (p < 0.001), and 10.3 vs. 2.7 % (p < 0.06), in each city respectively. The difference in prevalence demonstrates the need to increase prevention for younger MSM at risk for HIV and ensure care and treatment for older HIV-infected MSM.

Sanitation in urban areas may limit the spread of antimicrobial resistance via flies.

Synanthropic filth flies are common where sanitation is poor and fecal wastes are accessible to them. These flies have been proposed as mechanical vectors for the localized transport of fecal microbes including antimicrobial resistant (AMR) organisms and associated antimicrobial resistance genes (ARGs), increasing exposure risks. We evaluated whether an onsite sanitation intervention in Maputo, Mozambique reduced the concentration of enteric bacteria and the frequency of detection of ARGs carried by flies collected in household compounds of low-income neighborhoods. Additionally, we assessed the phenotypic resistance profile of Enterobacteriaceae isolates recovered from flies during the pre-intervention phase. After fly enumeration at study compounds, quantitative polymerase chain reaction was used to quantify an enteric 16S rRNA gene (i.e., specific to a cluster of phylotypes corresponding to 5% of the human fecal microflora), 28 ARGs, and Kirby Bauer Disk Diffusion of Enterobacteriaceae isolates was utilized to assess resistance to eleven clinically relevant antibiotics. The intervention was associated with a 1.5 log10 reduction (95% confidence interval: -0.73, -2.3) in the concentration of the enteric 16S gene and a 31% reduction (adjusted prevalence ratio = 0.69, [0.52, 0.92]) in the mean number of ARGs per fly compared to a control group with poor sanitation. This protective effect was consistent across the six ARG classes that we detected. Enterobacteriaceae isolates-only from the pre-intervention phase-were resistant to a mean of 3.4 antibiotics out of the eleven assessed. Improving onsite sanitation infrastructure in low-income informal settlements may help reduce fly-mediated transmission of enteric bacteria and the ARGs carried by them.

Is detection of enteropathogens and human or animal faecal markers in the environment associated with subsequent child enteric infections and growth: an individual participant data meta-analysis.

BACKGROUND: Quantifying contributions of environmental faecal contamination to child diarrhoea and growth faltering can illuminate causal mechanisms behind modest health benefits in recent water, sanitation, and hygiene (WASH) trials. We aimed to assess associations between environmental detection of enteropathogens and human or animal microbial source tracking markers (MSTM) and subsequent child health outcomes. METHODS: In this individual participant data meta-analysis we searched we searched PubMed, Embase, CAB Direct Global Health, Agricultural and Environmental Science Database, Web of Science, and Scopus for WASH intervention studies with a prospective design and concurrent control that measured enteropathogens or MSTM in environmental samples, or both, and subsequently measured enteric infections, diarrhoea, or height-for-age Z-scores (HAZ) in children younger than 5 years. We excluded studies that only measured faecal indicator bacteria. The initial search was done on Jan 19, 2021, and updated on March 22, 2023. One reviewer (AM) screened abstracts, and two independent reviewers (AM and RT) examined the full texts of short-listed articles. All included studies include at least one author that also contributed as an author to the present Article. Our primary outcomes were the 7-day prevalence of caregiver-reported diarrhoea and HAZ in children. For specific enteropathogens in the environment, primary outcomes also included subsequent child infection with the same pathogen ascertained by stool testing. We estimated associations using covariate-adjusted regressions and pooled estimates across studies. FINDINGS: Data from nine published reports from five interventions studies, which included 8603 children (4302 girls and 4301 boys), were included in the meta-analysis. Environmental pathogen detection was associated with increased infection prevalence with the same pathogen and lower HAZ (ΔHAZ -0·09 [95% CI -0·17 to -0·01]) but not diarrhoea (prevalence ratio 1·22 [95% CI 0·95 to 1·58]), except during wet seasons. Detection of MSTM was not associated with diarrhoea (no pooled estimate) or HAZ (ΔHAZ -0·01 [-0·13 to 0·11] for human markers and ΔHAZ -0·02 [-0·24 to 0·21] for animal markers). Soil, children's hands, and stored drinking water were major transmission pathways. INTERPRETATION: Our findings support a causal chain from pathogens in the environment to infection to growth faltering, indicating that the lack of WASH intervention effects on child growth might stem from insufficient reductions in environmental pathogen prevalence. Studies measuring enteropathogens in the environment should subsequently measure the same pathogens in stool to further examine theories of change between WASH, faecal contamination, and health. Given that environmental pathogen detection was predictive of infection, programmes targeting specific pathogens (eg, vaccinations and elimination efforts) can environmentally monitor the pathogens of interest for population-level surveillance instead of collecting individual biospecimens. FUNDING: The Bill & Melinda Gates Foundation and the UK Foreign and Commonwealth Development Office.

Regional Differences in Intestinal Parasitic Infections among Army Recruits in a Southern Mozambique Training Center: A Cross-Sectional Study.

Due to the high prevalence and diversity of clinical manifestations, intestinal parasitic infections (IPIs) represent a public health problem. The objective of the work was to determine the prevalence of IPIs among army recruits at a practice and training center in southern Mozambique. Sociodemographic information was obtained through semi-structured interviews. Single urine and stool samples were collected from 362 recruits. Parasite diagnosis was made by filtration, formaldehyde-ether and Kato-Katz techniques. Positive individuals underwent abdominal ultrasound. Then, descriptive statistics and cross-tabulations were performed, and p-values < 0.05 were considered significant. The prevalence of infection with at least one parasite was 25.1% (95% CI: 20.5-29.6; n = 91). The most common parasites were Entamoeba coli (10.7%; 95% CI: 7.4-13.7; n = 37) and Trichuris trichiura (6.1%; 95% CI: 4.6-9.9; n = 25). Parasitic infection was associated with the origin of the participant (p-value < 0.001), and the province of Sofala had the highest prevalence among the provinces studied (70.6%; 95% CI: 47.0-87.8; 12/17). Since oral fecal transmission occurs for several parasites, routine screening and deworming prior to enrollment at the army training center is recommended to reduce transmission of intestinal parasites among recruits.

Long-term impacts of an urban sanitation intervention on enteric pathogens in children in Maputo city, Mozambique: study protocol for a cross-sectional follow-up to the Maputo Sanitation (MapSan) trial 5 years postintervention.

INTRODUCTION: We previously assessed the effect of an onsite sanitation intervention in informal neighbourhoods of urban Maputo, Mozambique on enteric pathogen detection in children after 2 years of follow-up (Maputo Sanitation (MapSan) trial, ClinicalTrials.gov: NCT02362932). We found significant reductions in Shigella and Trichuris prevalence but only among children born after the intervention was delivered. In this study, we assess the health impacts of the sanitation intervention after 5 years among children born into study households postintervention. METHODS AND ANALYSIS: We are conducting a cross-sectional household study of enteric pathogen detection in child stool and the environment at compounds (household clusters sharing sanitation and outdoor living space) that received the pour-flush toilet and septic tank intervention at least 5 years prior or meet the original criteria for trial control sites. We are enrolling at least 400 children (ages 29 days to 60 months) in each treatment arm. Our primary outcome is the prevalence of 22 bacterial, protozoan, and soil transmitted helminth enteric pathogens in child stool using the pooled prevalence ratio across the outcome set to assess the overall intervention effect. Secondary outcomes include the individual pathogen detection prevalence and gene copy density of 27 enteric pathogens (including viruses); mean height-for-age, weight-for-age, and weight-for-height z-scores; prevalence of stunting, underweight, and wasting; and the 7-day period prevalence of caregiver-reported diarrhoea. All analyses are adjusted for prespecified covariates and examined for effect measure modification by age. Environmental samples from study households and the public domain are assessed for pathogens and faecal indicators to explore environmental exposures and monitor disease transmission. ETHICS AND DISSEMINATION: Study protocols have been reviewed and approved by human subjects review boards at the Ministry of Health, Republic of Mozambique and the University of North Carolina at Chapel Hill. Deidentified study data will be deposited at https://osf.io/e7pvk/. TRIAL REGISTRATION NUMBER: ISRCTN86084138.

Study design and rationale for the PAASIM project: a matched cohort study on urban water supply improvements and infant enteric pathogen infection, gut microbiome development and health in Mozambique.

INTRODUCTION: Despite clear linkages between provision of clean water and improvements in child health, limited information exists about the health impacts of large water infrastructure improvements in low-income settings. Billions of dollars are spent annually to improve urban water supply, and rigorous evaluation of these improvements, especially targeting informal settlements, is critical to guide policy and investment strategies. Objective measures of infection and exposure to pathogens, and measures of gut function, are needed to understand the effectiveness and impact of water supply improvements. METHODS AND ANALYSIS: In the PAASIM study, we examine the impact of water system improvements on acute and chronic health outcomes in children in a low-income urban area of Beira, Mozambique, comprising 62 sub-neighbourhoods and ~26 300 households. This prospective matched cohort study follows 548 mother-child dyads from late pregnancy through 12 months of age. Primary outcomes include measures of enteric pathogen infections, gut microbiome composition and source drinking water microbiological quality, measured at the child's 12-month visit. Additional outcomes include diarrhoea prevalence, child growth, previous enteric pathogen exposure, child mortality and various measures of water access and quality. Our analyses will compare (1) subjects living in sub-neighbourhoods with the improved water to those living in sub-neighbourhoods without these improvements; and (2) subjects with household water connections on their premises to those without such a connection. This study will provide critical information to understand how to optimise investments for improving child health, filling the information gap about the impact of piped water provision to low-income urban households, using novel gastrointestinal disease outcomes. ETHICS AND DISSEMINATION: This study was approved by the Emory University Institutional Review Board and the National Bio-Ethics Committee for Health in Mozambique. The pre-analysis plan is published on the Open Science Framework platform (https://osf.io/4rkn6/). Results will be shared with relevant stakeholders locally, and through publications.