Benefits and Costs of a Community-Led Total Sanitation Intervention in Rural Ethiopia-A Trial-Based ex post Economic Evaluation

We estimated the costs and benefits of a community-led total sanitation (CLTS) intervention using the empirical results from a cluster-randomized controlled trial in rural Ethiopia. We modelled benefits and costs of the intervention over 10 years, as compared to an existing local government program. Health benefits were estimated as the value of averted mortality due to diarrheal disease and the cost of illness arising from averted diarrheal morbidity. We also estimated the value of time savings from avoided open defecation and use of neighbours' latrines. Intervention delivery costs were estimated top-down based on financial records, while recurrent costs were estimated bottom-up from trial data. We explored methodological and parameter uncertainty using one-way and probabilistic sensitivity analyses. Avoided mortality accounted for 58% of total benefits, followed by time savings from increased access to household latrines. The base case benefit-cost ratio was 3.7 (95% CI: 1.9-5.4) and the net present value was Int'l $1,193,786 (95% CI: 406,017-1,977,960). The sources of the largest uncertainty in one-way sensitivity analyses were the effect of the CLTS intervention and the assumed lifespan of an improved latrine. Our results suggest that CLTS interventions can yield favourable economic returns, particularly if follow-up after the triggering is implemented intensively and uptake of improved latrines is achieved (as opposed to unimproved).

Evaluating perfluorooctanesulfonate oxidation in permanganate systems

Permanganate (PM) has shown to be able to oxidize a range of organic contaminants including perfluorooctane sulfonate (PFOS). However, mechanisms of PFOS removal by PM have been questioned. To provide clarity to what may be happening to PFOS in PM systems, here we evaluated the ability of PM on PFOS destruction by conducting studies similar to previous studies that reported PFOS destruction which included PM solutions and PM combined with persulfate (PS). We also evaluated if addition of various soluble catalysts could enhance PM's potential to breakdown PFOS. We observed no PFOS destruction by PM. We also show that the F^- and SO₄^2- generation reported in a published study as evidence that PM was breaking bonds in PFOS were found below or not significantly higher than reported limits of quantitation and that SO₄^2- impurities in technical PM approach the reported SO₄^2- levels. For PM-PS systems, heterogeneous PFOS distribution was observed when subsampling reaction vessels at different depths and "salting-out" of PFOS was evident. In addition, subsequent sonication and filtering of the samples led to the apparent disappearance of most of the PFOS, which was an artifact arising from the behavior of PFOS aggregates or potential hemi-micelle formation. Given these findings, addition of salts may have application for collecting or concentrating PFOS and other PFAAs in a remediation or water treatment strategy.

Impact of an intervention to improve pit latrine emptying practices in low income urban neighborhoods of Maputo, Mozambique

Safe fecal sludge management (FSM) – the hygienic emptying, transport, and treatment for reuse or disposal of fecal sludge – is an essential part of safely managed sanitation, especially in towns and cities in low- and middle-income countries with limited sewer coverage. The need for safe and affordable FSM services has become more acute as cities grow and densify. Hygienic pit-emptying uses equipment that limits direct human exposure with fecal sludge and hygienic transport conveys fecal sludge offsite for treatment. We evaluated whether a program of on-site sanitation infrastructure upgrades and FSM capacity development in urban Maputo, Mozambique resulted in more hygienic pit-emptying and safe transportation of fecal sludge. We compared reported emptying practices among multi-household compounds receiving sanitation upgrades with control compounds, both from the Maputo Sanitation (MapSan) trial at 24–36 months after the intervention. Intervention compounds (comprising 1–40 households, median = 3) received a subsidized pour-flush latrine to septic tank system that replaced an existing shared latrine; control compounds continued using existing shared latrines. We surveyed compound residents and analyzed available municipal data on FSM in the city. Due to the recent construction of the intervention, emptying was more frequent in control compounds: 5.6% (15/270) of intervention compounds and 30% (74/247) of controls had emptied their on-site sanitation system in the previous year. Among those compounds which had emptied a sanitation facility in the previous year, intervention compounds were 3.8 (95% CI: 1.4, 10) times more likely to have to done so hygienically. Results suggest that the construction of subsidized pour-flush sanitation systems increased hygienic emptying of fecal sludge in this setting. Further gains in hygienic emptying in urban Maputo may be limited by affordability and physical accessibility.

Improving the use of intravenous antihypertensive medications in the hospital setting: a quality improvement initiative for patient safety

Intravenous (IV) hydralazine, enalapril and labetalol are oftentimes used without indication for the treatment of asymptomatic hypertension in the hospital setting and have been shown to have substantial adverse effects that are associated with increased morbidity and mortality, as well as longer length of stay. Their use is also associated with greater monetary costs. In this project, we studied the frequency of use and consequences of these medications before and after a series of education cycles which clarified when and when not to use intravenous antihypertensives (IVAHs). Our initial aim was to decrease the unindicated use of IVAH by at least 25% in the setting of asymptomatic hypertension in our community hospital within a 1-year period after introducing education on the topic. Multidisciplinary involvement throughout three Plan-Do-Study-Act (PDSA) cycles yielded favourable results. We focused on education towards a hospital-wide knowledge gap stemming from a lack of guidelines regarding the treatment of asymptomatic hypertension, as well as the guideline indications for IVAH. After three cycles of education targeting different groups, the unindicated use of IVAH fell by a total of 66%, decreasing patient exposure by approximately 248 cases over the total course of the study and ultimately, yielding a 52% increase in patient safety. Secondary outcome included a reduction in cost. It was noted that IV drugs cost more than their oral counterparts. The culture change in switching away from IVAH unless otherwise indicated was driven by repetitive education and group discussion to close the gap created by a lack of guidelines.

A localized sanitation status index as a proxy for fecal contamination in urban Maputo, Mozambique

Sanitary surveys are used in low- and middle-income countries to assess water, sanitation, and hygiene conditions, but have rarely been compared with direct measures of environmental fecal contamination. We conducted a cross-sectional assessment of sanitary conditions and E. coli counts in soils and on surfaces of compounds (household clusters) in low-income neighborhoods of Maputo, Mozambique. We adapted the World Bank's Urban Sanitation Status Index to implement a sanitary survey tool specifically for compounds: a Localized Sanitation Status Index (LSSI) ranging from zero (poor sanitary conditions) to one (better sanitary conditions) calculated from 20 variables that characterized local sanitary conditions. We measured the variation in the LSSI with E. coli counts in soil (nine locations/compound) and surface swabs (seven locations/compound) in 80 compounds to assess reliability. Multivariable regression indicated that a ten-percentage point increase in LSSI was associated with 0.05 (95% CI: 0.00, 0.11) log10 fewer E. coli/dry gram in courtyard soil. Overall, the LSSI may be associated with fecal contamination in compound soil; however, the differences detected may not be meaningful in terms of public health hazards.

Machine Learning Assisted Discovery of Novel Predictive Lab Tests Using Electronic Health Record Data

Epidemiological studies identifying biological markers of disease state are valuable, but can be time-consuming, expensive, and require extensive intuition and expertise. Furthermore, not all hypothesized markers will be borne out in a study, suggesting that higher quality initial hypotheses are crucial. In this work, we propose a high-throughput pipeline to produce a ranked list of high-quality hypothesized marker laboratory tests for diagnoses. Our pipeline generates a large number of candidate lab-diagnosis hypotheses derived from machine learning models, filters and ranks them according to their potential novelty using text mining, and corroborate final hypotheses with logistic regression analysis. We test our approach on a large electronic health record dataset and the PubMed corpus, and find several promising candidate hypotheses.

Factors Associated with Water Service Continuity for the Rural Populations of Bangladesh, Pakistan, Ethiopia, and Mozambique

Access to continuous water supply is key for improving health and economic outcomes in rural areas of low- and middle-income countries, but the factors associated with continuous water access in these areas have not been well-characterized. We surveyed 4786 households for evidence of technical, financial, institutional, social, and environmental predictors of rural water service continuity (WSC), defined as the percentage of the year that water is available from a source. Multiple imputed fractional logistic regression models that account for the survey design were used to assess operational risks to WSC for piped supply, tube wells, boreholes, springs, dug wells, and surface water for the rural populations of Bangladesh, Pakistan, Ethiopia, and Mozambique. Multivariable regressions indicate that households using multiple water sources were associated with lower WSC in Bangladesh, Pakistan, and Mozambique. However, the possibility must be considered that households may use more than one water source because services are intermittent. Water scarcity and drought were largely unassociated with WSC, suggesting that service interruptions may not be primarily due to physical water resource constraints. Consistent findings across countries may have broader relevance for meeting established targets for service availability as well as human health.

SUN-LB034 A Rare Cause of Hyperinsulinemic Hypoglycemia in Adulthood: A Case Report and Review of the Literature

Introduction: Post-prandial hypoglycaemia (PPH) after consumption of protein is a vanishingly rare condition. Congenital hyperinsulinism is the most common cause of persistent hypoglycemia in infants and children, although it is uncommon to be diagnosed in adulthood. Dominant activation of glutamate dehydrogenase, encoded for by the GLUD1 gene, causes the hyperinsulinemia/hyperammonemia syndrome (HHS). Within a family known to be affected by HHS, the first presentation in adulthood, is intriguing. Clinical case: A 32-year old male presented with new-onset generalised non-convulsive seizures and family history of genetically proven HHS in his mother, two siblings and two of their offspring. A heterozygous missense mutation (R269H) in exon 7 of the GLUD1 gene was identified several years ago in this family. Our patient was screened clinically for hypoglycemia in childhood, but he never underwent genetic testing, as he was not considered affected. Affected family members developed confusion and hypoglycaemia following high-protein meals, which was reversed with glucose and limiting protein intake, lessened further attacks. Our patient’s school performance was poor and described feeling unwell after eating large protein meals. He was fully orientated, but his mini-mental state examination was impaired at 21/30. He was hyper-reflexic with spreading of ankle and crossed adductor reflexes. Considering his family history, we performed continuous glucose monitoring for 14 days, revealing several post-prandial and fasting hypoglycaemic episodes (as low as 1.8 mmol/L) and an HbA1c of 3.5%. HHS was proven (serum ammonia 70 µmol/L; normal less than 35 µmol/L) and genetic analysis revealed an identical mutation to the aforementioned. Diazoxide was titrated to abrogate hypoglycaemia. Genetic screening of the remaining family members will be undertaken. Clinical lessons: Among causes of PPH, HHS is rare. Missed diagnoses can have profound neurological and cognitive consequences. The intrafamilial variability is demonstrable however; it is likely that HHS was missed in our patient’s initial presentation in childhood, as seizures and intellectual disability in adulthood are exceptionally rare complications of this condition. It demonstrates that it is critical to perform genetic testing on all members of an affected family, even in those asymptomatic. Genetic diagnoses of PPH are rarely made in adulthood, as there is often a low diagnostic suspicion at such a late presentation. References:1. K. E. Snider, S. Becker, L. Boyajian et al; Genotype and Phenotype Correlations in 417 Children With Congenital Hyperinsulinism; J Clin Endocrinol Metab, February 2013, 98(2):E355-E3632. Charles A. Stanley; Hyperinsulinism/hyperammonemia syndrome: insights into the regulatory role of glutamate dehydrogenase in ammonia metabolism; Molecular Genetics and Metabolism81 (2004) S45-S51 Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Detectable prednisolone is delayed in pericardial fluid, compared with plasma of patients with tuberculous pericarditis: A pilot study

Background

In patients with tuberculous pericarditis [TBP] adjunctive prednisolone reduces the incidence of constrictive pericarditis. It is unknown whether prednisolone permeates adequately into pericardial fluid. Drug measurements in pericardial fluid require invasive procedures, and thus less invasive methods are needed to perform full pharmacokinetic characterization of prednisolone in large numbers of patients. We sought to evaluate the relationship between prednisolone concentrations in pericardial fluid, plasma, and saliva.

Methods

Plasma, pericardial fluid, and saliva samples were collected at 7 time points from TBP patients randomized to 120 mg prednisolone or placebo. Compartmental pharmacokinetic parameters, peak concentration [C_max], and 0-24 h area under the concentration-time curve [AUC_0-24] were identified in plasma, saliva and pericardial fluid.

Results

There were five patients each in the prednisolone and placebo groups. Prednisolone concentrations were best described using a one compartment model. The absorption half-life into plasma was 1 h, while that into pericardial fluid was 9.4 h, which led to a median time-to-maximum concentration in plasma of 2.0 h versus 5.0 h in pericardial fluid [p = 0.048]. The concentration-time profiles in pericardial fluid versus plasma exhibited system hysteresis. The pericardial fluid-to-plasma C_max peak concentration ratio was 0.28 (p = 0.032), while the AUC_0-24 ratio was 0.793. The concentration-time profiles in saliva had a similar shape to those in plasma, but the saliva-to-plasma C_max was 0.59 [p = 0.032].

Conclusion

The prednisolone AUC_0-24 achieved in pericardial fluid approximates that in plasma, but the C_max is low due to delayed absorption. Saliva can be used as surrogate sampling site for pericardial fluid prednisolone.

Single-Neuron Correlates of Error Monitoring and Post-Error Adjustments in Human Medial Frontal Cortex

Humans can self-monitor errors without explicit feedback, resulting in behavioral adjustments on subsequent trials such as post-error slowing (PES). The error-related negativity (ERN) is a well-established macroscopic scalp EEG correlate of error self-monitoring, but its neural origins and relationship to PES remain unknown. We recorded in the frontal cortex of patients performing a Stroop task and found neurons that track self-monitored errors and error history in dorsal anterior cingulate cortex (dACC) and pre-supplementary motor area (pre-SMA). Both the intracranial ERN (iERN) and error neuron responses appeared first in pre-SMA, and ∼50 ms later in dACC. Error neuron responses were correlated with iERN amplitude on individual trials. In dACC, such error neuron-iERN synchrony and responses of error-history neurons predicted the magnitude of PES. These data reveal a human single-neuron correlate of the ERN and suggest that dACC synthesizes error information to recruit behavioral control through coordinated neural activity.

Dataset of human medial temporal lobe single neuron activity during declarative memory encoding and recognition

We present a dataset of 1,576 single neurons recorded from the human amygdala and hippocampus in 65 sessions from 42 patients undergoing intracranial monitoring for localization of epileptic seizures. Subjects performed a recognition memory task with pictures as stimuli. Subjects were asked to identify whether they had seen a particular image the first time ('new') or second time ('old') on a 1-6 confidence scale. This comprehensive dataset includes the spike times of all neurons and their extracellular waveforms, behavior, electrode locations determined from post-operative MRI scans, demographics, and the stimuli shown. As technical validation, we provide spike sorting quality metrics and assessment of tuning of cells to verify the presence of visually-and memory selective cells. We also provide analysis code that reproduces key scientific findings published previously on a smaller version of this dataset. Together, this large dataset will facilitate the investigation of the neural mechanism of declarative memory by providing a substantial number of hard to obtain human single-neuron recordings during a well characterized behavioral task.

AIDS-Defining Illnesses at Initial Diagnosis of HIV in a Large Guatemalan Cohort

Background

Anecdotal evidence suggests that a high proportion of patients diagnosed with HIV in Guatemala present with AIDS. There remain limited data on the epidemiology of AIDS-defining illnesses (ADIs) in Central America.

Methods

We conducted a retrospective cohort study of all patients living with HIV at the largest HIV clinic in Guatemala. Charts were analyzed for clinical and demographic data. Presence of an ADI was assessed by US Centers for Disease Control definitions; patients who presented with an ADI were compared with those without ADI using descriptive statistics.

Results

Of 3686 patients living with HIV, 931 (25.3%) had an ADI at HIV diagnosis, 748 (80.3%) of whom had CD4 counts lower than 200 cells/mm³. Those with ADIs were more likely to be male (67.5% vs 54.6%; P < .0001) and heterosexual (89.4% vs 85.0%; P = .005). The most common ADIs were Mycobacterium tuberculosis (55.0%), Pneumocystis jirovecii pneumonia (13.7%), esophageal candidiasis (13.4%), and histoplasmosis (11.4%). Histoplasmosis and HIV wasting syndrome were both more common among rural patients.

Conclusions

In this large Guatemalan cohort of patients currently living with HIV, a significant portion presented with an ADI. These data inform the most common ADIs diagnosed among survivors, show that histoplasmosis is more commonly diagnosed in rural patients, and suggest that HIV wasting syndrome may reflect missed histoplasmosis diagnoses.

Estimating Infection Risks and the Global Burden of Diarrheal Disease Attributable to Intermittent Water Supply Using QMRA

Intermittent water supply (IWS) is prevalent throughout low and middle-income countries. IWS is associated with increased microbial contamination and potentially elevated risk of waterborne illness. We used existing data sets to estimate the population exposed to IWS, assess the probability of infection using quantitative microbial risk assessment, and calculate the subsequent burden of diarrheal disease attributable to consuming fecally contaminated tap water from an IWS. We used reference pathogens Campylobacter, Cryptosporidium, and rotavirus as conservative risk proxies for infections via bacteria, protozoa, and viruses, respectively. Results indicate that the median daily risk of infection is an estimated 1 in 23 500 for Campylobacter, 1 in 5 050 000 for Cryptosporidium, and 1 in 118 000 for rotavirus. Based on these risks, IWS may account for 17.2 million infections causing 4.52 million cases of diarrhea, 109 000 diarrheal DALYs, and 1560 deaths each year. The burden of diarrheal disease associated with IWS likely exceeds the WHO health-based normative guideline for drinking water of 10^-6 DALYs per person per year. Our results underscore the importance water safety management in water supplies and the potential benefits of point-of-use treatment to mitigate risks.

Awareness and attitudes of pre-exposure prophylaxis for HIV prevention among physicians in Guatemala: Implications for country-wide implementation

INTRODUCTION

HIV continues to be a major health concern with approximately 2.1 million new infections occurring worldwide in 2015. In Central America, Guatemala had the highest incident number of HIV infections (3,700) in 2015. Antiretroviral pre-exposure prophylaxis (PrEP) was recently recommended by the World Health Organization (WHO) as an efficacious intervention to prevent HIV transmission. PrEP implementation efforts are underway in Guatemala and success will require providers that are knowledgeable and willing to prescribe PrEP. We sought to explore current PrEP awareness and prescribing attitudes among Guatemalan physicians in order to inform future PrEP implementation efforts.

METHODS

We conducted a cross-sectional survey of adult internal medicine physicians at the main teaching hospital in Guatemala City in March 2015. The survey included demographics, medical specialty, years of HIV patient care, PrEP awareness, willingness to prescribe PrEP, previous experience with post-exposure prophylaxis, and concerns about PrEP. The primary outcome was willingness to prescribe PrEP, which was assessed using a 5-point Likert scale for different at-risk population scenarios. Univariate and multivariate logistic regression was performed to identify predictors for willingness to prescribe PrEP.

RESULTS

Eighty-seven physicians completed the survey; 66% were male, 64% were internal medicine residency trainees, and 10% were infectious disease (ID) specialists. Sixty-nine percent of physicians were PrEP aware, of which 9% had previously prescribed PrEP. Most (87%) of respondents were willing to prescribe PrEP to men who have sex with men (MSM), sex workers, injection drug users, or HIV-uninfected persons having known HIV-positive sexual partners. Concerns regarding PrEP included development of resistance (92%), risk compensation (90%), and cost (64%). Univariate logistic regression showed that younger age, being a resident trainee, and being a non-ID specialist were significant predictors for willingness to prescribe PrEP. In multivariate logistic regression, being a non-ID specialist was a significant predictor.

CONCLUSIONS

Guatemalan physicians at an urban public hospital were PrEP aware and willing to prescribe, but few have actually done so yet. Future education programs should address the concerns identified, including the low potential for the development of antiretroviral resistance. These findings can aid PrEP implementation efforts in Guatemala.

Nanomolar oligomerization and selective co-aggregation of α-synuclein pathogenic mutants revealed by single-molecule fluorescence

Protein aggregation is a hallmark of many neurodegenerative diseases, notably Alzheimer's and Parkinson's disease. Parkinson's disease is characterized by the presence of Lewy bodies, abnormal aggregates mainly composed of α-synuclein. Moreover, cases of familial Parkinson's disease have been linked to mutations in α-synuclein. In this study, we compared the behavior of wild-type (WT) α-synuclein and five of its pathological mutants (A30P, E46K, H50Q, G51D and A53T). To this end, single-molecule fluorescence detection was coupled to cell-free protein expression to measure precisely the oligomerization of proteins without purification, denaturation or labelling steps. In these conditions, we could detect the formation of oligomeric and pre-fibrillar species at very short time scale and low micromolar concentrations. The pathogenic mutants surprisingly segregated into two classes: one group forming large aggregates and fibrils while the other tending to form mostly oligomers. Strikingly, co-expression experiments reveal that members from the different groups do not generally interact with each other, both at the fibril and monomer levels. Together, this data paints a completely different picture of α-synuclein aggregation, with two possible pathways leading to the development of fibrils.