Replacement of water and electrolyte losses in cholera by an oral glucose-electrolyte solution

Genetic approach toward linkage of Iran 2012-2016 cholera outbreaks with 7th pandemic Vibrio cholerae

Vibrio cholerae, as a natural inhabitant of the marine environment is among the world-leading causes of diarrheal diseases. The present study aimed to investigate the genetic relatedness of Iran 2012-2016 V. cholerae outbreaks with 7th pandemic cholera and to further characterize the non-ST69/non-ST75 sequence types strains by whole-genome sequencing (WGS).Twenty V. cholerae isolates related to 2012, 2013, 2015 and 2016 cholera outbreaks were studied by two genotyping methods - Pulsed-field Gel Electrophoresis (PFGE) and Multi-locus Sequence Typing (MLST)-and by antimicrobial susceptibility testing. Seven sequence types (STs) and sixteen pulsotypes were detected. Sequence type 69 was the most abundant ST confirming that most (65%, 13/20) of the studied isolates collected in Iran between 2012 and 2016 belonged to the 7th pandemic clone. All these ST69 isolates (except two) exhibited similar pulsotypes. ST75 was the second most abundant ST. It was identified in 2015 and 2016. ST438, ST178, ST579 and STs of 983 and 984 (as newfound STs) each were only detected in one isolate. All strains collected in 2016 appeared as distinct STs and pulsotypes indicative of probable different originations. All ST69 strains were resistant to nalidixic acid. Moreover, resistance to nalidixic acid, trimethoprim-sulfamethoxazole and tetracycline was only observed in strains of ST69. These properties propose the ST69 as a unique genotype derived from a separate lineage with distinct resistance properties. The circulation of V. cholerae ST69 and its traits in recent years in Iran proposes the 7th pandemic strains as the ongoing causes of cholera outbreaks in this country, although the role of ST75 as the probable upcoming dominant ST should not be ignored.Genomic analysis of non-ST69/non-ST75 strains in this study showed ST579 is the most similar ST type to 7th pandemic sequence types, due to the presence of wild type-El Tor sequences of tcpA and VC-1319, VC-1320, VC-1577, VC-1578 genes (responsible for polymyxin resistance in El Tor biotype), the traits of rstC of RS1 phage in one strain of this ST type and the presence of VPI-1 and VSP-I islands in ST579 and ST178 strains. In silico analysis showed no significant presence of resistance genes/cassettes/plasmids within non-ST69/non-ST75 strains genomes. Overall, these data indicate the higher susceptibility of V. cholerae non-ST69/non-ST75 strains in comparison with more ubiquitous and more circulating ST69 and ST75 strains.In conclusion, the occurrence of small outbreaks and sporadic cholera cases due to V. cholerae ST69 in recent years in Iran shows the 7th pandemic strains as the persistent causes of cholera outbreaks in this country, although the role of ST75 as the second most contributed ST should not be ignored. The occurrence of non-ST69/non-ST75 sequence types with some virulence factors characteristics in border provinces in recent years is noteworthy, and further studies together with surveillance efforts are expected to determine their likely route of transport.

The magnitude of oral rehydration salt utilization in diarrhea hot spot regions of Ethiopia and its associated factors among under-five children: A multilevel analysis based on Bayesian approach

Background

Diarrhea leads the children to severe dehydration or death as a result of the loss of water and electrolytes (namely, potassium, chloride, sodium, and bicarbonate). To compensate for the losses, ORS is given to children who experienced diarrhea.

Objective

To estimate the magnitude of ORS utilization in diarrhea hotspot regions of Ethiopia and to assess its associated factors among under-five children.

Methods

To conduct this study, we used the 2016 Ethiopian demographic and health survey data. A total of 1,079 weighted sample children were selected. Each sample was selected randomly. Then, to identify factors associated with ORS utilization in diarrhea hotspot regions of Ethiopia, a multilevel analysis based on the Bayesian approach was applied. Finally, the credible interval of AOR that does not include 1 was considered statistically significant.

Results

The magnitude of ORS utilization for children in diarrhea hotspot regions of Ethiopia was 28%. Being urban resident (AOR = 1.92; 95% CrI: 1.13-3.3), woman household head (AOR = 2.11; 95% CrI: 1.3-3.9), having higher educational level (AOR = 1.52; 95% CrI: 1.04-2.22), member of health insurance (AOR = 1.73; 95% CrI: 1.14-2.43), and being exposed for media (AOR = 1.43; 95% CrI: 1.18-2.5) increases ORS utilization for diarrhea management.

Conclusion

Residence, educational level, health insurance, and media exposure were the factors of ORS utilization. So, to increase the practice of ORS utilization for diarrhea management in Ethiopia, the Ministry of Health and the Government of Ethiopia should consider those factors when they design diarrhea prevention and control strategies.

Determinants of oral rehydration salt utilization among under-five children with diarrhea in Ethiopia: A multilevel mixed-effect analysis

BACKGROUND

Oral rehydration salt therapy is a critical intervention to reduce mortality and morbidity of children with diarrheal diseases. However, it remains underused in low- and middle-income countries. In Ethiopia, only less than half of children with diarrheal diseases were treated with oral rehydration salt solution. Therefore, the objective of this study was to identify the determinants of oral rehydration salt utilization among children with diarrhea in Ethiopia.

METHOD

A secondary data analysis was done using the 2016 Ethiopian Demographic and Health Survey. A weighted sample of 1227 children who had diarrhea in the last 2 weeks with their index mothers during the 5 years survey was included in the study. A multilevel mixed logistic regression model was fitted to identify factors associated with oral rehydration salt utilization. Finally, statistical significance was declared at p-value < 0.05.

RESULT

The overall prevalence of oral rehydration salt utilization for children with diarrhea was 29.5%. In this study, age of mother ⩾35 (adjusted odds ratio = 1.66, 95% confidence interval = 1.05, 2.64), mothers with formal education (adjusted odds ratio = 1.52, 95% confidence interval = 1.09, 2.11), media exposure (adjusted odds ratio = 1.72, 95% confidence interval = 1.25, 2.38), living in Metropolitan regions (Addis Ababa and Dire Dawa (adjusted odds ratio = 1.76, 95% confidence interval = 1.14, 2.69)), and small peripheral regions (Afar, Gambela, Somalia, Benishangul-Gumuz (adjusted odds ratio = 1.69, 95% confidence interval = 1.22, 2.34)) were associated with higher odd of oral rehydration salt utilization for children with diarrhea.

CONCLUSION

The study concludes that the age of mothers, educational status of the mother, media exposure, and regions of mothers were determinants of oral rehydration salt utilization for children with diarrhea. Therefore, media advertising regarding diarrhea management should be scaled up to increase oral rehydration salt utilization for children with diarrhea. Special attention to socio-cultural constraints or beliefs regarding diarrhea management should be given to mothers from large to center (Tigray, Amhara, Oromia, Southern Nations Nationalities, and People's Region, and Harari) regions.

The Cost-Effectiveness of Community Health Workers Delivering Free Diarrhea Treatment: Evidence from Uganda

Community health workers (CHWs) are a vital part of the health infrastructure in Uganda and in many other low- and middle-income countries. While the need for CHWs is clear, it is less clear how they should dispense health products to maximize the health benefits to their community. In this study, we assess the cost-effectiveness of several competing CHW distribution strategies in the context of treatment for child diarrhea. We used data from a 4-armed cluster-randomized controlled trial to assess the cost-effectiveness of 1) free distribution of oral rehydration salts (ORS) via home deliveries prior to diarrhea onset (free delivery arm), 2) free distribution via vouchers where households retrieved the treatment from a central location (voucher arm), 3) a door-to-door sales model (home sales arm), and 4) a control arm where CHWs carried out their activities as normal. We assessed the cost-effectiveness from the implementor's perspective and a societal perspective, in terms of cost per case treated with ORS and cost per disability adjusted life-year (DALY) averted. Free delivery was the most effective strategy and the cheapest from a societal perspective. Although implementor costs were highest in this arm, cost savings comes from households using fewer resources to seek treatment outside the home (transport, doctor fees, and treatment costs). From the implementors' perspective, free delivery costs $2.19 per additional case treated and $56 per DALY averted relative to the control. Free delivery was also extremely cost-effective relative to home sales and vouchers but there was a large degree of uncertainty around the comparison with vouchers. Free distribution of ORS by CHWs prior to diarrhea onset is extremely cost-effective compared to other CHW distribution models. Implementers of CHW programs should consider free home delivery of ORS.

Mapping geographical inequalities in oral rehydration therapy coverage in low-income and middle-income countries, 2000-17

BACKGROUND

Oral rehydration solution (ORS) is a form of oral rehydration therapy (ORT) for diarrhoea that has the potential to drastically reduce child mortality; yet, according to UNICEF estimates, less than half of children younger than 5 years with diarrhoea in low-income and middle-income countries (LMICs) received ORS in 2016. A variety of recommended home fluids (RHF) exist as alternative forms of ORT; however, it is unclear whether RHF prevent child mortality. Previous studies have shown considerable variation between countries in ORS and RHF use, but subnational variation is unknown. This study aims to produce high-resolution geospatial estimates of relative and absolute coverage of ORS, RHF, and ORT (use of either ORS or RHF) in LMICs.

METHODS

We used a Bayesian geostatistical model including 15 spatial covariates and data from 385 household surveys across 94 LMICs to estimate annual proportions of children younger than 5 years of age with diarrhoea who received ORS or RHF (or both) on continuous continent-wide surfaces in 2000-17, and aggregated results to policy-relevant administrative units. Additionally, we analysed geographical inequality in coverage across administrative units and estimated the number of diarrhoeal deaths averted by increased coverage over the study period. Uncertainty in the mean coverage estimates was calculated by taking 250 draws from the posterior joint distribution of the model and creating uncertainty intervals (UIs) with the 2·5th and 97·5th percentiles of those 250 draws.

FINDINGS

While ORS use among children with diarrhoea increased in some countries from 2000 to 2017, coverage remained below 50% in the majority (62·6%; 12 417 of 19 823) of second administrative-level units and an estimated 6 519 000 children (95% UI 5 254 000-7 733 000) with diarrhoea were not treated with any form of ORT in 2017. Increases in ORS use corresponded with declines in RHF in many locations, resulting in relatively constant overall ORT coverage from 2000 to 2017. Although ORS was uniformly distributed subnationally in some countries, within-country geographical inequalities persisted in others; 11 countries had at least a 50% difference in one of their units compared with the country mean. Increases in ORS use over time were correlated with declines in RHF use and in diarrhoeal mortality in many locations, and an estimated 52 230 diarrhoeal deaths (36 910-68 860) were averted by scaling up of ORS coverage between 2000 and 2017. Finally, we identified key subnational areas in Colombia, Nigeria, and Sudan as examples of where diarrhoeal mortality remains higher than average, while ORS coverage remains lower than average.

INTERPRETATION

To our knowledge, this study is the first to produce and map subnational estimates of ORS, RHF, and ORT coverage and attributable child diarrhoeal deaths across LMICs from 2000 to 2017, allowing for tracking progress over time. Our novel results, combined with detailed subnational estimates of diarrhoeal morbidity and mortality, can support subnational needs assessments aimed at furthering policy makers' understanding of within-country disparities. Over 50 years after the discovery that led to this simple, cheap, and life-saving therapy, large gains in reducing mortality could still be made by reducing geographical inequalities in ORS coverage.

FUNDING

Bill & Melinda Gates Foundation.

Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000-17: analysis for the Global Burden of Disease Study 2017

BACKGROUND

Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea.

METHODS

We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates.

FINDINGS

The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1-65·8), 17·4% (7·7-28·4), and 59·5% (34·2-86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage.

INTERPRETATION

By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health.

FUNDING

Bill & Melinda Gates Foundation.

The role of price and convenience in use of oral rehydration salts to treat child diarrhea: A cluster randomized trial in Uganda

BACKGROUND

Over half a million children die each year of diarrheal illness, although nearly all deaths could be prevented with oral rehydration salts (ORS). The literature on ORS documents both impressive health benefits and persistent underuse. At the same time, little is known about why ORS is underused and what can be done to increase use. We hypothesized that price and inconvenience are important barriers to ORS use and tested whether eliminating financial and access constraints increases ORS coverage.

METHODS AND FINDINGS

In July of 2016, we recruited 118 community health workers (CHWs; representing 10,384 households) in Central and Eastern Uganda to participate in the study. Study villages were predominantly peri-urban, and most caretakers had no more than primary school education. In March of 2017, we randomized CHWs to one of four methods of ORS distribution: (1) free delivery of ORS prior to illness (free and convenient); (2) home sales of ORS prior to illness (convenient only); (3) free ORS upon retrieval using voucher (free only); and (4) status quo CHW distribution, where ORS is sold and not delivered (control). CHWs offered zinc supplements in addition to ORS in all treatment arms (free in groups 1 and 3 and for sale in group 2), following international treatment guidelines. We used household surveys to measure ORS (primary outcome) and ORS + zinc use 4 weeks after the interventions began (between April and May 2017). We assessed impact using an intention-to-treat (ITT) framework. During follow-up, we identified 2,363 child cases of diarrhea within 4 weeks of the survey (584 in free and convenient [25.6% of households], 527 in convenient only [26.1% of households], 648 in free only [26.8% of households], and 597 in control [28.5% of households]). The share of cases treated with ORS was 77% (448/584) in the free and convenient group, 64% (340/527) in the convenient only group, 74% (447/648) in the free only group, and 56% (335/597) in the control group. After adjusting for potential confounders, instructing CHWs to provide free and convenient distribution increased ORS coverage by 19 percentage points relative to the control group (95% CI 13-26; P < 0.001), 12 percentage points relative to convenient only (95% CI 6-18; P < 0.001), and 2 percentage points (not significant) relative to free only (95% CI -4 to 8; P = 0.38). Effect sizes were similar, but more pronounced, for the use of both ORS and zinc. Limitations include short follow-up period, self-reported outcomes, and limited generalizability.

CONCLUSIONS

Most caretakers of children with diarrhea in low-income countries seek care in the private sector where they are required to pay for ORS. However, our results suggest that price is an important barrier to ORS use and that switching to free distribution by CHWs substantially increases ORS coverage. Switching to free distribution is low-cost, easily scalable, and could substantially reduce child mortality. Convenience was not important in this context.

TRIAL REGISTRATION

Trial registry number AEARCTR-0001288.

Treatment of severe cholera: a review of strategies to reduce stool output and volumes of rehydration fluid

Background

Severe cholera is a life-threatening illness of hypovolemic shock and metabolic acidosis due to rapid and profuse diarrheal fluid loss. Emergency life-saving therapy is i.v. saline, optionally supplemented with potassium and alkali to correct the fluid deficit, potassium losses and acidosis. After this initial rehydration, for the next 2 days ongoing stool losses are replaced with oral rehydration solution (ORS), which contains sodium chloride, potassium and alkali together with glucose or rice powder as a source of glucose to serve as a carrier for sodium.

Results

In actual field trials, antibiotics are given to reduce fluid requirements, but large volumes averaging about 7 liters of i.v. fluid followed by about 14 liters of ORS have been given to adult patients. Disturbing trends during therapy have included overhydration, hyponatremia and polyuria.

Conclusions

It is suggested that stool output and fluid requirements could be reduced, if borne out in future research, by avoiding overhydration by restricting ORS intake to match stool output and promoting intestinal reabsorption of luminal fluid by early introduction of glucose without salts into the intestine, more gradual correction of dehydration, giving mineralocorticoid and vasopressin, and infusing glucose or short-chain fatty acids into the proximal colon.

From Treating Childhood Malnutrition to Public Health Nutrition

BACKGROUND

This analysis sets out an overview of an IUNS presentation of a European clinician's assessment of the challenges of coping with immediate critical clinical problems and how to use metabolic and a mechanistic understanding of disease when developing nutritional policies.

SUMMARY

Critically ill malnourished children prove very sensitive to both mineral and general nutritional overload, but after careful metabolic control they can cope with a high-quality, energy-rich diet provided their initial lactase deficiency and intestinal atrophy are taken into account. Detailed intestinal perfusion studies also showed that gastroenteritis can be combatted by multiple frequent glucose/saline feeds, which has saved millions of lives. However, persisting pancreatic islet cell damage may explain our findings of pandemic rates of adult diabetes in Asia, the Middle East and Mexico and perhaps elsewhere including Africa and Latin America. These handicaps together with the magnitude of epigenetic changes emphasized the importance of a whole life course approach to nutritional policy making. Whole body calorimetric analyses of energy requirements allowed a complete revision of estimates for world food needs and detailed clinical experience showed the value of redefining stunting and wasting in childhood and the value of BMI for classifying appropriate adult weights, underweight and obesity. Lithium tracer studies of dietary salt sources should also dictate priorities in population salt-reduction strategies. Metabolic and clinical studies combined with meticulous measures of population dietary intakes now suggest the need for far more radical steps to lower the dietary goals for both free sugars and total dietary fat unencumbered by flawed cohort studies that neglect not only dietary errors but also the intrinsic inter-individual differences in metabolic responses to most nutrients. Key Messages: Detailed clinical and metabolic analyses of physiological responses combined with rigorous dietary and preferably biomarker of mechanistic pathways should underpin a new approach not only to clinical care but also to the development of more radical nutritional policies.

Rapid cessation of acute diarrhea using a novel solution of bioactive polyphenols: a randomized trial in Nicaraguan children

Goal. We assessed the effectiveness of bioactive polyphenols contained in solution (LX) to restore normal bowel function in pediatric patients with acute diarrhea. Background. While providing oral rehydration solution (ORS) is standard treatment for diarrhea in developing countries, plant-derived products have been shown to positively affect intestinal function. If a supplement to ORS resolves diarrhea more rapidly than ORS alone, it is an improvement to current care. Study. In a randomized, double-blind, placebo-controlled cross-over study, 61 pediatric patients with uncontrolled diarrhea were randomized to receive either ORS + LX on day 1 and then ORS + water on day 2 (study arm) or ORS + water on day 1 and then ORS + LX on day 2 (control arm). Time to resolution and number of bowel movements were recorded. Results. On day 1, the mean time to diarrhea resolution was 3.1 h (study arm) versus 9.2 h (control arm) (p = 0.002). In the study arm, 60% of patients had normal stool at their first bowel movement after consumption of the phenolic redoxigen solution (LX). On day 2, patients in the study arm continued to have normal stool while patients in the control arm achieved normal stool within 24 h after consuming the test solution. Patients in the control arm experienced a reduction in the mean number of bowel movements from day 1 to day 2 after consuming the test solution (p = 0.0001). No adverse events were observed. Conclusions. Significant decreases in bowel movement frequency and rapid normalization of stool consistency were observed with consumption of this novel solution.

Barriers to use of oral rehydration salts for child diarrhea in the private sector: evidence from India

Diarrhea is the second leading cause of child mortality in India. Most deaths are cheaply preventable with the use of oral rehydration salts (ORS), yet many health providers still fail to provide ORS to children seeking diarrheal care. In this study, we use survey data to assess whether children visiting private providers for diarrheal care were less likely to use ORS than those visiting public providers. Results suggest that children who visited private providers were 9.5 percentage points less likely to have used ORS than those who visited public providers (95% CI 5-14). We complimented these results with in-depth interviews of 21 public and 17 private doctors in Gujarat, India, assessing potential drivers of public-private disparities in ORS use. Interview results suggested that lack of direct medication dispensing in the private sector might be a key barrier to ORS use in the private sector.

Private sector provision of oral rehydration therapy for child diarrhea in sub-Saharan Africa

Although diarrheal mortality is cheaply preventable with oral rehydration therapy (ORT), over 700,000 children die of diarrhea annually and many health providers fail to treat diarrheal cases with ORT. Provision of ORT may differ between for-profit and public providers. This study used Demographic and Health Survey data from 19,059 children across 29 countries in sub-Saharan Africa from 2003 to 2011 to measure differences in child diarrhea treatment between private for-profit and public health providers. Differences in treatment provision were estimated using probit regression models controlling for key confounders. For-profit providers were 15% points less likely to provide ORT (95% confidence interval [CI] 13-17) than public providers and 12% points more likely to provide other treatments (95% CI 10-15). These disparities in ORT provision were more pronounced for poorer children in rural areas. As private healthcare in sub-Saharan Africa continues to expand, interventions to increase private sector provision of ORT should be explored.

Management strategies in the treatment of neonatal and pediatric gastroenteritis

Acute gastroenteritis, characterized by the onset of diarrhea with or without vomiting, continues to be a major cause of morbidity and mortality in children in mostly resource-constrained nations. Although generally a mild and self-limiting disease, gastroenteritis is one of the most common causes of hospitalization and is associated with a substantial disease burden. Worldwide, up to 40% of children aged less than 5 years with diarrhea are hospitalized with rotavirus. Also, some microorganisms have been found predominantly in resource-constrained nations, including Shigella spp, Vibrio cholerae, and the protozoan infections. Prevention remains essential, and the rotavirus vaccines have demonstrated good safety and efficacy profiles in large clinical trials. Because dehydration is the major complication associated with gastroenteritis, appropriate fluid management (oral or intravenous) is an effective and safe strategy for rehydration. Continuation of breastfeeding is strongly recommended. New treatments such as antiemetics (ondansetron), some antidiarrheal agents (racecadotril), and chemotherapeutic agents are often proposed, but not yet universally recommended. Probiotics, also known as "food supplement," seem to improve intestinal microbial balance, reducing the duration and the severity of acute infectious diarrhea. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition and the European Society of Paediatric Infectious Diseases guidelines make a stronger recommendation for the use of probiotics for the management of acute gastroenteritis, particularly those with documented efficacy such as Lactobacillus rhamnosus GG, Lactobacillus reuteri, and Saccharomyces boulardii. To date, the management of acute gastroenteritis has been based on the option of "doing the least": oral rehydration-solution administration, early refeeding, no testing, no unnecessary drugs.

The effect of oral rehydration solution and recommended home fluids on diarrhoea mortality

Background Most diarrhoeal deaths can be prevented through the prevention and treatment of dehydration. Oral rehydration solution (ORS) and recommended home fluids (RHFs) have been recommended since 1970s and 1980s to prevent and treat diarrhoeal dehydration. We sought to estimate the effects of these interventions on diarrhoea mortality in children aged <5 years.

Methods We conducted a systematic review to identify studies evaluating the efficacy and effectiveness of ORS and RHFs and abstracted study characteristics and outcome measures into standardized tables. We categorized the evidence by intervention and outcome, conducted meta-analyses for all outcomes with two or more data points and graded the quality of the evidence supporting each outcome. The CHERG Rules for Evidence Review were used to estimate the effectiveness of ORS and RHFs against diarrhoea mortality.

Results We identified 205 papers for abstraction, of which 157 were included in the meta-analyses of ORS outcomes and 12 were included in the meta-analyses of RHF outcomes. We estimated that ORS may prevent 93% of diarrhoea deaths.

Conclusions ORS is effective against diarrhoea mortality in home, community and facility settings; however, there is insufficient evidence to estimate the effectiveness of RHFs against diarrhoea mortality.

The Johns Hopkins Center for Global Health: transcending borders for world health

The causes and effects of many health problems, whether infectious, environmental, lifestyle related, or caused by manmade or natural disasters, are becoming increasingly global in nature. Integrated approaches to solving these problems require the expertise of large and diverse groups of health professionals, to design lifesaving research and to implement effective responses. The Johns Hopkins University public health, medical, and nursing communities have a history of leadership in both modern medicine and public health, and they have unparalleled human resources in the clinical, research, programmatic, policy, and educational domains, with an extensive network of international colleagues and collaborators. To best utilize these resources to have a positive impact on global health issues, the university created the Center for Global Health in 2006 to facilitate and coordinate the various international activities of the faculty and students in the field of global health. The center has seven specific initiatives aimed at educating students and facilitating the faculty's collaborative research: serving as a resource center for global health activities within the university; facilitating and coordinating topical areas of global research; promoting educational programs in global health; providing global health field training grants; granting global health scholarships; focusing on global health research and practice; and coordinating symposia, forums, and policy initiatives. The author elaborates on these initiatives and discusses challenges experienced in establishing the center, as well as evaluation methods for determining the center's success.

A legacy in 20th-century medicine: Robert Allan Phillips and the taming of cholera

The legacy of Captain Robert Allan Phillips (1906-1976) was to establish effective, evidence-based rehydration methods for the treatment of cholera. As a Navy Lieutenant at the Rockefeller Institute for Medical Research (New York, New York) during World War II, Phillips developed a field method for the rapid assessment of fluid loss in wounded servicemen. After the war, he championed the establishment of United States Naval Medical Research Unit (NAMRU)-3 (Cairo; 1946) and NAMRU-2 (Taipei; 1955), serving at the helm of both units. Phillips embarked on cholera studies during the 1947 Egyptian cholera epidemic and brought them to maturity at NAMRU-2 (1958-1965), elucidating the pathophysiologic derangements induced by cholera and developing highly efficacious methods of intravenous rehydration. His conception of a simpler cholera treatment was realized in the late 1960s with the development of glucose-based oral rehydration therapy, a monumental breakthrough to which many other investigators made vital contributions. Today, these simple advances have been integrated into everyday medical practice across the globe, saving millions of lives annually.

Infectious diarrhea in children

Infectious diarrhea in children remains an important cause of morbidity in North America with rotavirus, nontyphoidal salmonella, Campylobacter and Giardia being the predominant pathogens in children younger than 5 years. Knowledge of the epidemiology of the diarrheal illness in a community together with the clinical information are necessary when determining the extent of investigation. Oral rehydration remains the mainstay of therapy and antibiotics are reserved for specific clinical situations and infections.

Improving the palatability of oral rehydration solutions has implications for salt and water transport: a study in animal models

It is believed that improving the taste of oral rehydration solutions (ORSs) might lead to greater patient acceptability. A pilot trial showed that replacing glucose with sucrose and increasing the citrate concentration at the expense of chloride improves palatability. However, the transport implications of such modifications are not known. Three hypotonic experimental ORSs (Suc/cit-ORS, 211 mosmol/kg; Suc/Cl-ORS, 224 mosmol/kg; and Glu-ORS, 224 mosmol/kg) were compared with a standard European ORS (Euro-ORS, 265 mosmol/kg) by in vivo perfusion of entire rat small intestine in normal adult rats and rotavirus-infected neonates. All ORSs were of identical sodium, potassium, chloride, and citrate content except that in the Suc/cit-ORS, chloride was removed in favor of increased citrate, and the chloride concentration in Euro-ORS was higher than in the others. Suc/cit-ORS and Suc/Cl-ORS had glucose partially replaced by sucrose while Glu-ORS and Euro-ORS contained only glucose. In normal small intestine, water absorption was greater from Glu-ORS than Suc/cit-ORS or Euro-ORS, although water absorption was similar from Suc/cit-ORS and Suc/Cl-ORS. In the rotavirus model, Glu-ORS produced more water absorption than Euro-ORS or either sucrose ORS. In both models, Suc/cit-ORS caused sodium and chloride secretion. Glucose absorption was similar from all ORSs. These findings indicate that attempts to improve ORS palatability by adding sucrose or increasing citrate at the expense of chloride would incur a significant penalty in terms of salt and water absorption.

Alanine- and glucose-based hypo-osmolar oral rehydration solution in infants with persistent diarrhoea: a controlled trial

To evaluate the efficacy of a hypo-osmolar and a standard (World Health Organization) oral rehydration salt (ORS) solution in persistent diarrhoea, a randomized controlled clinical trial was conducted in 55 children. After a 1-day observation period the children were assigned to one of three solutions: standard ORS (WHO-ORS) (osmolality 311 mosmol/l), hypo-osmolar ORS containing L-alanine and glucose (osmolality 255 mosmol/l) and i.v. polyelectrolyte solutions (osmolality 293 mosmol/l) for ongoing replacement of stool loss for the next 4 days. Excellent acceptability of ORS (101-160 ml/kg body weight/day) by the children was observed. There were no significant differences in the total intake of solutions and food, and frequency of stools among the groups. Stool outputs were significantly less in infants receiving hypo-osmolar ORS than in those receiving WHO-ORS for 0-24 h (p = 0.04), 0-48 h (p = 0.01), 0-72 h (p = 0.04) and 0-96 h (p = 0.03). The results indicate a sufficient scope of ORS practice in persistent diarrhoea. Furthermore, we found that a hypo-osmolar ORS containing L-alanine and glucose is as efficacious as an iv solution and more effective than WHO-ORS for replacement of ongoing stool loss in persistent diarrhoea.

Why treatment centres failed to prevent cholera deaths among Rwandan refugees in Goma, Zaire

In July, 1994, in one of the worst cholera outbreaks in recent times, an estimated 12,000 Rwandan refugees died in Goma in eastern Zaire. The Vibrio cholerae strains were resistant to tetracycline and doxycycline, the commonly used drugs for cholera treatment. Despite the efforts of international organisations, which provided medical relief by establishing treatment centres in Goma, mortality from the disease was much higher than expected. In the area of Muganga camp, which had the largest concentration of refugees and where most of the medical aid organisations were active, the highest reported case-fatality ratio for a single day was 48%. The slow rate of rehydration, inadequate use of oral rehydration therapy, use of inappropriate intravenous fluids, and inadequate experience of health workers in management of severe cholera are thought to be some of the factors associated with the failure to prevent so many deaths during the epidemic. In one of the temporary treatment centres with the worst case-fatality record, our team showed that improvement of these factors could increase the odds of survival of cholera patients even in a disaster setting.

Rehydration and nutritional management

Diarrhoea remains a leading worldwide cause of morbidity and mortality. In developing countries alone, 1.5 billion episodes of diarrhoea occur per year in children under 5 years of age and approximately 4,000,000 of these result in death. Early, appropriate therapy decreases the risk of complications and death due to diarrhoea. Regardless of the causative agent, oral rehydration and nutritional management are the mainstays of good management of infants, children and adults with diarrhoea. Diarrhoeal disease control programmes throughout the developing world have adopted the WHO case management plan as a standard. In this chapter, we review the history, successes and shortcomings of various oral rehydration therapies and recommend a case management approach that is similar to the WHO plan. Although ORT is safe, effective, convenient and economical, this therapy has not been universally implemented in health care settings. The challenge for clinical and public health practitioners in developing and developed countries is to identify and overcome the barriers that exist so that all patients with diarrhoea will have the opportunity to receive optimal care.

Clinical and bacteriological studies of El Tor cholera after ingestion of known inocula in Thai volunteers

Twenty-six healthy adult Thai volunteers were recruited for clinical and bacteriological studies of cholera induced by oral inoculation with Vibrio cholerae El Tor Inaba strain N16961. Vibrio dosages of 0.3 x 10(4), 1.6 x 10(5) and 1.9 x 10(6) c.f.u. were given to three groups of five volunteers, and 2.0 x 10(7) c.f.u. to 11 volunteers. Diarrhoeal attack rates correlated positively with the size of the inocula (p less than 0.01). It was estimated that a diarrhoeal attack rate of 90% (ED90) would be achievable by inoculation of 1.3 x 10(7) c.f.u. of the organisms. There were no significant differences between the groups in the latent period to positive stool culture, maximum vibrio count per gram of stool and duration of stool positivity. The ED90 of V. cholerae obtained may be used as a challenge dose in subsequent studies on protective efficacy of cholera vaccines in Thai adult volunteers.

Blood and urine responses to ingesting fluids of various salt and glucose concentrations

Several hours before returning to Earth, Space Shuttle astronauts consume fluid and salt tablets equivalent to a liter of 0.9% saline as a countermeasure to postflight orthostatic intolerance. This countermeasure is not completely successful. Therefore, in search of a countermeasure that would protect against orthostatic intolerance better and for a longer duration, the authors compared the blood and urine responses of five men (21-41 yr) after they drank 1 L of 0.9% saline to their responses after drinking five other solutions: distilled water, 1% glucose, 0.74% saline with 1% glucose, 0.9% saline with 1% glucose, and 1.07% saline. Each subject ingested a different solution on 6 different days and remained seated for the ensuing 4 hours. Heart rate, blood pressures, and urine variables were measured before ingestion of the fluids and every 30 minutes thereafter; blood samples were drawn before, immediately after, and every 60 minutes after ingestion. Change in plasma volume, which was estimated from hemoglobin and hematocrit, was considered the most critical variable. Data for all solutions were compared by analysis of variance. Since plasma volume was increased most after ingestion of 1.07% saline, all variables (at 2 hours, at 3 hours and at 4 hours) were compared between 1.07% saline and 0.9% saline, the current countermeasure. Plasma volume was increased more after 1.07% saline than after 0.9% saline, and this difference was most significant at 4 hours after ingestion (P = .056). Diuresis occurred promptly after ingestion of the two saline-free solutions, water and 1% glucose.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine-based oral rehydration therapy for infants with acute diarrhea

Twenty male infants less than 1 year of age with acute diarrhea and dehydration were randomly assigned to a study group and studied in blind fashion in a metabolic unit to assess the efficacy of the addition of 30 mmol/L alanine to the standard World Health Organization (WHO) oral rehydration solution (ORS). Patients were exclusively rehydrated with one of two types of ORS during the first 24 hours of treatment. On the second day, oral feedings were started with a lactose-free formula, and ORS was given to replace stool losses. Body weight, ORS, food intake, vomitus, stool, and urine output were recorded at 6-hour intervals. Blood was drawn at the time of admission, after rehydration, and at 24 and 48 hours of hospitalization to monitor blood gases and electrolytes. Rehydration was satisfactory in both groups of patients. ORS that contained alanine did not reduce the purging rates of the infants compared with those who received standard ORS. Clinically no adverse effect of the alanine-based ORS was observed during hospitalization. None of the patients had significant hypernatremia or hyponatremia, and serum amino acid levels were not altered. These data show that the addition of 30 mmol/L alanine to the standard WHO-ORS produces no further improvement in the outcome of the infants with acute diarrhea compared with those fed the standard WHO-ORS.

Optimising oral rehydration solution composition for the children of Europe: clinical trials

Clinical trials testing different oral rehydration solutions (ORS) are reviewed. The effects of individual components and their concentrations are analysed in order to establish margins of safety for the composition of the ideal ORS for children in Europe. Glucose is the solute of choice for ORS and concentrations of 70-140 mmol/l are adequate. Glucose may be replaced by sucrose or glucose polymers. "Low" sodium concentrations (35-60 mmol/l) are advised for rehydration and maintenance in acute non-cholera diarrhoea, for children of all ages, including neonates, and for any degree of dehydration except shock. Although intended for children who are not malnourished, the European ORS should have an adequate potassium concentration (20-30 mmol/l), namely the same concentration as found in WHO-ORS. Chloride concentration depends upon other constituents of ORS, namely sodium and potassium, but the range of 30-90 mmol/l is considered to be adequate. Base or base precursors are not required for correction of acidosis except in the severe cases that always need intravenous replacement. A relatively low osmolality seems advisable.

Oral rehydration formula containing alanine and glucose for treatment of diarrhoea: a controlled trial

OBJECTIVE

To determine whether adding L-alanine to the glucose based oral rehydration solution recommended by the World Health Organisation would improve its efficacy in treating acute diarrhoea.

DESIGN

Randomised double blind controlled trial of oral rehydration solution containing L-alanine and glucose.

SETTING

Inpatient service of a hospital treating diarrhoea.

PATIENTS

97 Male patients aged 6-59 years admitted to the hospital with acute and severe dehydration due to diarrhoea associated with Vibrio cholerae or enterotoxigenic Escherichia coli. Forty nine received the standard glucose based oral rehydration solution (control group) and 48 this solution with alanine added (study group).

INTERVENTIONS

All of the patients received rapid intravenous acetate solution for the initial four hours after admission, which fully corrected the signs of dehydration. They were then admitted to the study and randomised. Immediately after the intravenous treatment oral rehydration treatment was started. All of the patients received oral tetracycline for 48 hours, starting 24 hours after start of the study. If signs of dehydration reappeared during oral treatment patients were given rapid intravenous acetate solution until they were fully corrected and then continued to take the assigned oral rehydration solution.

END POINT

Passage of the last watery stool.

MEASUREMENTS AND MAIN RESULTS

The median stool output/kg body weight during the initial 24 hours of oral rehydration treatment and until diarrhoea stopped was reduced in the study group compared with the control group from 309 ml to 196 ml and from 393 ml to 236 ml respectively. Intake of oral rehydration solution and intravenous acetate solution was reduced from 455 ml to 308 ml and from 616 ml to 425 ml respectively. Two patients in the study group compared with 18 patients in the control group required unscheduled rapid intravenous acetate solution to correct signs of dehydration during oral rehydration treatment.

CONCLUSION

Oral rehydration solution containing L-alanine was considerably better than standard oral rehydration solution at reducing the severity of symptoms and the need for fluid of male patients with diarrhoea associated with V cholerae and enterotoxigenic E coli.

Studies on mechanisms of diarrhea induced by fusarenon-X, a trichothecene mycotoxin from Fusarium species: fusarenon-X-induced diarrhea is not mediated by cyclic nucleotides

Cardinal signs of red mold toxicosis in man and farm animals are vomiting, nausea, diarrhea, and food refusal. The red mold toxicosis has been suggested to be induced by trichothecenes, which are produced by Fusarium fungi. Fusarenon-X (F-X) is one of the trichothecene mycotoxins. The ip injection of F-X to rats causes an expansion of the small intestine and watery diarrhea. In this study, we measured the concentrations of protein, sodium, potassium, and calcium in the serum of rat treated with F-X for the sake of demonstrating the loss of serum protein and the decreases of serum sodium and calcium by F-X. Since it is well known that some diarrheal diseases are due to the increase of cyclic nucleotide level in the intestinal mucosa, we also measured cyclic AMP and cyclic GMP levels in the intestinal mucosa. It was demonstrated that F-X did not increase the cyclic AMP and cyclic GMP levels in the jejunal and the ileal mucosa at 8 and 24 hr after F-X treatment. The results obtained in this work suggest that F-X-induced diarrhea is not mediated by the cyclic nucleotide system.

The acidosis of cholera. Contributions of hyperproteinemia, lactic acidemia, and hyperphosphatemia to an increased serum anion gap

To study the metabolic acidosis that occurs during the diarrhea of cholera, we examined the serum anion gap in 21 patients with hypovolemic shock due to Vibrio cholerae infection. Measurements of serum electrolytes, as well as divalent cations and the anionic contributions of serum proteins, lactate, phosphate, and serum creatinine, were made at the time of admission, after rehydration, and during convalescence. At the time of admission, the mean serum concentration of sodium was 134.8 mmol (meq) per liter, that of chloride was 103.2 mmol per liter, and that of bicarbonate was 11.4 mmol per liter; the mean anion gap was 20.2 mmol per liter. The mean serum creatinine concentration was 2.48 mg per deciliter. The low serum bicarbonate level and the high serum anion gap were corrected by rehydration. The increased serum anion gap was caused by hyperproteinemia, lactic acidemia, and hyperphosphatemia, with anionic contributions to the rise in anion gap estimated as protein, 5.5 meq per liter; lactate, 2.5 meq per liter; and phosphate, 2.5 meq per liter. The hyperproteinemia was attributed to dehydration, the lactic acidemia to shock, and the hyperphosphatemia to acidosis and transient renal failure. The mean concentrations of serum calcium and magnesium were slightly elevated but did not affect the increased anion gap. These results indicate that severe cholera causes acidosis with relatively little change in serum chloride but an increased serum anion gap. The acidosis is more profound than would be expected on the basis of stool losses of bicarbonate, because of superimposed lactic acidemia and renal failure.

Prevention and treatment of infectious diarrhea. Speculations on the next 10 years

The next decade should explode with exciting schemes and novel agents for the prevention and treatment of infectious diarrhea. The development of oral, nonabsorbed antibiotics will continue, but new antidiarrheal drugs, such as gastrointestinal hormone analogues and alpha-adrenergic agonists, will be added to our therapeutic armamentarium. Improved oral rehydration solutions, such as glycine in electrolyte solution, promise to revolutionize the management of diarrhea by diminishing diarrheal stool volume to the point where losses are too small to be clinically relevant. Infant formulas and adult oral solutions fortified with antibodies raised against selected enteropathogens may provide a way to prevent infectious diarrheas in infants and travelers. Advances in genetic engineering will usher in a new era of experimental and licensed enteric vaccines, including those against cholera, Escherichia coli, Shigella, typhoid fever, and rotavirus.

Effect of Different Drinks on Fluid and Electrolyte Losses from a Jejunostomy

The effectiveness of 5 different solutions on the absorption of fluid and electrolytes was tested in 7 patients with a proximal intestinal stoma and large fluid losses, all of whom previously needed intravenous infusions to maintain balance. In 4 patients it proved possible to replace the intravenous infusions with an enteral supplement. The WHO glucose/electrolyte solution without added potassium (NaCl 3.5 g, NaHCO3 2.5 g, glucose 20 g/l) gave satisfactory results, though was slightly less effective than a solution containing more sodium in which maltose was substituted for glucose. Neither sucrose nor an oligosaccharide*** (Caloreen) gave an advantage over glucose in the formulations used. In 3 patients losses were so great, and absorption of sodium from oral solutions so small, that intravenous supplements had to be continued. These 3 patients could be distinguished from the other 4 by the fact that more than 250 ml emerged from the stoma during the 3 hours after a drink of 500 ml of glucose/electrolyte solution. In all patients a drink of water or tea led to a loss of sodium from the stoma; water should be restricted in such patients and replaced by a glucose/electrolyte solution.

5-hydroxytryptamine and cholera secretion. Physiological and pharmacological studies in cats and rats

The intestinal secretion evoked by close intra-arterial infusion of 5-hydroxytryptamine (5-HT) in cats was inhibited by tetrodotoxin, a drug abolishing action potentials. Furthermore, the intestinal secretion produced by placing a 2-mM 5-HT solution in the intestinal lumen of rats was inhibited by hexamethonium, a ganglionic receptor-blocking agent. These observations strongly indicate that 5-HT-induced secretion is, at least in part, neurally mediated. It was also shown that 5-HT receptors are involved in the pathophysiology of choleraic secretion, since the secretion was inhibited by making the experimental animal tachyphylactic against 5-HT. No effects of 5-HT tachyphylaxis were noted on fluid transport in normal intestines. The results are discussed in relation to a new hypothesis for the pathophysiology of cholera secretion.

Rice-powder electrolyte solution as oral-therapy in diarrhoea due to Vibrio cholerae and Escherichia coli

124 patients with acute diarrhoea due to Vibrio cholerae or Escherichia coli were treated with either the standard sucrose-electrolyte solution or a cereal-based electrolyte solution, containing 30 g rice powder per litre and electrolytes as recommended by the World Health Organisation. The treatments were compared by measuring the rate of purging, change in body weight, serum specific gravity, urine output, and post-hydrolysis sugar content in the stool. The proportions of successfully treated patients in the rice-powder group were 80% for cholera patients and 88% for E. coli patients--no different from those in patients receiving the sucrose-electrolyte solution. Failure was due to rates of purging that exceeded the patient's ability to drink enough replacement solution. This study suggests that a rice-powder electrolyte solution is efficient and safe to use as a rehydrating oral fluid in acute diarrhoea.

Controlled trial of chlorpromazine as antisecretory agent in patients with cholera hydrated intravenously

A randomised controlled trial was conducted to investigate the ability of chlorpromazine to reduce intestinal secretion in cholera. Chlorpromazine had reduced loss of intestinal fluid in animals with diarrhoea induced by cholera toxin, and in a preliminary study the drug had reduced purging in patients with cholera. Forty-six adults with cholera were included in the randomised trial. Of these, 34 were treated with chlorpromazine (1 mg/kg or 4 mg/kg either by mouth or intramuscularly) and 12 served as controls. After treatment with the drug there was a significantly greater reduction in the rate of fluid loss in the treated patients than in the controls during the first (p less than 0.005), second (p less than 0.05), and fourth (p less than 0.01) eight-hour periods, but not during the third eight-hour period; the dose of 4 mg/kg was only marginally more effective than 1 mg/kg. The effect of chlorpromazine was strikingly biphasic, with one peak during the first eight hours and another 24-32 hours after administration. Chlorpromazine also significantly reduced the duration of diarrhoea, frequency of vomiting, and amount of intravenous fluid required. The drug induced mild sedation and no hypotension in these well-hydrated patients. These findings confirm the effectiveness of chlorpromazine in reducing fluid loss in cholera. A sedative effect, however, especially in children, may limit its usefulness and requires further study.

Actions of cholera toxin and the prevention and treatment of cholera

The drastic intestinal secretion of fluid and electrolytes that is characteristic of cholera is the result of reasonably well understood cellular and biochemical actions of the toxin secreted by Vibrio cholerae. Based on this understanding it is possible to devise new techniques for the treatment and prophylaxis of cholera to complement those based on fluid replacement therapy and sanitation.

The solid state stability of oral rehydration salts

The stability of rehydration salts (Electrolyte Powder B.P.C.) used in the treatment of infantile diarrhoea and cholera, was investigated by examining the discolouration of the salts under different conditions. Colourimetric measurements were obtained with a reflectometer. Browning reactions in the electrolyte solutions were followed by absorption at 284 nm and by the thiobarbituric acid reaction at 443 nm. The original white colour of the mixture began to turn yellow during the second week of exposure at 50 +/- 1 degree C under human conditions. Storage at room temperature caused discolouration only after four weeks. Of the three Hunter's values L, a, b the degree of b increased significantly. Discolouration of the mixture was accompanied by spectral changes. The peaks of the spectra shifted uniformly but did not reach 284 nm. The plot of Hunter's L, a, b against time indicated that decomposition of glucose in the powder into early intermediates followed apparent zero order kinetics. Polymerisation of these intermediates after prolonged storage under adverse conditions is a possibility. It is therefore justifiable to conclude that the rehydration salts should be prepared extemporaneously when required unless strict storage conditions are adhered to.