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The American Journal of Tropical... Nov 2017Globally, approximately 2 billion people lack microbiologically safe drinking water. Boiling is the most prevalent household water treatment method, yet evidence of its... (Meta-Analysis)
Meta-Analysis Review
Globally, approximately 2 billion people lack microbiologically safe drinking water. Boiling is the most prevalent household water treatment method, yet evidence of its health impact is limited. To conduct this systematic review, we searched four online databases with no limitations on language or publication date. Studies were eligible if health outcomes were measured for participants who reported consuming boiled and untreated water. We used reported and calculated odds ratios (ORs) and random-effects meta-analysis to estimate pathogen-specific and pooled effects by organism group and nonspecific diarrhea. Heterogeneity and publication bias were assessed using , meta-regression, and funnel plots; study quality was also assessed. Of the 1,998 records identified, 27 met inclusion criteria and reported extractable data. We found evidence of a significant protective effect of boiling for infections (OR = 0.31, 95% confidence interval [CI] = 0.13-0.79, = 4 studies), (OR = 0.35, 95% CI = 0.17-0.69, = 3), protozoal infections overall (pooled OR = 0.61, 95% CI = 0.43-0.86, = 11), viral infections overall (pooled OR = 0.83, 95% CI = 0.7-0.98, = 4), and nonspecific diarrheal outcomes (OR = 0.58, 95% CI = 0.45-0.77, = 7). We found no evidence of a protective effect for helminthic infections. Although our study was limited by the use of self-reported boiling and non-experimental designs, the evidence suggests that boiling provides measureable health benefits for pathogens whose transmission routes are primarily water based. Consequently, we believe a randomized controlled trial of boiling adherence and health outcomes is needed.
Topics: Developing Countries; Diarrhea; Drinking Water; Food Contamination; Food Microbiology; Humans; Water Microbiology; Water Purification; Waterborne Diseases
PubMed: 29016318
DOI: 10.4269/ajtmh.17-0190 -
PloS One 2015Cholera remains a significant threat to global public health with an estimated 100,000 deaths per year. Water, sanitation and hygiene (WASH) interventions are frequently... (Review)
Review
BACKGROUND AND METHODS
Cholera remains a significant threat to global public health with an estimated 100,000 deaths per year. Water, sanitation and hygiene (WASH) interventions are frequently employed to control outbreaks though evidence regarding their effectiveness is often missing. This paper presents a systematic literature review investigating the function, use and impact of WASH interventions implemented to control cholera.
RESULTS
The review yielded eighteen studies and of the five studies reporting on health impact, four reported outcomes associated with water treatment at the point of use, and one with the provision of improved water and sanitation infrastructure. Furthermore, whilst the reporting of function and use of interventions has become more common in recent publications, the quality of studies remains low. The majority of papers (>60%) described water quality interventions, with those at the water source focussing on ineffective chlorination of wells, and the remaining being applied at the point of use. Interventions such as filtration, solar disinfection and distribution of chlorine products were implemented but their limitations regarding the need for adherence and correct use were not fully considered. Hand washing and hygiene interventions address several transmission routes but only 22% of the studies attempted to evaluate them and mainly focussed on improving knowledge and uptake of messages but not necessarily translating this into safer practices. The use and maintenance of safe water storage containers was only evaluated once, under-estimating the considerable potential for contamination between collection and use. This problem was confirmed in another study evaluating methods of container disinfection. One study investigated uptake of household disinfection kits which were accepted by the target population. A single study in an endemic setting compared a combination of interventions to improve water and sanitation infrastructure, and the resulting reductions in cholera incidence.
DISCUSSION AND RECOMMENDATIONS
This review highlights a focus on particular routes of transmission, and the limited number of interventions tested during outbreaks. There is a distinct gap in knowledge of which interventions are most appropriate for a given context and as such a clear need for more robust impact studies evaluating a wider array of WASH interventions, in order to ensure effective cholera control and the best use of limited resources.
Topics: Cholera; Disease Outbreaks; Humans; Hygiene; Sanitation; Water Purification
PubMed: 26284367
DOI: 10.1371/journal.pone.0135676 -
Paediatrics and International Child... Nov 2018Background Vibrio cholerae is a highly motile Gram-negative bacterium which is responsible for 3 million cases of diarrhoeal illness and up to 100,000 deaths per year,...
Background Vibrio cholerae is a highly motile Gram-negative bacterium which is responsible for 3 million cases of diarrhoeal illness and up to 100,000 deaths per year, with an increasing burden documented over the past decade. Current WHO guidelines for the treatment of paediatric cholera infection (tetracycline 12.5 mg/kg four times daily for 3 days) are based on data which are over a decade old. In an era of increasing antimicrobial resistance, updated review of the appropriate empirical therapy for cholera infection in children (taking account of susceptibility patterns, cost and the risk of adverse events) is necessary. Methods A systematic review of the current published literature on the treatment of cholera infection in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was undertaken. International clinical guidelines and studies pertaining to adverse effects associated with treatments available for cholera infection were also reviewed. Results The initial search produced 256 results, of which eight studies met the inclusion criteria. Quality assessment of the studies was performed as per the Grading of Recommendations Assessment, Development and Evaluation guidelines. Conclusions In view of the changing non-susceptibility rates worldwide, empirical therapy for cholera infection in paediatric patients should be changed to single-dose azithromycin (20 mg/kg), a safe and effective medication with ease of administration. Erythromycin (12.5 mg/kg four times daily for 3 days) exhibits similar bacteriological and clinical success and should be listed as a second-line therapy. Fluid resuscitation remains the cornerstone of management of paediatric cholera infection, and prevention of infection by promoting access to clean water and sanitation is paramount.
Topics: Adolescent; Anti-Bacterial Agents; Azithromycin; Child; Child, Preschool; Cholera; Drug Resistance, Bacterial; Drug-Related Side Effects and Adverse Reactions; Erythromycin; Guidelines as Topic; Humans; Infant; Infant, Newborn; Treatment Outcome; Vibrio cholerae; World Health Organization
PubMed: 29790841
DOI: 10.1080/20469047.2017.1409452 -
PloS One 2011There is a pressing need for effective measures to prevent the spread of cholera. Our systematic review assesses the effects of chemoprophylaxis in preventing cholera... (Review)
Review
INTRODUCTION
There is a pressing need for effective measures to prevent the spread of cholera. Our systematic review assesses the effects of chemoprophylaxis in preventing cholera among exposed contacts.
METHODS AND FINDINGS
We considered published and unpublished reports of studies up to July 2011. For this we searched: PubMed (1966 to July, 2011), Embase (1980 to July 2011), Cochrane Central Register of Controlled Trials (6; 2011), LILACS (1982 to July, 2011), the International Clinical Trials Registry Platform (July 2011) and references of identified publications. We included controlled clinical trials (randomized and non-randomized) in which chemoprophylaxis was used to prevent cholera among patient contacts. The main outcome measures were hospitalization and laboratory diagnosis of cholera in contacts for cholera patients. We assessed the risk of bias. We identified 2638 references and these included 2 randomized trials and 5 controlled trials that added up to a total of 4,154 participants. The risk of bias scored high for most trials. The combined results from two trials found that chemoprophylaxis reduced hospitalization of contacts during the follow-up period by 8-12 days (2826 participants; RR 0.54 95% CI 0.40-0.74;I² 0%). A meta-analysis of five trials found a significant reduction in disease among contacts with at least one positive sample who received chemoprophylaxis during the overall follow-up (range 4-15 days) (1,414 participants; RR 0.35 95% CI 0.18-0.66;I² 74%). A significant reduction in the number of positive samples was also found with chemoprophylaxis (3 CCT; 6,918 samples; RR 0.39 95% CI 0.29-0.51;I² 0%).
CONCLUSION
Our findings suggest that chemoprophylaxis has a protective effect among household contacts of people with cholera but the results are based on studies with a high risk of bias. Hence, there is a need for adequate reliable research that allows balancing benefits and harms by evaluating the effects of chemoprophylaxis.
Topics: Chemoprevention; Cholera; Humans; Meta-Analysis as Topic
PubMed: 22102873
DOI: 10.1371/journal.pone.0027060 -
PLoS Neglected Tropical Diseases Jun 2017Infectious diseases attributable to unsafe water supply, sanitation and hygiene (e.g. Cholera, Leptospirosis, Giardiasis) remain an important cause of morbidity and... (Review)
Review
Infectious diseases attributable to unsafe water supply, sanitation and hygiene (e.g. Cholera, Leptospirosis, Giardiasis) remain an important cause of morbidity and mortality, especially in low-income countries. Climate and weather factors are known to affect the transmission and distribution of infectious diseases and statistical and mathematical modelling are continuously developing to investigate the impact of weather and climate on water-associated diseases. There have been little critical analyses of the methodological approaches. Our objective is to review and summarize statistical and modelling methods used to investigate the effects of weather and climate on infectious diseases associated with water, in order to identify limitations and knowledge gaps in developing of new methods. We conducted a systematic review of English-language papers published from 2000 to 2015. Search terms included concepts related to water-associated diseases, weather and climate, statistical, epidemiological and modelling methods. We found 102 full text papers that met our criteria and were included in the analysis. The most commonly used methods were grouped in two clusters: process-based models (PBM) and time series and spatial epidemiology (TS-SE). In general, PBM methods were employed when the bio-physical mechanism of the pathogen under study was relatively well known (e.g. Vibrio cholerae); TS-SE tended to be used when the specific environmental mechanisms were unclear (e.g. Campylobacter). Important data and methodological challenges emerged, with implications for surveillance and control of water-associated infections. The most common limitations comprised: non-inclusion of key factors (e.g. biological mechanism, demographic heterogeneity, human behavior), reporting bias, poor data quality, and collinearity in exposures. Furthermore, the methods often did not distinguish among the multiple sources of time-lags (e.g. patient physiology, reporting bias, healthcare access) between environmental drivers/exposures and disease detection. Key areas of future research include: disentangling the complex effects of weather/climate on each exposure-health outcome pathway (e.g. person-to-person vs environment-to-person), and linking weather data to individual cases longitudinally.
Topics: Climate; Communicable Diseases; Models, Biological; Water Microbiology; Weather
PubMed: 28604791
DOI: 10.1371/journal.pntd.0005659 -
BMC Public Health 2013Diarrhea is a leading cause of mortality in children under 5 years along with its long-term impact on growth and cognitive development. Despite advances in the... (Review)
Review
BACKGROUND
Diarrhea is a leading cause of mortality in children under 5 years along with its long-term impact on growth and cognitive development. Despite advances in the understanding of diarrheal disorders and management strategies, globally nearly 750,000 children die annually as a consequence of diarrhea.
METHODS
We conducted a systematic review of the efficacy and effectiveness studies. We used a standardized abstraction and grading format and performed meta-analyses for all outcomes. The estimated effect of cholera, shigella, Enterotoxigenic Escherichia coli (ETEC) and rotavirus vaccines was determined by applying the standard Child Health Epidemiology Reference Group (CHERG) rules.
RESULTS
A total of 24 papers were selected and analyzed for all the four vaccines. Based on the evidence, we propose a 74% mortality reduction in rotavirus specific mortality, 52% reduction in cholera incidence due to their respective vaccines. We did not find sufficient evidence and a suitable outcome to project mortality reductions for cholera, ETEC and shigella in children under 5 years.
CONCLUSION
Vaccines for rotavirus and cholera have the potential to reduce diarrhea morbidity and mortality burden. But there is no substantial evidence of efficacy for ETEC and shigella vaccines, although several promising vaccine concepts are moving from the development and testing pipeline towards efficacy and Phase 3 trials.
Topics: Bacterial Vaccines; Child; Child, Preschool; Cholera; Cholera Vaccines; Comorbidity; Diarrhea; Dysentery; Dysentery, Bacillary; Escherichia coli Infections; Humans; Immunization Schedule; Infant; Male; Rotavirus Infections; Shigella Vaccines; Viral Vaccines
PubMed: 24564510
DOI: 10.1186/1471-2458-13-S3-S11 -
PloS One 2019Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs) are associated with a high mortality rate that varies remarkably with host susceptibility.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs) are associated with a high mortality rate that varies remarkably with host susceptibility. Hepatic disease (HD) is considered the key risk factor for high VNSSTIs incidence and mortality; however, there is limited evidence in the literature to support this observation.
METHODOLOGY
We examined all reported cases of VNSSTIs and associated mortality rates between 1966 and mid-2018. The PubMed, Medline and Cochrane Library databases were systematically searched for observational studies on patients with VNSSTIs. Twelve studies with 1157 total patients with VNSSTIs were included in the analysis. From the pooled dataset, nearly half (46.8%) of the patients with VNSSTIs had HD. The mortality rate in HD patients with VNSSTIs was 53.9% (n = 292/542), which was considerably higher than the mortality rate of 16.1% (n = 99/615) in non-HD patients. Patients with HD contracted VNSSTIs were found to be two or more times (RR = 2.61, 95% CI = 2.14-3.19) as likely to die compared with those without HD. Besides, liver cirrhosis (LC), the end-stage HD, was confirmed to be a significant risk factor, with risk ratios of 1.84 (95% CI 1.21-2.79) and 2.00 (95% CI 1.41-2.85) when compared to non-LC and non-HD, respectively.
CONCLUSIONS
HD with or without LC can be associated with infections and complications from V. vulnificus. Clinicians should aggressively approach care and management of acutely and/or critically ill patients with VNSSTIs.
Topics: Humans; Incidence; Liver Diseases; Mortality; Odds Ratio; Skin Diseases, Bacterial; Soft Tissue Infections; Vibrio Infections; Vibrio vulnificus
PubMed: 31652263
DOI: 10.1371/journal.pone.0223513 -
PLoS Neglected Tropical Diseases Dec 2016Use of the oral cholera vaccine (OCV) is a vital short-term strategy to control cholera in endemic areas with poor water and sanitation infrastructure. Identifying,... (Review)
Review
BACKGROUND
Use of the oral cholera vaccine (OCV) is a vital short-term strategy to control cholera in endemic areas with poor water and sanitation infrastructure. Identifying, estimating, and categorizing the delivery costs of OCV campaigns are useful in analyzing cost-effectiveness, understanding vaccine affordability, and in planning and decision making by program managers and policy makers.
OBJECTIVES
To review and re-estimate oral cholera vaccination program costs and propose a new standardized categorization that can help in collation, analysis, and comparison of delivery costs across countries.
DATA SOURCES
Peer reviewed publications listed in PubMed database, Google Scholar and World Health Organization (WHO) websites and unpublished data from organizations involved in oral cholera vaccination.
STUDY ELIGIBILITY CRITERIA
The publications and reports containing oral cholera vaccination delivery costs, conducted in low- and middle-income countries based on World Bank Classification. Limits are humans and publication date before December 31st, 2014.
PARTICIPANTS
No participants are involved, only costs are collected.
INTERVENTION
Oral cholera vaccination and cost estimation.
STUDY APPRAISAL AND SYNTHESIS METHOD
A systematic review was conducted using pre-defined inclusion and exclusion criteria. Cost items were categorized into four main cost groups: vaccination program preparation, vaccine administration, adverse events following immunization and vaccine procurement; the first three groups constituting the vaccine delivery costs. The costs were re-estimated in 2014 US dollars (US$) and in international dollar (I$).
RESULTS
Ten studies were identified and included in the analysis. The vaccine delivery costs ranged from US$0.36 to US$ 6.32 (in US$2014) which was equivalent to I$ 0.99 to I$ 16.81 (in I$2014). The vaccine procurement costs ranged from US$ 0.29 to US$ 29.70 (in US$2014), which was equivalent to I$ 0.72 to I$ 78.96 (in I$2014). The delivery costs in routine immunization systems were lowest from US$ 0.36 (in US$2014) equivalent to I$ 0.99 (in I$2014).
LIMITATIONS
The reported cost categories are not standardized at collection point and may lead to misclassification. Costs for some OCV campaigns are not available and analysis does not include direct and indirect costs to vaccine recipients.
CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS
Vaccine delivery cost estimation is needed for budgeting and economic analysis of vaccination programs. The cost categorization methodology presented in this study is helpful in collecting OCV delivery costs in a standardized manner, comparing delivery costs, planning vaccination campaigns and informing decision-making.
Topics: Administration, Oral; Cholera; Cholera Vaccines; Cost-Benefit Analysis; Humans; Immunization Programs; Poverty; Sanitation; Vaccination; World Health Organization
PubMed: 27930668
DOI: 10.1371/journal.pntd.0005124 -
The Cochrane Database of Systematic... Dec 2016Acute diarrhoea is one of the main causes of morbidity and mortality among children in low-income countries. Glucose-based oral rehydration solution (ORS) helps replace... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Acute diarrhoea is one of the main causes of morbidity and mortality among children in low-income countries. Glucose-based oral rehydration solution (ORS) helps replace fluid and prevent further dehydration from acute diarrhoea. Since 2004, the World Health Organization (WHO) has recommended the osmolarity of less than 270 mOsm/L (ORS ≤ 270) versus greater than 310 mOsm/L formulation (ORS ≥ 310). Polymer-based ORS (for example, prepared using rice or wheat) slowly releases glucose and may be superior to glucose-based ORS.
OBJECTIVES
To compare polymer-based oral rehydration solution (polymer-based ORS) with glucose-based oral rehydration solution (glucose-based ORS) for treating acute watery diarrhoea.
SEARCH METHODS
We searched the following sources up to 5 September 2016: the Cochrane Infectious Diseases Group (CIDG) Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 9), MEDLINE (1966 to 5 September 2016), EMBASE (1974 to 5 September 2016), LILACS (1982 to 5 September 2016), and mRCT (2007 to 5 September 2016). We also contacted researchers, organizations, and pharmaceutical companies, and searched reference lists.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) of people with acute watery diarrhoea (cholera and non-cholera associated) that compared polymer-based and glucose-based ORS (with identical electrolyte contents).
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed the search results and risk of bias, and extracted data. In multiple-treatment arms with two or more treatment groups, we combined outcomes as appropriate and compared collectively with the control group.
MAIN RESULTS
Thirty-five trials that included 4284 participants met the inclusion criteria: 28 trials exclusively included children, five included adults, and two included both adults and children. Polymer-based ORS versus glucose-based ORS (osmolarity ≤ 270) Eight trials (752 participants) evaluated this comparison, and seven trials used rice as a polymer source. Polymer-based ORS may decrease mean stool output in the first 24 hours by 24 mL/kg (mean difference (MD) -24.60 mL/kg, 95% CI -40.69 to -8.51; one trial, 99 participants, low quality evidence). The average duration of diarrhoea may be reduced by eight hours (MD -8.24 hours, 95% CI -13.17 to -3.30; I² statistic = 86%, five trials, 364 participants, low quality evidence) with polymer ORS but results are heterogeneous. Limited trials showed no observed difference in the risk of unscheduled use of intravenous fluid (RR 0.66, 95% CI 0.43 to 1.02; I² statistic = 30%; four trials, 376 participants, very low quality evidence), vomiting (very low quality evidence), and hyponatraemia (very low quality evidence). Polymer-based ORS versus glucose-based ORS (osmolarity ≥ 310) Twenty-seven trials (3532 participants) evaluated this comparison using a variety of polymers. On average, polymer ORS may reduce the total stool output in the first 24 hours by around 65 mL/kg (MD -65.47 mL/kg, 95% CI -83.92 to -47.03; 16 trials, 1483 participants, low quality evidence), and may reduce the duration of diarrhoea by around eight hours (MD -8.57 hours; SD -13.17 to -4.03; 16 trials, 1137 participants, low quality evidence) with substantial heterogeneity. The proportion of participants that required intravenous hydration was low in most trials with fewer in the polymer ORS group (RR 0.75, 95% CI 0.57 to 0.98; 19 trials, 1877 participant, low quality evidence) . Subgroup analysis by type of pathogen suggested an effect on unscheduled intravenous fluid in those infected with mixed pathogens (RR 0.63, 95% CI 0.41 to 0.96; 11 trials, 928 participants, low quality evidence), but not in participants positive for Vibrio cholerae (RR 0.94, 95% CI 0.66 to 1.34; 7 trials, 535 participants, low quality evidence). No difference was observed in the number of patients who developed vomiting (RR 0.91, 95% CI 0.72 to 1.14; 10 trials, 584 participants, very low quality evidence), hyponatraemia (RR 1.82, 95% CI 0.52 to 6.44; 4 trials, 385 participants, very low quality evidence), hypokalaemia (RR 1.29, 95% CI 0.74 to 2.25; 2 trials, 260 participants, low quality evidence), or persistent diarrhoea (RR 1.28, 95% CI 0.68 to 2.41; 2 trials, 885 participants, very low quality evidence).
AUTHORS' CONCLUSIONS
Polymer-based ORS shows advantages compared to glucose-based ORS (at ≥ 310 mOsm/L). Comparisons favoured polymer-based ORS over ORS ≤ 270 but analysis was underpowered.
Topics: Acute Disease; Adult; Child; Cholera; Dehydration; Diarrhea; Fluid Therapy; Humans; Infant; Oryza; Polymers; Randomized Controlled Trials as Topic; Rehydration Solutions
PubMed: 27959472
DOI: 10.1002/14651858.CD006519.pub3 -
Systematic Reviews Apr 2022Waterborne diarrhea diseases are among the leading causes of morbidity and mortality globally. These diseases can be mitigated by implementing various interventions. We...
BACKGROUND
Waterborne diarrhea diseases are among the leading causes of morbidity and mortality globally. These diseases can be mitigated by implementing various interventions. We reviewed the literature to identify available interventions to mitigate the risk of waterborne diarrheal diseases.
METHODS
We conducted a systematic database review of CINAHL (Cumulative Index to Nursing and Allied Health Literature), PubMed, Web of Science Core Collection, Cochrane library, Scopus, African Index Medicus (AIM), and LILACS (Latin American and Caribbean Health Sciences Literature). Our search was limited to articles published between 2009 and 2020. We conducted the review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement checklist. The identified studies were qualitatively synthesized.
RESULTS
Our initial search returned 28 773 articles of which 56 studies met the inclusion criteria. The included studies reported interventions, including vaccines for rotavirus disease (monovalent, pentavalent, and Lanzhou lamb vaccine); enhanced water filtration for preventing cryptosporidiosis, Vi polysaccharide for typhoid; cholera 2-dose vaccines, water supply, water treatment and safe storage, household disinfection, and hygiene promotion for controlling cholera outbreaks.
CONCLUSION
We retrieved few studies on interventions against waterborne diarrheal diseases in low-income countries. Interventions must be specific to each type of waterborne diarrheal disease to be effective. Stakeholders must ensure collaboration in providing and implementing multiple interventions for the best outcomes.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42020190411 .
Topics: Animals; Caribbean Region; Cholera; Diarrhea; Disease Outbreaks; Humans; Sheep; Vaccines
PubMed: 35436979
DOI: 10.1186/s13643-022-01947-y