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Cholera, caused by Vibrio cholerae , is a severe diarrheal disease that necessitates prompt diagnosis and effective treatment. This review comprehensively examines various diagnostic methods, from traditional microscopy and culture to advanced nucleic acid testing like polymerase spiral reaction and rapid diagnostic tests, highlighting their advantages and limitations. Additionally, we explore evolving treatment strategies, with a focus on the challenges posed by antibiotic resistance due to the activation of the SOS response pathway in V. cholerae. We discuss promising alternative treatments, including low-pressure plasma sterilization, bacteriophages, and selenium nanoparticles. The paper emphasizes the importance of multidisciplinary approaches combining novel diagnostics and treatments in managing and preventing cholera, a persistent global health challenge. The current re-emergent 7th pandemic of cholera commenced in 1961 and shows no signs of abeyance. This is probably due to the changing genetic profile of V. cholerae concerning bacterial pathogenic toxins. Given this factor, we argue that the disease is effectively re-emergent, particularly in Eastern Mediterranean countries such as Lebanon, Syria, etc. This review considers the history of the current pandemic, the genetics of the causal agent, and current treatment regimes. In conclusion, cholera remains a significant global health challenge that requires prompt diagnosis and effective treatment. Understanding the history, genetics, and current treatments is crucial in effectively addressing this persistent and re-emergent disease. [ABSTRACT FROM AUTHOR]

In Bangladesh and West Bengal cholera is seasonal, transmission occurs consistently annually. By contrast, in most African countries, cholera has inconsistent seasonal patterns and long periods without obvious transmission. Transmission patterns in Africa occur during intermittent outbreaks followed by elimination of that genetic lineage. Later another outbreak may occur because of reintroduction of new or evolved lineages from adjacent areas, often by human travelers. These then subsequently undergo subsequent elimination. The frequent elimination and reintroduction has several implications when planning for cholera's elimination including: a) reconsidering concepts of definition of elimination, b) stress on rapid detection and response to outbreaks, c) more effective use of oral cholera vaccine and WASH, d) need to readjust estimates of disease burden for Africa, e) re-examination of water as a reservoir for maintaining endemicity in Africa. This paper reviews major features of cholera's epidemiology in African countries which appear different from the Ganges Delta. [ABSTRACT FROM AUTHOR]

Nigeria accounts for a substantial cholera burden globally, particularly in its northeast region, where insurgency is persistent and widespread. We used participatory group model building workshops to explore enablers and barriers to implementing known cholera interventions, including water, sanitation and hygiene, surveillance and laboratory, case management, community engagement, oral cholera vaccine, and leadership and coordination, as well as exploring leverage points for interventions and collaboration. The study engaged key cholera stakeholders in the northeastern States of Adamawa and Bauchi, as well as national stakeholders in Abuja. Adamawa and Bauchi States' group modes building participants comprised 49 community members and 43 healthcare providers, while the 23 national participants comprised government ministry, department and agency staff, and development partners. Data were analysed thematically and validated via consultation with selected participants. The study identified four overarching themes regarding the enablers and barriers to implementing cholera interventions: (1) political will, (2) health system resources and structures, (3) community trust and culture, and (4) spill-over effect of COVID-19. Specifically, inadequate political will exerts its effect directly (e.g. limited funding for prepositioning essential cholera supplies) or indirectly (e.g. overlapping policies) on implementing cholera interventions. The healthcare system structure (e.g. centralization of cholera management in a State capital) and limited surveillance tools weaken the capacity to implement cholera interventions. Community trust emerges as integral to strengthening the healthcare system's resilience in mitigating the impacts of cholera outbreaks. Lastly, the spill-over effects of COVID-19 helped promote interventions similar to cholera (e.g. water, sanitation and hygiene) and directly enhanced political will. In conclusion, the study offers insights into the complex barriers and enablers to implementing cholera interventions in Nigeria's cholera-endemic settings. Strong political commitment, strengthening the healthcare system, building community trust and an effective public health system can enhance the implementation of cholera interventions in Nigeria. [ABSTRACT FROM AUTHOR]

A list of books received for review is presented, including "Twenty-First Century Plague: The Story of SARS," by Thomas Abraham, "Fever of War: The Influenza Epidemic in the U.S. Army During World War I," by Carol R. Byerly, and "Health Security for All: Dreams of Universal Health Care in America," by Alan Derickson.

This paper attempts to evaluate competing theories forwarded by modern historians to explain the mortality caused by one of the most well-known famines in nineteenth-century India: the Madras famine of 1876–8. Some have suggested that the resumption of the monsoon rains after a period of prolonged drought created conditions favourable for the breeding and proliferation of malaria, deaths from which peaked after the worst period of starvation. Others have argued that the wave of mortality during the famine years can be traced to the dissemination of infectious diseases like cholera and dysentery by mobile, socially displaced populations. The paper finds that all of these explanations neglect a category of diseases which accounts for a third of all famine deaths. A re-assessment of the mortality statistics and the medical observations leads to the conclusion that starvation, rather than climate or social displacement, accounts for the bulk of deaths. [ABSTRACT FROM PUBLISHER]

Our understanding of the burden and drivers of cholera mortality is hampered by limited surveillance and confirmation capacity. Leveraging enhanced clinical and laboratory surveillance in the cholera-endemic community of Uvira, eastern Democratic Republic of Congo, we describe cholera deaths across 3 epidemics between September 2021 and September 2023 following mass vaccination. [ABSTRACT FROM AUTHOR]

The provision of health care service in resource-poor settings is associated with a broad set of ethical issues. Devakumar's case discusses the ethical issues related to the inability to treat in a cholera clinic patients who do not have cholera. This paper gives a closer look on the context in which Devakumar's case took place. It also analyses the potential local and organizational factors that gives rise to ethical dilemmas and aggravate them. It also proposes a framework to help in the proactive handling of the factors that leads to ethical dilemmas and resolving the ethical issues as they appear. It adopts the four principles of autonomy, beneficence, non-maleficence and justice as universal and prima facie principles, but with the inclusion of a local understanding of what of each of these principles means. It is based on a collaborative approach that involves the beneficiaries and other partners in the field to help share information and resources, as well as adopting the provision of a wider service to the whole community. This is done by asking three basic questions: (a) who are the relevant stakeholders? (b) what ought to be the ethical principles in place? and (c) how should we take, implement and follow the decision about service provision? [ABSTRACT FROM PUBLISHER]

Background: The seventh cholera pandemic has been ongoing in Mexico since 1991 and threatens to become endemic. This paper aims to determine the geographical pattern of cholera in Mexico to define areas at high risk of endemic cholera.Methods: Ecologic research was conducted based upon the cartography of disease incidence. The 32 Mexican states were grouped into five strata according to the value of the 1991-1996 cumulative incidence rate of cholera. Rate ratios were computed for strata of states classified by geographical situation, urbanization, and poverty level.Results: Cholera incidence was 2.47 times higher in coastal states than in the interior (95% CI : 2.42-2.52). The disease was negatively associated with urbanization. Incidence in the least urbanized stratum was four times as high as in the most urban stratum (95% CI : 3.9-4.12). The poorest stratum showed the most remarkable incidence, i.e. 5.9 times higher than the rate in the least poor stratum (95% CI : 5.73-6.04).Conclusions: This ecologic research suggests that high poverty level, low urbanization, and southern location are the most important predictors of endemic cholera in Mexican states. It is hypothesized that the natural environment of the coastal plains in southern states may also play a significant role in cholera incidence. Poor communities residing in the southern, predominantly rural, coastal states should be prioritized when it comes to investing in safe water supply facilities, adequate excreta disposal systems and cholera surveillance. [ABSTRACT FROM AUTHOR]

In a previous paper we showed that the B-pentamer of cholera toxin (CT-B) binds with reduced binding strength to different C(l) derivatives of N-acetylneuraminic acid (NeuAc) of the natural receptor ganglioside, GM1. We have now extended these results to encompass two large amide derivatives, butylamide and cyclohexylmethylamide, using an assay in which the glycosphingolipids are adsorbed on hydrophobic PVDF membranes. The latter derivative showed an affinity approximately equal to that earlier found for benzylamide (∼0.01 relative to native GM1) whereas the former revealed a approximately tenfold further reduction in affinity. Another derivative with a charged C(l)-amide group, amino-propylamide, was not bound by the toxin. Toxin binding to C(7) derivatives was reduced by about 50% compared with the native ganglioside. Molecular modeling of C(l) and C(7) derivatives in complex with CT-B gave a structural rationale for the observed differences in the relative affinities of the various derivatives. Loss of or altered hydrogen bond interactions involving the water molecules bridging the sialic acid to the protein was found to be the major cause for the observed drop in CT-B affinity in the smaller derivatives, while in the bulkier derivatives, hydrophobic interactions with the protein were found to partly compensate for these losses. [ABSTRACT FROM AUTHOR]

This study focuses on the history of the quarantine system established at the naval border of the Romanian Principalities (Wallachia and Moldavia) between 1830 and 1859. We survey both the state's ability to organise defences against contagious diseases and the society's reaction to strict quarantine rules. In the end, we show that the Danube quarantine was not only a means of combating contagious diseases but also an instrument of pressure, surveillance and state regulation. To reconstruct an image of that period, we used information from five categories of sources: archive documents, health legislation, the press of the time, memoirs and diplomatic reports. By bringing the Romanian quarantine experience to the foreground, this study broadens both the perspective on quarantines and modernisation in the Romanian Principalities and also the knowledge regarding the free movement, politics and economy at the Danube border of the Ottoman Empire. [ABSTRACT FROM AUTHOR]

The immunity (or vaccine) passport of the coronavirus pandemic, as a concept and object, is not unprecedented. This health and identity document features a history spanning over half-a-millennium and appearing across diverse geopolitical and sociocultural contexts. This article presents a documentary history of the immunity passport and its heterogeneous material instantiations, uses and effects across divergent historical settings. It illuminates how the immunity passport has helped shaped identities and public health, as well as impacted individual and institutional agency, during health crises. Four historical cases are explored, including the plagues ravaging the Renaissance Mediterranean region, the 1665 Great Plague of London, the yellow fever outbreaks in the antebellum slave-era southern USA and the chronic cholera conditions confronting colonial-era British India. Although disparate, these historical cases share the immunity passport as a non-pharmaceutical intervention into their respective health crises that played important roles in people's lives during these troubled times. [ABSTRACT FROM AUTHOR]

We report on the sensitivity and specificity of stool culture compared to polymerase chain reaction for detecting Vibrio cholerae in Haiti during the waning period of the initial outbreak in 2018–2019. We found that stool culture (with a sensitivity of 33.3% and specificity of 97.4%) may not be sufficiently robust in this context. [ABSTRACT FROM AUTHOR]

A cholera outbreak in Blue Nile and Sennar states, south-eastern and southern Sudan, took place during September–December 2019. An outbreak surveillance sample collection was made. Vibrio cholerae O1 Ogawa was isolated from clinical samples of all confirmed 200 and 132 cases in Blue Nile state and Sennar state, respectively. The case fatality rate was higher in Blue Nile state, 4% compared with only 2.3% in Sennar state. The Euvichol-Plus oral cholera vaccine was rapidly deployed for the first time in Sudan to the most at-risk populations in the two affected states, 1 471 188 and 1 546 542 individuals in Sennar and Blue Nile states, respectively. The rapid deployment of cholera vaccines as the major prevention and control strategy was successful and helped greatly with the containment of this epidemic. In-depth genomics studies are crucial for understanding the disease dynamics in Sudan by identifying locally circulating strains of the bacteria and further improving prevention and control strategy by characterising the susceptibility and resistance of these locally circulating strains to currently used antibiotics. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "A New Perspective on John Snow's Communicable Disease Theory," by Winkelstein W in the previous issue of the journal.

Emergence and rapid spread of multidrug‐resistant (MDR) bacteria including Vibrio cholerae are a global public health issue. Much attention has been paid to natural compounds, such as spices and herbs to find novel antimicrobial compounds as they are considered to be cheaper alternatives to develop as a drug. Here, we show that methanol extract of white pepper could inhibit the growth of V. cholerae O1 El Tor variant, responsible for the recent outbreaks/epidemics. Furthermore, we demonstrate for the first time that piperine, the major component of white pepper, showed a dose‐dependent bactericidal effect on V. cholerae growth irrespective of their biotypes and serogroups in the presence of 200 and 300 µg ml−1 of piperine, respectively. Piperine also inhibited the growth of MDR strains of Pseudomonas aeruginosa, Escherichia coli isolated from poultry and enterohemorrhagic/enteroaggregative E. coli O104 in the presence of 200 µg ml−1. Interestingly, we did not observe any significant inhibitory effect of piperine on E. coli strains isolated from healthy person even up to 200 µg ml−1. Our data suggest that piperine could be a novel antimicrobial agent in therapeutic and preventive applications against infections caused by pathogenic bacteria including MDR strains. [ABSTRACT FROM AUTHOR]

Isolation of Vibrio cholerae O1 is necessary for cholera outbreak confirmation. Rapid diagnostic testing of fecal specimens, based on lipopolysaccharide detection of V. cholerae O1 or O139, may assist in early outbreak detection and surveillance. Cary-Blair transport medium is recommended for specimen transport. Filter paper, although used in epidemics, needs evaluation against rectal swab specimens. Fecal specimens are subcultured onto selective and nonselective media, including 5% blood agar and TCBS agar, for detection of V. cholerae O1 or O139. Suspicious, oxidase-positive isolates are serotyped in monovalent antisera. Antimicrobial-susceptibility testing is performed to detect resistance. Molecular characterization supports phenotypic identification and outbreak investigations. The presence of genes encoding cholera toxin, lipopolysaccharide, and El Tor biotype traits can be confirmed. Standardized pulsed-field gel electrophoresis analysis facilitates strain comparison. Quality management ensures reliability of results through validation and verification of functional laboratory equipment; quality control of testing procedures, laboratory reagents, and consumables; and participation in proficiency-testing schemes. [ABSTRACT FROM PUBLISHER]

Background: In the densely populated slums of Kolkata, informal healthcare providers' (IHP) diarrhea-related knowledge and rationality of practices should be improved to reduce risk of adverse outcome, expenditure, and antimicrobial resistance.Methods: A multicomponent intervention was conducted among 140 representative IHPs in the slums of 8 wards in Kolkata to assess its impact on their diarrhea-related knowledge and practice. Six intervention modules in local languages were provided (1 per month) with baseline (N = 140) and postintervention (N = 124) evaluation.Results: Mean overall (61.1 to 69.3; P < .0001) and domain-specific knowledge scores for etiology/spread (5.4 to 8.1; P < .0001), management (6.4 to 7.2; P < .0001), and oral rehydration solution ([ORS] 5.7 to 6.5; P < .0001) increased significantly (at α = 0.05) after intervention and were well retained. Impact on knowledge regarding etiology/spread (adjusted odds ratio [aOR] = 5.6; P < .0001), cholera (aOR = 2.0; P = .0041), management (aOR = 3.1; P < .0001), ORS (aOR = 2.3; P = .0008), and overall (aOR = 4.3; P < .0001) were significant. Intervention worked better for IHPs who practiced for ≥10 years (aOR = 3.2; P < .0001), untrained IHPs (aOR = 4.8; P < .0001), and pharmacists (aOR = 8.3; P < .0001). Irrational practices like empirical antibiotic use for every cholera case (aOR = 0.3; P < .0001) and investigation for every diarrhea case (aOR = 0.4; P = .0003) were reduced. Rationality of testing (aOR = 4.2; P < .0001) and antibiotic use (aOR = 1.8; P = .0487) improved.Conclusions: Multicomponent educational intervention resulted in sustainable improvement in diarrhea-related knowledge and practices among IHPs in slums of Kolkata. Policy implications should be advocated along with implementation and scale-up. [ABSTRACT FROM AUTHOR]

Mathematical modeling can be used to project the impact of mass vaccination on cholera transmission. Here, we discuss 2 examples for which indirect protection from mass vaccination needs to be considered. In the first, we show that nonvaccinees can be protected by mass vaccination campaigns. This additional benefit of indirect protection improves the cost-effectiveness of mass vaccination. In the second, we model the use of mass vaccination to eliminate cholera. In this case, a high population level of immunity, including contributions from infection and vaccination, is required to reach the "herd immunity" threshold needed to stop transmission and achieve elimination. [ABSTRACT FROM AUTHOR]

Cholera remains a major contributor of diarrheal diseases and leads to substantial morbidity and mortality, particularly in low socioeconomic settings. Nonavailability of a national cholera control plan in India, compounded by underreporting of cholera cases and deficient accurate cholera hotspot estimates, has made cholera control a challenge. Obstacles in the programmatic introduction of oral cholera vaccine (OCV) lie within the infrastructure-stockpile, costing, distribution system, cold-chain mechanism, vaccine logistics, and lack of strengthened surveillance systems for adverse events following immunization. Sustained political commitment along with collaboration of people working in the media will also determine the policy outcome of OCV introduction in India. [ABSTRACT FROM AUTHOR]

Cholera outbreaks currently account for 1.3 to 4.0 million cases and cause between 21 000 and 143 000 deaths worldwide. Cholera is preventable by proper sanitization and immunization; however, in many developing nations such as India, cholera disease is endemic. The surveillance system in India does not adequately capture the actual number of cases. As a result, it is important to utilize limited public health resources correctly in India and other developing counties more effectively to reach vulnerable communities. In this study, we analyze how studies make sense of cholera transmission and spread in India from 1996 to 2015. Furthermore, we analyze how a more sensitive surveillance system can contribute to cholera eradication by giving rise to outbreak preparedness. [ABSTRACT FROM AUTHOR]

Background: A surveillance system that is sensitive to detecting high burden areas is critical for achieving widespread disease control. In 2014, Bangladesh established a nationwide, facility-based cholera surveillance system for Vibrio cholerae infection. We sought to measure the sensitivity of this surveillance system to detect cases to assess whether cholera elimination targets outlined by the Bangladesh national control plan can be adequately measured.Methods: We overlaid maps of nationally representative annual V cholerae seroincidence onto maps of the catchment areas of facilities where confirmatory laboratory testing for cholera was conducted, and we identified its spatial complement as surveillance greyspots, areas where cases likely occur but go undetected. We assessed surveillance system sensitivity and changes to sensitivity given alternate surveillance site selection strategies.Results: We estimated that 69% of Bangladeshis (111.7 million individuals) live in surveillance greyspots and that 23% (25.5 million) of these individuals live in areas with the highest V cholerae infection rates.Conclusions: The cholera surveillance system in Bangladesh has the ability to monitor progress towards cholera elimination goals among 31% of the country's population, which may be insufficient for accurately measuring progress. Increasing surveillance coverage, particularly in the highest risk areas, should be considered. [ABSTRACT FROM AUTHOR]

Vaccine herd protection is the extension of the defense conferred by immunization beyond the vaccinated to unvaccinated persons in a population, as well as the enhancement of the protection among the vaccinated, due to vaccination of the surrounding population. Vaccine herd protection has traditionally been inferred from observations of disease trends after inclusion of a vaccine in national immunization schedules. Rather than awaiting outcomes of widescale vaccine deployment, earlier-stage evaluation of vaccine herd protection during trials or mass vaccination projects could help inform policy decisions about potential vaccine introduction. We describe the components, influencing factors, and implications of vaccine herd protection and discuss various methods for assessing herd protection, using examples from cholera and typhoid vaccine studies. [ABSTRACT FROM AUTHOR]

Epidemic Vibrio cholerae contain a large essential virulence gene cluster called the Vibrio pathogenicity island (VPI). We recently reported that no in vitro difference in virulence was found in El Tor strain N16961 containing a mutation in the VPI-encoded mop gene but this mutant was hypervirulent and reactogenic in rabbit ileal loops. In this paper, we report in vitro studies showing that independent Mop mutants of strain 3083 are significantly attenuated (∼40-fold) in cholera toxin (CT) production and have significantly increased motility and biofilm forming ability but appear to be unaffected in TcpA, hemagglutinin protease and hemolysin compared to their parent. The 3083 Mop mutant showed a 100-fold decrease in its in vivo intestinal colonization ability in the infant mouse competition assays. While reverse transcription polymerase chain reaction and phenotypic studies of a mop plasmid in both mutant and wild-type backgrounds suggest Mop is expressed by the plasmid, the differences in CT and biofilm formation could not be restored in any of the mutants. The inability to complement the Mop mutants in trans may be due either to the selection of secondary mutations or to mop possibly being part of an operon. Our findings that Mop is associated with CT, motility, biofilm formation and intestinal colonization support a hypothesis in which Mop has a pleiotropic role in the pathogenesis and persistence of epidemic V. cholerae. [Copyright &y& Elsevier]

After belatedly apologizing for the cholera epidemic in Haiti, the 'New Approach to Cholera in Haiti' by the UN and the promise of material assistance to victims through a 'victim-centred approach' highlight how the victims turn and the socio-economic turn are increasingly pivotal in the field of transitional justice. In light of these growing calls, we suggest a matrix to clarify the debate made of two separate dimensions: the focus of reparations – collective versus individual – and the means of reparations – symbolic versus material. Based on fieldwork conducted in March 2017 in the communities most affected by the cholera outbreak, this article demonstrates how the tensions between reparations offered by the UN (with a preference for collective symbolic reparations) and the reparations demanded by the victims (individual material reparations) can help understand the current stalemate in Haiti, and hopefully inform the next steps in the process of remedy for the victims. [ABSTRACT FROM AUTHOR]

UN Peacekeepers stationed on the banks of Haiti's largest river, the Artibonite, unleashed a cholera epidemic upon the country ten years ago, but the almost one million people affected still have not seen justice. This, despite the mobilization of grassroots organizations, human rights professionals, students, journalists and independent experts in international human rights law. This article aims to articulate rights violations in the Haiti cholera case, discuss the lack of accountability, and analyse efforts by advocates to overcome obstacles to justice through a multi-faceted intervention involving the UN Special Procedures system. Human rights-based approaches to UN accountability coupled with analyses of the UN's organizational immunity foreground the continued lack of remedy for the victims of cholera, which is a violation of their human rights attributable to the UN. In conducting public advocacy and investigating the issue of UN responsibility for cholera in Haiti, UN Special Rapporteurs like Philip Alston also relied on a human-rights based approach that built some public pressure for accountability. While advocates continue to push for accountability after a 10-year epidemic, and accountability is possible, the as-yet unsatisfactory resolution to the Haiti cholera case points to a need for UN reform to create more local, democratic structures of governance that are responsive to human rights obligations, in the face of considerable political, economic and social forces in Haiti and internationally that weigh against accountability. [ABSTRACT FROM AUTHOR]

In the 1890s, the American United Presbyterian Mission selected the Egyptian delta city of Tanta as the site for their new mission. Like the Egyptian government, these missionaries saw Tanta as a place that drew the sick. Their interest in the city developed mostly from the city's reputation as a site of cholera during the 1848 outbreak. Many ill and afflicted pilgrims came to Tanta to not only receive blessings from the patron saint Ahmad al-Badawi but also to be treated by the various healers, physicians and pharmacists around the mosque and tomb. This article shows that Tanta was a site of collaboration amongst female physicians and healers and posits that Tanta's system of health thrived most notably when these Christian missionaries worked within the local system of healers and embraced the culture of well-being rather than imposing modern attitudes about medicine and treatment. [ABSTRACT FROM AUTHOR]

Cholera remains a significant public health problem worldwide. In settings of declining incidence, serosurveillance may be used to augment clinical surveillance. We utilized dried blood spot sampling and cholera-specific antibody testing to examine the serologic profiles of vaccinated and unvaccinated children in southern Vietnam, where cholera was recently eliminated. [ABSTRACT FROM AUTHOR]

Zimbabwe's catastrophic cholera outbreak of 2008/09 resulted in an unprecedented 100,000 cases and nearly 5,000 deaths. In the aftermath of the epidemic, questions of suffering and death and of rescue, relief, and rehabilitation have persisted in on-going processes of meaning-making through which people come to terms with the epidemic as a 'man-made' disaster. Based on extensive fieldwork, I examine the views of residents in Harare's high-density townships that were epicentres of the disease. I argue that cholera was experienced by township residents as many crises at the same time. It was not only a public health crisis but also a political–economic crisis, a social crisis as well as a crisis of expectations, history and social identity. As such, I argue that the cholera outbreak was intensely generative of political subjectivities that reveal important shifts in the fraught relations between state and society in Zimbabwe's urban politics. Finally, I argue that the government's perceived causal role in, and failure to respond to, the cholera outbreak occasioned intense public outrage among township residents, which speaks to a much deeper aspiration for substantive citizenship based on political rights, social recognition, and access to high-quality public services delivered by a robust, responsible state. [ABSTRACT FROM AUTHOR]

Background Past research has suggested that the most cost-effective approach to using oral cholera vaccines (OCVs) to control endemic cholera may be to target only children <15 y of age. However, the assumption that vaccination of children with OCVs protects unvaccinated adults has never been tested. Methods We reanalyzed the data of an OCV trial in Bangladesh in which children 2–15 y of age and women >15 y of age were allocated to OCV or placebo and assessed herd protection by relating the risk of cholera in each nonvaccinated adult (>15 y) to OCV coverage (OCVC) of residents residing in virtual clusters within 500 m of the residence of that unvaccinated adult. Results The risk of cholera in unvaccinated adults decreased by 14% with each 10% increase of OCVC of all targeted age groups (95% 7 to 21%, p=0.0004). Also, the risk of cholera in unvaccinated adults decreased by 13% with each 10% increase in OCVC of children 2–15 y of age (95% CI 6 to 20%, p=0.0007). A high correlation between levels of OCVC of children and adult females precluded an assessment of the herd protection of unvaccinated adults by vaccinating children <16 y of age, independent of concomitant vaccination of adult women. Conclusions Unvaccinated adults benefitted from herd protection conferred by OCVs in this trial. Vaccination of children may be sufficient to confer this protection, but this possibility needs to be evaluated in further studies. [ABSTRACT FROM AUTHOR]

Background Niger has experienced multiple cholera outbreaks since the occurrence of cholera in West Africa in 1970–1971. Understanding the origins of these geographic variations at different scales in the region and in health districts is an essential step in the rational and operational fight against this disease. Methods We conducted a retrospective review of all suspected cholera cases in Niger from 2003 to 2015. Data from 2010 to 2015 were reviewed to determine the number and percentage of stool specimens tested, with distribution by serotype. We also determined the time between sampling and sending to a laboratory. Results From 2003 through 2015 a total of 16 328 cases of cholera, including 578 deaths, were reported to the National Surveillance Database (overall case fatality rate 3.5%). The number of cases was greater among males (63.29%). Patients >15 y of age accounted for 69.80% of cases. All regions recorded cholera cases throughout the period 2003 to 2015, except in 2009, when no outbreak was reported. All epidemics recorded were due to the subtype serogroup O1 serotype Ogawa and all strains confirmed the presence of the ctxB, rstR, tcpA, zot, ace and ctxA genes encoding the toxin of this serotype. Conclusions The global burden of cholera remains high in Niger. To successfully prevent and control outbreaks, adapted guidelines and strategies should be reviewed to provide more focused information and assign clear roles and responsibilities. [ABSTRACT FROM AUTHOR]

Cholera remains a major risk in developing countries, particularly after natural or man-made disasters. Vibrio cholerae El Tor is the most important cause of these outbreaks, and is becoming increasingly resistant to antibiotics, so alternative therapies are urgently needed. In this study, a single bacteriophage, Phi_1, was used to control cholera prophylactically and therapeutically in an infant rabbit model. In both cases, phage-treated animals showed no clinical signs of disease, compared with 69% of untreated control animals. Bacterial counts in the intestines of phage-treated animals were reduced by up to 4 log10 colony-forming units/g. There was evidence of phage multiplication only in animals that received a V. cholerae challenge. No phage-resistant bacterial mutants were isolated from the animals, despite extensive searching. This is the first evidence that a single phage could be effective in the treatment of cholera, without detectable levels of resistance. Clinical trials in human patients should be considered. [ABSTRACT FROM AUTHOR]

Pandemic cholera is a major concern for public health because of its high mortality and morbidity. Mutation accumulation (MA) experiments were performed on a representative strain of the current cholera pandemic. Although the base-pair substitution mutation rates in Vibrio cholerae (1.24 × 10−10 per site per generation for wild-type lines and 3.29 × 10−8 for mismatch repair deficient lines) are lower than that previously reported in other bacteria using MA analysis, we discovered specific high rates (8.31 × 10−8 site/generation for wild-type lines and 1.82 × 10−6 for mismatch repair deficient lines) of base duplication or deletion driven by large-scale copy number variations (CNVs). These duplication–deletions are located in two pathogenic islands, IMEX and the large integron island. Each element of these islands has discrepant rate in rapid integration and excision, which provides clues to the pandemicity evolution of V. cholerae. These results also suggest that large-scale structural variants such as CNVs can accumulate rapidly during short-term evolution. Mismatch repair deficient lines exhibit a significantly increased mutation rate in the larger chromosome (Chr1) at specific regions, and this pattern is not observed in wild-type lines. We propose that the high frequency of GATC sites in Chr1 improves the efficiency of MMR, resulting in similar rates of mutation in the wild-type condition. In addition, different mutation rates and spectra were observed in the MA lines under distinct growth conditions, including minimal media, rich media and antibiotic treatments. [ABSTRACT FROM AUTHOR]

While historians have tended to focus on overland emigrant's fears of Indians, the cholera years on the Overland Trail called into question Euro-American's preconception that they would die at the hands of so-called savages. The presence of cholera undercut the idea that male Argonauts would assert their masculinity by facing off against aggressive Indians. At the same time, the difficulty of finding appropriate female caregivers forced male emigrants to nurse each other. Emigrants addressed these challenges by describing a flexible, expansive white masculinity. This expansive masculinity helped to solve concerns about the nature of migration to California and about antebellum mobility more generally. [ABSTRACT FROM AUTHOR]

Background: Information on the impact of hygiene interventions on severe outcomes is limited. As a pre-specified secondary outcome of a cluster-randomized controlled trial among >400 000 low-income residents in Dhaka, Bangladesh, we examined the impact of cholera vaccination plus a behaviour change intervention on diarrhoea-associated hospitalization.Methods: Ninety neighbourhood clusters were randomly allocated into three areas: cholera-vaccine-only; vaccine-plus-behaviour-change (promotion of hand-washing with soap plus drinking water chlorination); and control. Study follow-up continued for 2 years after intervention began. We calculated cluster-adjusted diarrhoea-associated hospitalization rates using data we collected from nearby hospitals, and 6-monthly census data of all trial households.Results: A total of 429 995 people contributed 500 700 person-years of data (average follow-up 1.13 years). Vaccine coverage was 58% at the start of analysis but continued to drop due to population migration. In the vaccine-plus-behaviour-change area, water plus soap was present at 45% of hand-washing stations; 4% of households had detectable chlorine in stored drinking water. Hospitalization rates were similar across the study areas [events/1000 person-years, 95% confidence interval (CI), cholera-vaccine-only: 9.4 (95% CI: 8.3-10.6); vaccine-plus-behaviour-change: 9.6 (95% CI: 8.3-11.1); control: 9.7 (95% CI: 8.3-11.6)]. Cholera cases accounted for 7% of total number of diarrhoea-associated hospitalizations.Conclusions: Neither cholera vaccination alone nor cholera vaccination combined with behaviour-change intervention efforts measurably reduced diarrhoea-associated hospitalization in this highly mobile population, during a time when cholera accounted for a small fraction of diarrhoea episodes. Affordable community-level interventions that prevent infection from multiple pathogens by reliably separating faeces from the environment, food and water, with minimal behavioural demands on impoverished communities, remain an important area for research. [ABSTRACT FROM AUTHOR]

Background: : Cholera remains a serious public health threat in Asia, Africa and in parts of the Americas. Three World health Organization (WHO) pre-qualified oral cholera vaccines are now available but their supply is limited, so current supplies must be administered strategically. This requires an improved understanding of disease transmission and control strategies.Methods: : We used demographics and disease surveillance data collected from 1991 to 2000 in Matlab, Bangladesh, to estimate the spatial and temporal extent of the zone of increased risk around cholera cases. Specifically, we compare the cholera incidence among individuals living close to cholera cases with that among individuals living close to those without medically-attended cholera in this rural endemic setting.Results: : Those living within 50 m of a confirmed cholera case had 36 times (95% confidence interval: 23-56) the risk of becoming a cholera case in the first 3 days (after case presentation) compared with risk elsewhere in the community. The relative risk gradually declined in space and time, but remained significantly high up to 450 me away within 3 days of case presentation, and up to 150 m away within 23 days from the date of presentation of the case.Conclusion: : These findings suggest that, if conducted rapidly, vaccinating individuals living close to a case (ring vaccination) could be an efficient and effective strategy to target vaccine to a high-risk population in an endemic setting. [ABSTRACT FROM AUTHOR]

Background: In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Methods: Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by culture and direct fluorescent antibody techniques. The bio-physicochemical parameters of water were measured and data for cases of cholera were collected from the records of Matlab hospital. The correlation of cholera cases with levels of phytoplankton, V. cholerae and bio-physicochemical parameters of water was carried out using Pearson's correlation coefficients. Results: V. cholerae O1 survived for 48 days in association with Anabaena variabilis in a culturable state, but survived for a year in a viable but non-culturable (VBNC) state. V. cholerae survived for 12 and 32 days in a culturable state in control water (without algae) and water with algae, respectively. There was a significant correlation between changing levels of cholera cases in the community and the blue green algae and total phytoplankton in the aquatic environment. A significant correlation was also found between the cholera cases and chlorophyll-a and VBNC V. cholerae O1 in the aquatic environment. Conclusions: This study demonstrated the role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh. [ABSTRACT FROM AUTHOR]

The article discusses research which examines the immunogenicity of conjugate based on hydrazine-treated lipopolysaccharide antigen of Vibrio cholerae O139. It discusses preparation of glycoconjugate by attachment of Vibrio's hydrazine-treated lipopolysaccharide (LPS) to carboxylated bovine serum albumin (CBSA) and testing of immunological properties of the glycoconjugate by enzyme-linked immunosorbent assay, testing of anti-LPS immunoglobulins G, M and A.

Background This study describes phenotypic, genotypic and antibiotic susceptibility patterns of the strains isolated from the 2012 Sierra Leone cholera outbreak. Rectal swabs were collected from patients and cultured for Vibrio cholerae O1. Methods The isolates were subjected to multiplex PCR, mismatch amplification mutation assay (MAMA) PCR, pulsed field gel electrophoresis (PFGE), and antibiotic sensitivity tests using disk diffusion and minimum inhibitory concentration (MIC) E-test following standard procedures. Results Out of 17 rectal swabs tested, 15 yielded V. cholerae O1 biotype El Tor, serotype Ogawa. All the strains belonged to ‘altered’ variants as MAMA PCR result showed the presence of classical cholera toxin B. PFGE result revealed four pulse types. Using antibiotic disk diffusion, all the isolates were resistant to erythromycin, chloramphenicol, furazolidone, and trimethoprim/sulfamethoxazole (SXT) except SL1 which was sensitive to chloramphenicol and SXT. All the isolates were sensitive to nalidixic acid, tetracycline, doxycycline, azithromycin, and ciprofloxacin except SL2 which was resistant to nalidixic acid. However, variable sensitivity patterns were observed for kanamycin. The ranges of MIC were 0.125–0.50 mg/l, 0.003–0.023 mg/l and 0.38–0.75 mg/l for azithromycin, ciprofloxacin and tetracycline, respectively. Conclusions This study demonstrates that altered variants of V. cholerae O1 of four clonal types were responsible for the 2012 outbreak of cholera in Sierra Leone. [ABSTRACT FROM AUTHOR]

The emergence of Vibrio cholerae ( Vc) lipopolysaccharide ( LPS) as a lead protective antigen for a cholera subunit vaccine has increased the interest in what type of B cell is best suited to generate anti- Vc LPS antibodies. A related question is what form of LPS is the most immunogenic. C57 Bl/6 ( B6) neonatal mice (10 days old) whose marginal zone ( MZ) B cell compartment is still maturing and two lines of knockout mice that either lack the signaling mechanism required for the maturation of MZ B cells or that lack a receptor required for MZ B cell retention in the MZ were used to determine the role of MZ B cells in anti- Vc LPS antibody responses. Data support the conclusion that MZ B cells play a significant role in the anti- Vc LPS antibody response. Serum and vibriocidal antibody titers also depend on whether the Vc LPS is purified or bacterial cell-associated. [ABSTRACT FROM AUTHOR]

We evaluated the herd protection conferred by the bivalent killed oral cholera vaccine. The vaccine conferred significant herd protection, suggesting that significant public health impact in cholera control may be achieved even with modest vaccination coverage.Background. We evaluated the herd protection conferred by an oral cholera vaccine using 2 approaches: cluster design and geographic information system (GIS) design.Methods. Residents living in 3933 dwellings (clusters) in Kolkata, India, were cluster-randomized to receive either cholera vaccine or oral placebo. Nonpregnant residents aged ≥1 year were invited to participate in the trial. Only the first episode of cholera detected for a subject between 14 and 1095 days after a second dose was considered. In the cluster design, indirect protection was assessed by comparing the incidence of cholera among nonparticipants in vaccine clusters vs those in placebo clusters. In the GIS analysis, herd protection was assessed by evaluating association between vaccine coverage among the population residing within 250 m of the household and the occurrence of cholera in that population.Results. Among 107 347 eligible residents, 66 990 received 2 doses of either cholera vaccine or placebo. In the cluster design, the 3-year data showed significant total protection (66% protection, 95% confidence interval [CI], 50%–78%, P < .01) but no evidence of indirect protection. With the GIS approach, the risk of cholera among placebo recipients was inversely related to neighborhood-level vaccine coverage, and the trend was highly significant (P < .01). This relationship held in multivariable models that also controlled for potentially confounding demographic variables (hazard ratio, 0.94 [95% CI, .90–.98]; P < .01).Conclusions. Indirect protection was evident in analyses using the GIS approach but not the cluster design approach, likely owing to considerable transmission of cholera between clusters, which would vitiate herd protection in the cluster analyses.Clinical Trials Registration. NCT00289224. [ABSTRACT FROM PUBLISHER]