El Niño and the shifting geography of cholera in Africa.

The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases ranging from dengue to cholera. In Africa, El Niño conditions are associated with increased rainfall in East Africa and decreased rainfall in southern Africa, West Africa, and parts of the Sahel. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between ENSO patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa. Using high-resolution mapping techniques, we find that the annual geographic distribution of cholera in Africa from 2000 to 2014 changes dramatically, with the burden shifting to continental East Africa-and away from Madagascar and portions of southern, Central, and West Africa-where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall, suggesting a complex relationship between rainfall and cholera incidence. Here, we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño years, likely mediated by El Niño's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with ENSO forecasting could be used to notify countries in Africa when they are likely to see a major shift in their cholera risk.

Mapping the burden of cholera in sub-Saharan Africa and implications for control: an analysis of data across geographical scales.

BACKGROUND: Cholera remains a persistent health problem in sub-Saharan Africa and worldwide. Cholera can be controlled through appropriate water and sanitation, or by oral cholera vaccination, which provides transient (∼3 years) protection, although vaccine supplies remain scarce. We aimed to map cholera burden in sub-Saharan Africa and assess how geographical targeting could lead to more efficient interventions. METHODS: We combined information on cholera incidence in sub-Saharan Africa (excluding Djibouti and Eritrea) from 2010 to 2016 from datasets from WHO, Médecins Sans Frontières, ProMED, ReliefWeb, ministries of health, and the scientific literature. We divided the study region into 20 km × 20 km grid cells and modelled annual cholera incidence in each grid cell assuming a Poisson process adjusted for covariates and spatially correlated random effects. We combined these findings with data on population distribution to estimate the number of people living in areas of high cholera incidence (>1 case per 1000 people per year). We further estimated the reduction in cholera incidence that could be achieved by targeting cholera prevention and control interventions at areas of high cholera incidence. FINDINGS: We included 279 datasets covering 2283 locations in our analyses. In sub-Saharan Africa (excluding Djibouti and Eritrea), a mean of 141 918 cholera cases (95% credible interval [CrI] 141 538-146 505) were reported per year. 4·0% (95% CrI 1·7-16·8) of districts, home to 87·2 million people (95% CrI 60·3 million to 118·9 million), have high cholera incidence. By focusing on the highest incidence districts first, effective targeted interventions could eliminate 50% of the region's cholera by covering 35·3 million people (95% CrI 26·3 million to 62·0 million), which is less than 4% of the total population. INTERPRETATION: Although cholera occurs throughout sub-Saharan Africa, its highest incidence is concentrated in a small proportion of the continent. Prioritising high-risk areas could substantially increase the efficiency of cholera control programmes. FUNDING: The Bill & Melinda Gates Foundation.

Global Cholera Epidemiology: Opportunities to Reduce the Burden of Cholera by 2030.

While safe drinking water and advanced sanitation systems have made the Global North cholera-free for decades, the disease still affects 47 countries across the globe resulting in an estimated 2.86 million cases and 95,000 deaths per year worldwide. Cholera impacts communities already burdened by conflict, lack of infrastructure, poor health systems, and malnutrition. In October 2017, the Global Task Force on Cholera Control (GTFCC) launched an initiative titled Ending Cholera: A Global Roadmap to 2030, with the objective to reduce cholera deaths by 90% worldwide, and eliminate cholera in at least 20 countries by 2030. The GTFCC is working to position cholera control not as a vertical programme but instead using cholera as a marker of inequity and an indicator of poverty, linking the objectives of the Roadmap to the SDGs. The roadmap consists of targeted multi-sectoral interventions, supported by a coordination mechanism, along 3 axes: (1) early detection and quick response to contain outbreaks; (2) a multisectoral approach to prevent cholera recurrence in hotspots; (3) an effective partnership mechanism of coordination for technical support, countries capacity building, research and M&E, advocacy and resource mobilization. Every case and every death from cholera is preventable with the tools we have today.

Use of Vibrio cholerae vaccine in an outbreak in Guinea.

BACKGROUND: The use of vaccines to prevent and control cholera is currently under debate. Shanchol is one of the two oral cholera vaccines prequalified by the World Health Organization; however, its effectiveness under field conditions and the protection it confers in the first months after administration remain unknown. The main objective of this study was to estimate the short-term effectiveness of two doses of Shanchol used as a part of the integrated response to a cholera outbreak in Africa. METHODS: We conducted a matched case-control study in Guinea between May 20 and October 19, 2012. Suspected cholera cases were confirmed by means of a rapid test, and controls were selected among neighbors of the same age and sex as the case patients. The odds of vaccination were compared between case patients and controls in bivariate and adjusted conditional logistic-regression models. Vaccine effectiveness was calculated as (1-odds ratio)×100. RESULTS: Between June 8 and October 19, 2012, we enrolled 40 case patients and 160 controls in the study for the primary analysis. After adjustment for potentially confounding variables, vaccination with two complete doses was associated with significant protection against cholera (effectiveness, 86.6%; 95% confidence interval, 56.7 to 95.8; P=0.001). CONCLUSIONS: In this study, Shanchol was effective when used in response to a cholera outbreak in Guinea. This study provides evidence supporting the addition of vaccination as part of the response to an outbreak. It also supports the ongoing efforts to establish a cholera vaccine stockpile for emergency use, which would enhance outbreak prevention and control strategies. (Funded by Médecins sans Frontières.).

Population-Level Effect of Cholera Vaccine on Displaced Populations, South Sudan, 2014.

Following mass population displacements in South Sudan, preventive cholera vaccination campaigns were conducted in displaced persons camps before a 2014 cholera outbreak. We compare cholera transmission in vaccinated and unvaccinated areas and show vaccination likely halted transmission within vaccinated areas, illustrating the potential for oral cholera vaccine to stop cholera transmission in vulnerable populations.

Post-licensure deployment of oral cholera vaccines: a systematic review.

OBJECTIVE: To describe and analyse the characteristics of oral cholera vaccination campaigns; including location, target population, logistics, vaccine coverage and delivery costs. METHODS: We searched PubMed, the World Health Organization (WHO) website and the Cochrane database with no date or language restrictions. We contacted public health personnel, experts in the field and in ministries of health and did targeted web searches. FINDINGS: A total of 33 documents were included in the analysis. One country, Viet Nam, incorporates oral cholera vaccination into its public health programme and has administered approximately 10.9 million vaccine doses between 1997 and 2012. In addition, over 3 million doses of the two WHO pre-qualified oral cholera vaccines have been administered in more than 16 campaigns around the world between 1997 and 2014. These campaigns have either been pre-emptive or reactive and have taken place under diverse conditions, such as in refugee camps or natural disasters. Estimated two-dose coverage ranged from 46 to 88% of the target population. Approximate delivery cost per fully immunized person ranged from 0.11-3.99 United States dollars. CONCLUSION: Experience with oral cholera vaccination campaigns continues to increase. Public health officials may draw on this experience and conduct oral cholera vaccination campaigns more frequently.

Mental health and help-seeking among college students during the COVID-19 pandemic: Roles of campus mental health climate and institutional support.

Objective: This study aimed to examine college students' perceived mental health and help-seeking behaviors during the COVID-19 pandemic, as well as to determine the roles of campus mental health climate and institutional support on students' help-seeking behaviors and well-being. Participants: The sample included 123 students from a Northeastern United States University. Methods: Using a web-based survey and convenience sampling, data were collected in late 2021. Results: Most participants retrospectively reported a perceived decline in their mental health during the pandemic. Sixty-five percent of the participants reported that they did not receive professional help at a time when they needed it. Both campus mental health climate and institutional support were negatively related to anxiety symptoms. Greater institutional support predicted less social isolation. Conclusions: Our findings highlight the importance of campus climate and support on students' well-being during the pandemic and the need for increasing students' access to mental health care.

Self-criticism, self-compassion, and perceived health: moderating effect of ethnicity.

A caring and compassionate attitude toward the self (i.e., self-compassion) has been linked to various mental and physical health benefits. The Self-Compassion Scale (SCS) is widely used in psychology literature in order to assess global self-compassion. However, recent evidence suggests that the single factor model comprising positive and negative items of the SCS in fact measures two distinct constructs (i.e., self-criticism/self-coldness and self-compassion) with different psychological correlates. Given these recent findings, in addition to other research that highlights cultural differences in self-conceptualizations and self-evaluations, the present study examined potential ethnic differences in the relationships between self-criticism, self-compassion, and perceived health. Participants included 728 college students (141 Asian American, 449 European American, and 138 Hispanic/Latinx individuals) attending a university in the northeast United States. Results indicated that the relationship between self-criticism and self-compassion was significantly different across ethnicity. In addition, the relationships between these two constructs (i.e., self-criticism and self-compassion) and perceived health were moderated by ethnicity. Our findings suggest that focusing on global self-compassion scores (i.e., total SCS scores) may miss some of the important cultural or ethnic differences in the relationships between self-criticism, self-compassion, and perceived health.

COVID-19 and traumatic stress: The role of perceived vulnerability, COVID-19-related worries, and social isolation.

The purpose of the present study was to propose and test two models to understand the relationship between perceived vulnerability to COVID-19 (PVC) and COVID-19-related traumatic stress (TS), as well as the variables that may mediate and moderate this relationship among individuals who have not yet been infected with COVID-19. Using an online survey, data were collected between late March and early April 2020. Participants were recruited through Amazon Mechanical Turk and included 747 adults living in the United States. Supporting our hypotheses, results indicated that both COVID-19-related worries and social isolation were significant mediators of the relationship between PVC and TS (Model 1). In addition, the results of a moderated mediation analysis indicated that the indirect effect of PVC on TS through COVID-19-related worries was stronger for participants who reported greater social isolation (Model 2). Although future research is needed, these findings suggest that both social isolation and disease-related worries may be important variables that can be targeted in interventions to reduce pandemic-related TS.

Cholera surveillance and estimation of burden of cholera.

Cholera continues to be poorly controlled in multiple epidemic and endemic areas across the globe, with estimated annual incidence of 1.3-4.0 million cases, resulting in 21,000 to 143,000 deaths worldwide in 2015. The usual approach for patient diagnosis and cholera surveillance is clinical examination of cases of acute watery diarrhea (AWD), confirmed by positive culture or polymerase chain reaction tests. Rapid diagnostic tests (RDTs) are used in regions with limited laboratory capacities but have been found to demonstrate large variations in performance, ranging in sensitivity from 58% to 100% and in specificity from 60% to 100%. Most countries rely on hospital-based surveillance of diarrheal disease to compute the cholera burden. The World Health Organization (WHO) recommends that countries assess public health events involving cholera against the International Health Regulations 2005 criteria and determine need for official notification using the standard case definition. Cholera is an often under-recognized and under reported problem because of differences in case definitions, reluctance by authorities to acknowledge and report cholera, inadequacies in hospital surveillance systems, lack of effective diagnostic tests and commonalities in clinical presentation of cholera with other AWD etiologies. The resulting gap in burden data impairs economic analysis of disease impact and identification of areas for targeted control interventions. There is an urgent need to strengthen surveillance data by supplementing reported numbers with estimates from literature reviews and data from modelling studies, developing better-performing RDTs, enhancing monitoring and evaluation processes of in-country surveillance systems, and encouraging countries to report cholera cases by "rewarding" better reporting with technical support and improved access to vaccines. It is imperative that immediate steps are taken towards strengthening surveillance and reporting systems globally, especially in cholera-prone and resource-limited areas, where it will enable countries to articulate their demand for resources more accurately.

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines.

INTRODUCTION: Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes. METHODS: We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission. RESULTS: Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both. CONCLUSIONS: Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies.

Cholera prevention and control in Asian countries.

Cholera remains a major public health problem in many countries. Poor sanitation and inappropriate clean water supply, insufficient health literacy and community mobilization, absence of national plans and cross-border collaborations are major factors impeding optimal control of cholera in endemic countries. In March 2017, a group of experts from 10 Asian cholera-prone countries that belong to the Initiative against Diarrheal and Enteric Diseases in Africa and Asia (IDEA), together with representatives from the World Health Organization, the US National Institutes of Health, International Vaccine Institute, Agence de médecine préventive, NGOs (Save the Children) and UNICEF, met in Hanoi (Vietnam) to share progress in terms of prevention and control interventions on water, sanitation and hygiene (WASH), surveillance and oral cholera vaccine use. This paper reports on the country situation, gaps identified in terms of cholera prevention and control and strategic interventions to bridge these gaps.

Outbreak of beriberi in a prison in Côte d'Ivoire.

BACKGROUND: A beriberi outbreak occurred in the Maison d'Arrêt et de Correction d'Abidjan (MACA), a detention center in Abidjan, Côte d'Ivoire, between October 2002 and April 2003. OBJECTIVE: A retrospective investigation was conducted to document the outbreak in April 2003. METHODS: A descriptive analysis and a case-control study were performed. A probable case patient was defined as a person detained in the center between October 2002 and April 2003 with at least two of the following symptoms: bilateral leg edema, dyspnea, positive squat test, motor deficiencies, and paresthesia. A definite case patient was defined as a probable case patient who showed clinical improvement under thiamin treatment. RESULTS: Of 712 cases reported, 115 (16%) were probable and 597 (84%) were definite. The overall attack rate was 14.1%, and the case fatality rate was 1.0% (7/712). The highest attack rate was reported in the building housing prisoners with long-term sentences (16.9%). All patients were male, and the mean age was 28 years. During the period studied, the penal ration provided a fifth of the quantity of thiamin recommended by international standards. After adjustment for potential confounders, a history of cholera infection (adjusted odds ratio [OR(a)], 12.9; 95% confidence interval [CI], 2.9 to 54.1) and incarceration in the building for severe penalties (OR(a), 4.8; 95% CI, 1.3 to 18.5) were associated with the disease. CONCLUSIONS: Beriberi has been underreported among prisoners. Further attention should be given to its risk factors, especially a history of acute diarrhea. Systematic food supplementation with vitamins and micronutrients should be discussed when the penal ration does not provide the necessary nutrient intake recommended according to international standards.

Achievements and challenges for the use of killed oral cholera vaccines in the global stockpile era.

Cholera remains an important but neglected public health threat, affecting the health of the poorest populations and imposing substantial costs on public health systems. Cholera can be eliminated where access to clean water, sanitation, and satisfactory hygiene practices are sustained, but major improvements in infrastructure continue to be a distant goal. New developments and trends of cholera disease burden, the creation of affordable oral cholera vaccines (OCVs) for use in developing countries, as well as recent evidence of vaccination impact has created an increased demand for cholera vaccines. The global OCV stockpile was established in 2013 and with support from Gavi, has assisted in achieving rapid access to vaccine in emergencies. Recent WHO prequalification of a second affordable OCV supports the stockpile goals of increased availability and distribution to affected populations. It serves as an essential step toward an integrated cholera control and prevention strategy in emergency and endemic settings.

Oral cholera vaccine coverage in hard-to-reach fishermen communities after two mass Campaigns, Malawi, 2016.

CONTEXT: From December 2015 to August 2016, a large epidemic of cholera affected the fishermen of Lake Chilwa in Malawi. A first reactive Oral Cholera Vaccines (OCV) campaign was organized, in February, in a 2km radius of the lake followed by a preemptive one, conducted in November, in a 25km radius. We present the vaccine coverage reached in hard-to-reach population using simplified delivery strategies. METHOD: We conducted two-stage random-sampling cross-sectional surveys among individuals living in a 2km and 25km radius of Lake Chilwa (islands and floating homes included). Individuals aged 12months and older from Machinga and Zomba districts were sampled: 43 clusters of 14 households were surveyed. Simplified strategies were used for those living in islands and floating homes: self- delivery and community-supervised delivery of the second dose. Vaccine coverage (VC) for at-least-two-doses was estimated taking into account sampling weights and design effects. RESULTS: A total of 1176 households were surveyed (2.7% of non-response). Among the 2833 individuals living in the 2km radius of Lake and the 2915 in the 25km radius: 457 (16.1%) and 239 (8.2%) lived in floating homes or on islands at some point in the year, respectively. For the overall population, VC was 75.6% and 54.2%, respectively. In the 2km radius, VC was 92.2% for those living on the lake at some point of the year: 271 (64.8%) used the simplified strategies. The main reasons for non-vaccination were absence during the campaign and vaccine shortage. Few adverse events occurring in the 24h following vaccination was reported. CONCLUSIONS: We reached a high two-dose coverage of the most at-risk population using simplified delivery strategies. Because of the high fishermen mobility, regular catch-up campaigns or another strategy specifically targeting fishermen need to be assessed for more efficient vaccines use.

Protection against cholera from killed whole-cell oral cholera vaccines: a systematic review and meta-analysis.

BACKGROUND: Killed whole-cell oral cholera vaccines (kOCVs) are becoming a standard cholera control and prevention tool. However, vaccine efficacy and direct effectiveness estimates have varied, with differences in study design, location, follow-up duration, and vaccine composition posing challenges for public health decision making. We did a systematic review and meta-analysis to generate average estimates of kOCV efficacy and direct effectiveness from the available literature. METHODS: For this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, and the Cochrane Review Library on July 9, 2016, and ISI Web of Science on July 11, 2016, for randomised controlled trials and observational studies that reported estimates of direct protection against medically attended confirmed cholera conferred by kOCVs. We included studies published on any date in English, Spanish, French, or Chinese. We extracted from the published reports the primary efficacy and effectiveness estimates from each study and also estimates according to number of vaccine doses, duration, and age group. The main study outcome was average efficacy and direct effectiveness of two kOCV doses, which we estimated with random-effect models. This study is registered with PROSPERO, number CRD42016048232. FINDINGS: Seven trials (with 695 patients with cholera) and six observational studies (217 patients with cholera) met the inclusion criteria, with an average two-dose efficacy of 58% (95% CI 42-69, I2=58%) and effectiveness of 76% (62-85, I2=0). Average two-dose efficacy in children younger than 5 years (30% [95% CI 15-42], I2=0%) was lower than in those 5 years or older (64% [58-70], I2=0%; p<0·0001). Two-dose efficacy estimates of kOCV were similar during the first 2 years after vaccination, with estimates of 56% (95% CI 42-66, I2=45%) in the first year and 59% (49-67, I2=0) in the second year. The efficacy reduced to 39% (13 to 57, I2=48%) in the third year, and 26% (-46 to 63, I2=74%) in the fourth year. INTERPRETATION: Two kOCV doses provide protection against cholera for at least 3 years. One kOCV dose provides at least short-term protection, which has important implications for outbreak management. kOCVs are effective tools for cholera control. FUNDING: The Bill & Melinda Gates Foundation.