Cholera In Africa Research Articles

Evaluation of cholera surveillance systems in Africa: a systematic review.

Despite several interventions on the control of cholera, it still remains a significant public health problem in Africa. According to the World Health Organization, 251,549 cases and 4,180 deaths (CFR: 2.9%) were reported from 19 African countries in 2023. Tools exist to enhance the surveillance of cholera but there is limited evidence on their deployment and application. There is limited evidence on the harmonization of the deployment of tools for the evaluation of cholera surveillance. We systematically reviewed available literature on the deployment of these tools in the evaluation of surveillance systems in Africa. Three electronic databases (PubMed, Medline and Embase) were used to search articles published in English between January 2012 to May 2023. Grey literature was also searched using Google and Google Scholar. Only articles that addressed a framework used in cholera surveillance in Africa were included. The quality of articles was assessed using the appropriate tools. Data on the use of surveillance tools and frameworks were extracted from articles for a coherent synthesis on their deployment. A total of 13 records (5 frameworks and 8 studies) were fit for use for this study. As per the time of the study, there were no surveillance frameworks specific for the evaluation of surveillance systems of cholera in Africa, however, five frameworks for communicable diseases and public health events could be adapted for cholera surveillance evaluation. None (0%) of the studies evaluated capacities on cross border surveillance, multisectoral one health approach and linkage of laboratory networks to surveillance systems. All (100%) studies assessed surveillance attributes even though there was no synergy in the attributes considered even among studies with similar objectives. There is therefore the need for stakeholders to harmoniously identify a spectrum of critical parameters and attributes to guide the assessment of cholera surveillance system performance.

Cholera rages in Africa and the Middle East: A narrative review on challenges and solutions.

Cholera is a life-threatening infectious disease that is still one of the most common acute watery diarrheal diseases in the world today. Acute diarrhea and severe dehydration brought on by cholera can cause hypovolemic shock, which can be fatal in minutes. Without competent clinical therapy, the rate of case fatality surpasses 50%. The purpose of this review was to highlight cholera challenges in Africa and the Middle East and explain the reasons for why this region is currently a fertile environment for cholera. We investigated cholera serology, epidemiology, and the geographical distribution of cholera in Africa and the Middle East in 2022 and 2023. We reviewed detection methods, such as rapid diagnostic tests (RDTs), and treatments, such as antibiotics and phage therapy. Finally, this review explored oral cholera vaccines (OCVs), and the vaccine shortage crisis. We carried out a systematic search in multiple databases, including PubMed, Web of Science, Google Scholar, Scopus, MEDLINE, and Embase, for studies on cholera using the following keywords: ((Cholera) OR (Vibrio cholera) and (Coronavirus) OR (COVID-19) OR (SARS-CoV2) OR (The Middle East) OR (Africa)). Cholera outbreaks have increased dramatically, mainly in Africa and many Middle Eastern countries. The COVID-19 pandemic has reduced the attention devoted to cholera and disrupted diagnosis and treatment services, as well as vaccination initiatives. Most of the cholera cases in Africa and the Middle East were reported in Malawi and Syria, respectively, in 2022. RDTs are effective in the early detection of cholera epidemics, especially with limited advanced resources, which is the case in much of Africa. By offering both direct and indirect protection, expanding the use of OCV will significantly reduce the burden of current cholera outbreaks in Africa and the Middle East.

The surging cholera epidemic in Africa: a review of the current epidemiology, challenges and strategies for control

Africa, a known region with abundant warm coastal waters and a natural reservoir for Vibrio cholera, is known to bear the highest burden of cholera morbidity and mortality globally. Malawi is currently experiencing the deadliest cholera outbreak in two decades, and neighbouring countries, Mozambique and Zambia, have also reported significant numbers of cases. If the current trend of cholera transmission is sustained, the number of fatalities recorded in 2021, Africa’s deadliest year for cholera over the past decade, might be exceeded. This article aims to review the current epidemiology, prevention and control strategies, and treatment of cholera in Africa to highlight context-specific challenges and recommend possible solutions. The authors found out that cholera outbreaks in Africa are taking place in the midst of epidemics (measles, mumps, etc.) and natural disasters like cyclones and flooding (Mozambique, Malawi), drought (Kenya, and Ethiopia), and conflict (Cameroon, the DR Congo, Nigeria, and Ethiopia). The shortages of medical supplies like cholera kits and oral cholera vaccines in many countries due to constrained and limited resources and antibiotic resistance further make management and control difficult. The outbreak is spreading throughout the region because of poor sanitation, unsafe water supplies, and increased cross-border travel. Cholera in Africa follows a seasonal pattern, suggesting specific periods for heightened outbreak preparedness and response. The authors suggest a targeted multisectorial approach and a coordinated mechanism to respond to the epidemic through sustained political will, formidable partnerships, resource mobilisation, and the provision of technical support and advocacy at sub-national, national, and international levels.

Cholera resurgence in Africa: assessing progress, challenges, and public health response towards the 2030 global elimination target.

Global efforts to combat epidemic cholera outbreaks have witnessed tremendous feats over the decades. However, sporadic outbreaks in regions, particularly across African states, mask these advancements. This regressive trend is frequently fuelled by factors retarding efforts towards optimal environmental sanitation and personal hygiene, which include ingesting infected food, drinking contaminated waters, and engaging in unhealthy environmental practices such as indiscriminate waste and sewage disposal and poor toilet practices. The ongoing efforts to achieve the Global Taskforce on Cholera Control (GTFCC) targets of a 90% reduction in cases and deaths by 2030, even in the wake of continuous outbreaks across various African regions, as reported by the World Health Organization (WHO) face a significant threat. One such effort, among others, is the AFRICHOL project, an enhanced cholera surveillance consortium launched in Africa over a decade ago as part of the GTFCC at WHO to monitor and fast-track the GTFCC's 2030 targets. It is tasked with supporting the implementation of research-based strategies for combating cholera in Africa. The prequalified oral cholera vaccines - Dukoral, Shanchol, and Euvichol - and those with recombinant DNA technology have also emerged as remarkable strides. In the face of this progress, challenges persist. Climate change, including extreme weather events and the lack of safe water, sanitation, and hygiene facilities, acts as a multiplier, amplifying existing challenges and hindering progress. Porous borders with inefficient disease surveillance networks among member states also facilitate the inter-territorial spread of the disease. Despite ongoing challenges, global targets are achievable provided strong institutional infrastructure and additional evidence-based public health initiatives are promulgated and enacted. The Global Roadmap to Ending Cholera Outbreaks by 2030 is a resourceful tool for advancing this fight and eradicating cholera.

The Threat of Cholera in Africa

A multi-country cholera outbreak has occurred in several developing countries in Africa, Asia and Oceania since mid-2021. The current multi-country cholera outbreak has spread primarily in Africa. As of February 2023, cholera cases have been reported in approximately 25 countries, 15 (60%) of which are in sub-Saharan Africa. According to the World Health Organization, 547,626 confirmed cases and 4,927 total deaths were recorded until August 2023. Of these, approximately 33.68% cases (184,474) and 64.2% deaths (3,165) occurred in African countries, and the number may increase in the coming months. Although various organizations and local administrations have made response efforts, the response capacity for multiple outbreaks is insufficient, and the outbreak has been exacerbated by a global lack of resources, cholera vaccine shortages, climatic effects, a lack of supplies and the occurrence of other health emergencies. Herein, the rapid review method was used, with emphasis on available and recent global information found in Google Scholar, PubMed and data publicly available from websites. This review article provides current alert information regarding the broad spread and upsurge characteristics of the ongoing cholera outbreak.

Accessing sub-national cholera epidemiological data for Nigeria and the Democratic Republic of Congo during the seventh pandemic

BackgroundVibrio cholerae is a water-borne pathogen with a global burden estimate at 1.4 to 4.0 million annual cases. Over 94% of these cases are reported in Africa and more research is needed to understand cholera dynamics in the region. Cholera data are lacking, mainly due to reporting issues, creating barriers for widespread research on cholera epidemiology and management in Africa.Main bodyHere, we present datasets that were created to help address this gap, collating freely available sub-national cholera data for Nigeria and the Democratic Republic of Congo. The data were collated from a variety of English and French publicly available sources, including the World Health Organization, PubMed, UNICEF, EM-DAT, the Nigerian CDC and peer-reviewed literature. These data include information on cases, deaths, age, gender, oral cholera vaccination, risk factors and interventions.ConclusionThese datasets can facilitate qualitative, quantitative and mixed methods research in these two high burden countries to assist in public health planning. The data can be used in collaboration with organisations in the two countries, which have also collected data or undertaking research. By making the data and methods available, we aim to encourage their use and further data collection and compilation to help improve the data gaps for cholera in Africa.

Exploring relationships between drought and epidemic cholera in Africa using generalised linear models

BackgroundTemperature and precipitation are known to affect Vibrio cholerae outbreaks. Despite this, the impact of drought on outbreaks has been largely understudied. Africa is both drought and cholera prone and more research is needed in Africa to understand cholera dynamics in relation to drought.MethodsHere, we analyse a range of environmental and socioeconomic covariates and fit generalised linear models to publicly available national data, to test for associations with several indices of drought and make cholera outbreak projections to 2070 under three scenarios of global change, reflecting varying trajectories of CO2 emissions, socio-economic development, and population growth.ResultsThe best-fit model implies that drought is a significant risk factor for African cholera outbreaks, alongside positive effects of population, temperature and poverty and a negative effect of freshwater withdrawal. The projections show that following stringent emissions pathways and expanding sustainable development may reduce cholera outbreak occurrence in Africa, although these changes were spatially heterogeneous.ConclusionsDespite an effect of drought in explaining recent cholera outbreaks, future projections highlighted the potential for sustainable development gains to offset drought-related impacts on cholera risk. Future work should build on this research investigating the impacts of drought on cholera on a finer spatial scale and potential non-linear relationships, especially in high-burden countries which saw little cholera change in the scenario analysis.

Model-based estimation of the economic burden of cholera in Africa

ObjectivesTo estimate the economic burden of cholera in Africa.SettingsCholera affected 44 countries in Africa.ParticipantsThe analysis used data from public sources in Africa published until September 2019.MethodsBased on existing data from...

Systematic Study and Meta-Analysis of Risk Factors Associated with Cholera Outbreaks in Africa: A Review

In Sub-Saharan Africa, cholera is a persistent public health problem. Various methods are now being applied to reduce the mobility and mortality that these diseases cause. Because of the implemented policies, there seem to have been several improvements. However, the constraints suggest inefficiency in eliminating the burden, necessitating a straightforward explanation. The systematic review and meta-analysis aimed are to investigate the reasons for the incomplete eradication of cholera disease in Sub-Saharan Africa. We were able to obtain pooled estimates using random effect models. Four experiments were excluded from the study because they were duplicated in the studies, 13 because of an outbreak did not occur, 13 publications did not include risk factors and odds ratios in their outcome analysis, and an outbreak occurred before 2013. The review points out that drinking contaminated water, consuming unwashed vegetables, and the use of poor publish toilet facilities enhance cholera in Africa. PubMed, Web of Science, EMBASE, and EBSCO were among the four meticulously and systematically searched databases using predetermined criteria or search strategies. Two independent reviewers recognized studies that met the selection criteria, and data was collected using validated methods.

Genomic insights into Vibrio cholerae O1 responsible for cholera epidemics in Tanzania between 1993 and 2017.

BackgroundTanzania is one of seven countries with the highest disease burden caused by cholera in Africa. We studied the evolution of Vibrio cholerae O1 isolated in Tanzania during the past three decades.Methodology/Principal findingsGenome-wide analysis was performed to characterize V. cholerae O1 responsible for the Tanzanian 2015–2017 outbreak along with strains causing outbreaks in the country for the past three decades. The genomes were further analyzed in a global context of 590 strains of the seventh cholera pandemic (7PET), as well as environmental isolates from Lake Victoria. All Tanzanian cholera outbreaks were caused by the 7PET lineage. The T5 sub-lineage (ctxB3) dominated outbreaks until 1997, followed by the T10 atypical El Tor (ctxB1) up to 2015, which were replaced by the T13 atypical El Tor of the current third wave (ctxB7) causing most cholera outbreaks until 2017 with T13 being phylogenetically related to strains from East African countries, Yemen and Lake Victoria. The strains were less drug resistant with approximate 10-kb deletions found in the SXT element, which encodes resistance to sulfamethoxazole and trimethoprim. Nucleotide deletions were observed in the CTX prophage of some strains, which warrants further virulence studies. Outbreak strains share 90% of core genes with V. cholerae O1 from Lake Victoria with as low as three SNPs difference and a significantly similar accessory genome, composed of genomic islands namely the CTX prophage, Vibrio Pathogenicity Islands; toxin co-regulated pilus biosynthesis proteins and the SXT-ICE element.Conclusion/SignificanceCharacterization of V. cholerae O1 from Tanzania reveals genetic diversity of the 7PET lineage composed of T5, T10 and T13 sub-lineages with introductions of new sequence types from neighboring countries. The presence of these sub-lineages in environmental isolates suggests that the African Great Lakes may serve as aquatic reservoirs for survival of V. cholerae O1 favoring continuous human exposure.

The Beginning of the End for Cholera in Africa

The Beginning of the End for Cholera in Africa

The Beginning of the End for Cholera in Africa

The Beginning of the End for Cholera in Africa

Recurrent cholera epidemics in Africa: which way forward? A literature review.

Outbreaks of cholera in Africa seem to be unrelenting which has been continuous and recurrent leading to high morbidity and mortality in some quarters. The objective of this narrative review is to investigate and identify factors responsible for the recurrent outbreaks of cholera in Africa and response strategies that have been employed in curbing the problem, with the view of aggregating otherwise sparing data needed for policy formulation geared towards control and eradication of the disease. Search of literatures indexed in Google Scholar, PubMed and AJOL databases was carried out. Sixty-five eligible articles with reports on the risk factors that drive recurrent outbreaks, endemicity and response strategies were analyzed. Our findings indicate that continuous and recurrent outbreaks of cholera in Africa are fueled by cross-border migration, environmental reservoirs, socioeconomic factors, climate change and political instability. The review also identified specific response strategies and modelling approaches that have helped in containing and reducing the impact of these outbreaks. Paying attention and tackling these identified factors that are dependent and independent can help put an end to this running battle.

Sensitivity, Specificity, and Public-Health Utility of Clinical Case Definitions Based on the Signs and Symptoms of Cholera in Africa.

.During 2014, Africa reported more than half of the global suspected cholera cases. Based on the data collected from seven countries in the African Cholera Surveillance Network (Africhol), we assessed the sensitivity, specificity, and positive and negative predictive values of clinical cholera case definitions, including that recommended by the World Health Organization (WHO) using culture confirmation as the gold standard. The study was designed to assess results in real-world field situations in settings with recent cholera outbreaks or endemicity. From June 2011 to July 2015, a total of 5,084 persons with suspected cholera were tested for Vibrio cholerae in seven different countries of which 35.7% had culture confirmation. For all countries combined, the WHO case definition had a sensitivity = 92.7%, specificity = 8.1%, positive predictive value = 36.1%, and negative predictive value = 66.6%. Adding dehydration, vomiting, or rice water stools to the case definition could increase the specificity without a substantial decrease in sensitivity. Future studies could further refine our findings primarily by using more sensitive methods for cholera confirmation.

Genomic history of the seventh pandemic of cholera in Africa.

The seventh cholera pandemic has heavily affected Africa, although the origin and continental spread of the disease remain undefined. We used genomic data from 1070 Vibrio cholerae O1 isolates, across 45 African countries and over a 49-year period, to show that past epidemics were attributable to a single expanded lineage. This lineage was introduced at least 11 times since 1970, into two main regions, West Africa and East/Southern Africa, causing epidemics that lasted up to 28 years. The last five introductions into Africa, all from Asia, involved multidrug-resistant sublineages that replaced antibiotic-susceptible sublineages after 2000. This phylogenetic framework describes the periodicity of lineage introduction and the stable routes of cholera spread, which should inform the rational design of control measures for cholera in Africa.

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.

Cholera in Africa: new momentum in fighting an old problem.

Cholera remains a grave public health problem in Africa. It is endemic with seasonal variations around the central African Great Lakes. Along the coasts, it occurs mostly in rapidly expanding epidemics, with intercalated 3-5 year lull-periods. Case-fatality ratios remain high at 2–5% against the global declining trend. Insufficient safe water and sanitation coverage are the main causes of persistent cholera in Africa and this is unlikely to improve soon. However, an efficacious oral cholera vaccine is now available and new groups and initiatives like the African Cholera Surveillance Network (Africhol) allow countries to enhance their capacities for an integrated cross-border approach using all means necessary to tackle cholera in Africa.

Planning for the elimination of cholera: An example of integrated national plan

In the early nineteenth century, the first recorded cholera outbreaks occurred in South-East Asia,with thefirst six pandemics and the seventh ongoing cholera pandemic. After the major outbreaks of the mid-nineteenth century, cholera was completely eliminated in Europe. In Africa however significant cholera outbreaks have only been reported since 1970, and ifwe consider the cases reported byWHO, it one of the most affected regions of the world. Cholera remains one of the most important public health issues in theDemocraticRepublic of Congo (DRC). Since1977, a succession of outbreaks has occurred, seemingly without spatial or temporal logic. The change of the 1970-1990’s epidemic profile to the current endemic profile is in contrast with the dispersion, with no clear logic and weak operational strategies. An extensive research project has been conducted since 2005 in order to better understand the spatial and temporal dynamics of cholera in the DRC and suggest adjustments to operational strategies. The objective of this study has been to emphasize multidisciplinary approaches and to analyze the series of cholera cases over the long-term. The study showed evidence of the persistence and recurrence of cholera epidemics during the dry season around the small lakes areas. These cholera ‘sanctuaries areas’ were identified through the detection of the seasonality of epidemics around the lake areas. The evidence suggests that targeting the ‘sanctuaries areas’ located in the African Great Lake Region should be a priority in the cholera elimination plan in the DRC. Based on the results and the recommendations of this work, the DRC has adopted the 2013-2017 Multisectorial Plan to Eliminate Cholera as a public health issue. Using epidemiological monitoring combined with an understanding of the dynamics of the disease to complete the adjustment of operational approaches shouldmotivate other countries inAfrica where cholera remains a real public health issue. The elimination of cholera in Africa is possible. But in order for this to occur, cholera should be moved out of the perpetual emergency reaction cycle. Local actors need to be empowered and the international community has to agree to join and support that objective.

The Role of Vibrio cholerae Genotyping in Africa

Toxigenic Vibrio cholerae, the causative agent of the disease cholera, is prevalent in the African continent from the 1970s when the seventh pandemic spread from Asia to Africa. In the past decade, cholera has caused devastating outbreaks in much of Africa, illustrated by the recent cholera epidemics in Zimbabwe and regions of central Africa. Given the extent of cholera in Africa, a robust and efficient surveillance system should be in place to prevent and control the disease in this continent. Such a surveillance system would be greatly bolstered by use of molecular typing techniques to identify genetic subtypes. In this review, we highlight the role that modern molecular typing techniques can play in tracking and aborting the spread of cholera.

Editorial Committee Introduction

The current supplement presents an overview of cholera disease burden and critical issues for the diagnosis, detection, prevention, and control of cholera in Africa. In 2013, the seventh cholera pandemic reached its 43rd year in Africa, with no evidence that it will end soon. More than 20 African countries have reported cholera to the World Health Organization (WHO) every year between 2007 and 2012, including large recent epidemics in the Democratic Republic of Congo (DRC), Sierra Leone, Uganda, Ghana, Niger, and Guinea [1].