Cholera prevention, control strategies, challenges and World Health Organization initiatives in the Eastern Mediterranean Region: A narrative review

Cholera resurges in Zambia: Challenges and future directions

Cholera remains a major global health challenge, disproportionately affecting low-income countries with inadequate water, sanitation, and hygiene (WASH) infrastructure. Zambia, historically prone to outbreaks, experienced a severe resurgence in 2023-2024, with over 10,887 cases and 432 deaths. The contributing factors include poor WASH access, systemic health care weaknesses, stigma, and logistical barriers. Only 32% of households have basic water services, and health care worker shortages persist, especially in densely populated areas. Misinformation and cultural practices hinder public health efforts, whereas fiscal constraints limit prevention strategies. Strengthening epidemic preparedness through WASH investments, systems thinking, predictive modeling, artificial intelligence-driven surveillance, and multi-sectoral approach integrating community engagement and health system resilience is essential to mitigate the outbreak. This commentary explores Zambia's cholera control challenges and outlines strategic directions for a resilient, sustainable response to this enduring public health threat.

Vibrio cholerae: Understanding a persistent pathogen in Sub-Saharan Africa and the East Mediterranean Region

Vibrio cholerae remains a significant public health threat in Sub-Saharan Africa and the East Mediterranean Region, where recurrent outbreaks are driven by inadequate water, sanitation, and hygiene infrastructure, climatic variability, and socio-political instability. This review explores the persistence of the pathogen in these regions, examining its epidemiology, environmental reservoirs, and genomic adaptations that enhance its survival and transmission. We highlight the impact of antimicrobial resistance and the role of climate change in cholera dynamics. Furthermore, we discuss current prevention and control strategies, including advancements in oral cholera vaccines, genomic surveillance, and microbiome-targeted interventions. Addressing these challenges requires a multifaceted approach that integrates sustainable sanitation improvements, strengthened disease surveillance, and innovative vaccination strategies. Understanding the persistence of V. cholerae in these high-risk regions is critical for developing effective, long-term mitigation strategies to reduce cholera morbidity and mortality.

An assessment of the progress made in the implementation of the regional framework for cholera prevention and control in the WHO African region

High-burden cholera outbreaks, spreading beyond the traditional cholera-endemic countries, have been reported since 2021 in the WHO African region. Member states in the region have committed to the global goal of cholera elimination by 2030. To track progress towards this goal, WHO-African countries adopted a regional cholera prevention and control framework in 2018. This study reports on 27 countries' 5-year achievements in implementing the cholera regional framework for cholera prevention, and control. Data collected through a web-based self-assessment tool were analysed and visualised through Power BI. Data were provided by national teams of experts on cholera based on the milestones of the framework. Countries' specific progress and regional progress were calculated. The overall regional progress was 53%, ranging from 19% in Mauritania to 76% in Ethiopia. Out of the 27 countries, 3 had made good progress while 14 had fair and 10 had insufficient progress. At the regional level, 4 milestones were on track, 7 were fair and 10 had insufficient progress. Cholera hot spot mapping had the highest score at 85%, while development of investment cases for cholera control scored the lowest at 14%. Although appreciable progress was noted in some milestones, the progress against critical milestones, including for water, sanitation and hygiene, that form the bedrock of cholera control, was insufficient. Effective implementation of the cholera prevention and control framework anchored on strong government commitment and ownership is essential to curb the current trend of cholera outbreaks and improve the likelihood of cholera elimination by 2030 in Africa.

Building resilience against cholera: lessons from the implementation of integrated community strategy for cholera control in Zambia

Cholera has remained a persistent public health challenge in Zambia since the country's first reported outbreak in 1977. The recent outbreak, which began in October 2023 and is ongoing as of June 2024, is the most severe in Zambia's history and part of the larger 2022-2024 Southern Africa cholera outbreak, which has affected multiple countries in the region. This article describes the implementation of the integrated community strategy for cholera control (ICSCC) in three districts of the Copperbelt Province during this outbreak. The ICSCC is a comprehensive, community-centric public health approach that integrates surveillance, case management, water, sanitation and hygiene interventions, community engagement and infection prevention measures. The strategy's implementation involved deploying multidisciplinary technical teams, training community-based volunteers and healthcare workers in the affected communities. This approach led to a rapid reduction in cholera cases and mortality, largely due to enhanced surveillance, community education sessions and improved sanitation practices. The ICSCC also improved stakeholder coordination and enabled rapid communication for early response to cholera hotspots. Key lessons learnt include the importance of robust coordination, early community involvement and context-specific adaptations. The strategy's emphasis on data-driven decision-making and adaptation to local socio-cultural dynamics was crucial for its effectiveness. These findings underscore the potential of integrated community-based approaches in managing cholera outbreaks, enhancing public health preparedness and building long-term resilience. The ICSCC strategy offers a scalable model for regions facing similar public health challenges, providing valuable insights for policymakers and practitioners on the effectiveness of community involvement in managing public health crises.

Improved cholera control in Kenya: A retrospective analysis of 2017-2019 in Nairobi and Homabay

Background

Kenya has recorded at least 38 678 cases and 695 deaths over the last decade, and costing on average $2.2 million annually. From 2014 to 2016, the country experienced one of the deadliest and largest outbreak. However, between 2017 and 2020, there was a decline in the number of reported cases and deaths.

Aim

This study seeks to reveal the investments made post the 2014-2016 outbreak and highlight existing gaps that need to be addressed to stop the resurgence of cholera outbreaks in Kenya.

Setting

The study was conducted in two counties: Homabay and Nairobi.

Methods

We used an observational study. Data were collected from 20 health facilities (involved in cholera control, during the study), 9 key informant interviews (KII) and 6 focus group discussions (FGDs).

Results

We found improvement such as: dissemination of standard operating procedures, aligned reporting system, field epidemiology programme, establishment of a public health emergency operating centre and improved partner coordination. On the other hand, 12 of the selected 20 (60%) facilities had no prior training before government financing and laboratory capacity was sub-optimal: 13 (65%) facilities had no prior training, 16 (20%) had no operational laboratory plan and 10 (50%) had inadequate laboratory test kits and reagents.

Conclusion

This study highlights that Kenya has experienced an improvement in specific core capacities.

Contribution

For Kenya to completely flatten the curve, there is need for more sustainable investment and government's commitment in health system strengthening.

Antibacterial and antibiofilm features of mutSMAP-18 against Vibrio cholerae

Cholera continues to be a pointed global health issue, prominently in developing nations, where the disease's severe diarrheal symptoms pose substantial public health risks. With the escalating spread of antibiotic resistance among V. cholerae strains, alternative therapeutic approaches are imperative. Antimicrobial peptides are increasingly recognized for their potential, with research focusing on finding the most effective options. We explored the antibacterial and antibiofilm properties of analogues of sheep myeloid antimicrobial peptide-18 (SMAP-18) against V. cholerae in this investigation. Our prior research demonstrated that substituting glycine with alanine at different positions within SMAP-18 altered its structure and antimicrobial activity. Among these altered analogues, our focus was on a mutant variant (mutSMAP-18), characterized by glycine-to-alanine substitutions at positions 2, 7, and 13. Our results indicated that mutSMAP-18 exhibited heightened antimicrobial and antibiofilm activities against V. cholerae compared to SMAP-18. We conducted several mechanistic investigations to check the membrane integrity using DNA-binding dye, SYTOX Green or measuring calcein dye leakage and analyzing flow cytometry by fluorescence-activated cell sorting (FACScan). From these tests, we elucidated that SMAP-18 primarily functions intracellularly, while mutSMAP-18 targets the bacterial membrane. Additionally, scanning electron microscopy (SEM) images illustrated membrane disruption at lower concentrations for mutSMAP-18. Notably, mutSMAP-18 demonstrated significant antibiofilm properties against V. cholerae. Overall, these findings offer valuable perspectives for developing novel antibacterial therapies targeting the pathogenic V. cholerae.

Biological Characterization and Evaluation of the Therapeutic Value of Vibrio Phages 4141 and MJW Isolated from Clinical and Sewage Water Samples of Kolkata

The growing prevalence of antimicrobial resistance (AMR) necessitates the development of new treatment methods to combat diseases like cholera. Lytic bacteriophages are viruses that specifically target and lyse bacteria upon infection, making them a possible treatment option for multi-drug-resistant pathogens. The current study investigated the potential role of bacteriophages isolated from clinical stool and sewage water samples in treating multi-drug-resistant Vibrio cholerae infection, finding that over 95% of the strains were susceptible. Whole-genome sequencing (WGS) analysis revealed that both Vibrio phage 4141 (4141) and Vibrio phage MJW (MJW) contain double-stranded DNA genomes consisting of 38,498 bp (43% GC) and 49,880 bp (42.5% GC) with 46 and 64 open reading frames (ORFs), respectively. Transmission electron microscope (TEM) and WGS analysis of Vibrio phage 4141 and Vibrio phage MJW validated that they are classified under the family Autographiviridae and Zobellviridae, respectively. Furthermore, both the phages showed highly significant biofilm degradation properties. The characterization of the phages and their strict host range, high spectrum of lytic ability, high efficiency of biofilm degradation, and close genetic similarity to the therapeutic phages indicates that these phages may be useful for therapeutic purposes for treating MDR V. cholerae infection in the future.

Spotlight on the epidemiology and antimicrobial susceptibility profiles of Vibrio species in the MENA region, 2000-2023

Recent cholera outbreaks in many countries in the Middle East and North Africa (MENA) region have raised public health concerns and focused attention on the genus Vibrio. However, the epidemiology of Vibrio species in humans, water, and seafood is often anecdotal in this region. In this review, we screened the literature and provided a comprehensive assessment of the distribution and antibiotic resistance properties of Vibrio species in different clinical and environmental samples in the region. This review will contribute to understanding closely the real burden of Vibrio species and the spread of antibiotic-resistant strains in the MENA region. The overall objective is to engage epidemiologists, sanitarians and public health stakeholders to address this problem under the One-health ethos.

Multiple endemic equilibria in an environmentally-transmitted disease with three disease stages

We construct, analyze and interpret a mathematical model for an environmental transmitted disease characterized for the existence of three disease stages: acute, severe and asymptomatic. Besides, we consider that severe and asymptomatic cases may present relapse between them. Transmission dynamics driven by the contact rates only occurs when a parameter R∗>1, as normally occur in directly-transmitted or vector-transmitted diseases, but it will not adequately correspond to a basic reproductive number as it depends on environmental parameters. In this case, the forward transcritical bifurcation that exists for R∗<1, becomes a backward bifurcation, producing multiple steady-states, a hysteresis effect and dependence on initial conditions. A threshold parameter for an epidemic outbreak, independent of R∗ is only the ratio of the external contamination inflow shedding rate to the environmental clearance rate. R∗ describes the strength of the transmission to infectious classes other than the I-(acute) type infections. The epidemic outbreak conditions and the structure of R∗ appearing in this model are both responsible for the existence of endemic states.

Attitude towards cholera vaccination and its related factors in Jordan amid the 2022 Middle East outbreak

BACKGROUND

An outbreak of cholera was reported in the Middle East by the second half of 2022. Raising public awareness and vaccination against cholera represent critical factors in the preventive efforts. The current study aimed to assess the knowledge of cholera and attitude towards its vaccination among a sample of the general public residing in Jordan.

METHODS

An online self-administered questionnaire was distributed to the residents in Jordan using a snowball convenience-based sampling approach. The questionnaire based on previously published studies included items to evaluate sociodemographic variables, knowledge about cholera symptoms, transmission, and prevention and the willingness to accept cholera vaccination. Additionally, four items based on the validated 5 C scale in Arabic were included to assess the psychological factors influencing attitude to cholera vaccination.

RESULTS

The final study sample comprised 1339 respondents, of whom 1216 (90.8%) heard of cholera before the study. Among those who heard of cholera, and on a scale from 0 to 20, the overall mean cholera Knowledge score (K-score) was 12.9 ± 3.8. In multivariate analysis, being over 30 years old and occupation as healthcare workers or students in healthcare-related colleges were significantly associated with a higher K-score compared to younger individuals and students in non-healthcare-related colleges. Overall, the acceptance of cholera vaccination if cases are recorded in Jordan, and if the vaccine is safe, effective, and provided freely was reported among 842 participants (69.2%), while 253 participants were hesitant (20.8%) and 121 participants were resistant (10.0%). In linear regression, the significant predictors of cholera vaccine acceptance were solely the three psychological factors namely high confidence, low constraints, and high collective responsibility.

CONCLUSIONS

In this study, the identified gaps in cholera knowledge emphasize the need to enhance educational initiatives. Although cholera vaccine acceptance was relatively high, a significant minority of the respondents exhibited vaccination hesitancy or resistance. The evident correlation between the psychological determinants and attitudes toward cholera vaccination emphasizes the need to consider these factors upon designing public health campaigns aimed at cholera prevention. The insights of the current study highlight the importance of addressing both knowledge gaps and psychological barriers to optimize cholera control strategies.

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.

Multisectoral approach for the control of cholera outbreak - lessons and challenges from Lusaka district - Zambia, October 2023 - February 2024

Introduction

on October 18, 2023, the Ministry of Health declared an outbreak of cholera in the Lusaka district. Public health interventions were implemented using a multisectoral approach in the Lusaka district and other hotspots in the country. We documented the multisectoral response efforts and their impacts on the cholera epidemic in the Lusaka district of Zambia. We highlighted the major challenges and their associated impacts on the epidemiologic patterns of disease in hotspot areas.

Methods

we conducted a descriptive observational study of cholera response activities in the Lusaka district. We used quantitative and qualitative non-participant techniques using the Centers for Disease Prevention and Control's direct in-person observation tool in healthcare settings. We reviewed surveillance records to estimate the magnitude of the outbreak, and characterized cases by person, place, and time. We documented the response interventions and challenges using situation reports.

Results

during the 2023 - 2024 cholera outbreak, Lusaka district was the most affected district with 13,122 cases and 498 deaths as of 12th February 2024. Despite having a well-established system for coordinating technical support and resource mobilization, inadequate sanitation and limited access to clean water remained potential risks for cholera outbreaks in Lusaka district.

Conclusion

Lusaka district may have experienced one of the most severe cholera epidemics in the nation's history, as indicated by its rapid spread and increased mortality reported from both the community and treatment centers. A multisectoral coordination for improved sanitary systems, access to clean water, health education strategies, and vaccination campaigns contributed to the decline in cholera cases.

Mathematical modeling of cholera dynamics with intrinsic growth considering constant interventions

A mathematical model that describes the dynamics of bacterium vibrio cholera within a fixed population considering intrinsic bacteria growth, therapeutic treatment, sanitation and vaccination rates is developed. The developed mathematical model is validated against real cholera data. A sensitivity analysis of some of the model parameters is also conducted. The intervention rates are found to be very important parameters in reducing the values of the basic reproduction number. The existence and stability of equilibrium solutions to the mathematical model are also carried out using analytical methods. The effect of some model parameters on the stability of equilibrium solutions, number of infected individuals, number of susceptible individuals and bacteria density is rigorously analyzed. One very important finding of this research work is that keeping the vaccination rate fixed and varying the treatment and sanitation rates provide a rapid decline of infection. The fourth order Runge-Kutta numerical scheme is implemented in MATLAB to generate the numerical solutions.

Butyrate affects bacterial virulence: a new perspective on preventing enteric bacterial pathogen invasion

Enteric bacterial pathogens are a major threat to intestinal health. With the widespread use of antibiotics, bacterial resistance has become a problem, and there is an urgent need for a new treatment to reduce dependence on antibiotics. Butyrate can control enteric bacterial pathogens by regulating the expression of their virulence genes, promoting the posttranslational modification of their proteins, maintaining an anaerobic environment, regulating the host immune system and strengthening the intestinal mucosal barrier. Here, this review describes the mechanisms by which butyrate regulates the pathogenicity of enteric bacterial pathogens from various perspectives and discusses the prospects and limitations of butyrate as a new option for the control of pathogenic bacteria.

The Chronic Cholera Situation in Africa: Why Are African Countries Unable to Tame the Well-Known Lion?

Seven years to the Global Taskforce on Cholera Control's target of reducing cholera cases and deaths by 90% by 2030, Africa continues to experience a high incidence of the disease. In the last 20 years, more than 2.6 million cases and 60 000 deaths of the disease have been recorded, mostly in sub-Saharan Africa. Case Fatality Ratio remains consistently above the WHO-recommended 1% with a yearly average of 2.2%. Between 1 January 2022 and 16 July 2023, fourteen African countries reported 213 443 cases and 3951 deaths (CFR, 1.9%) of the disease. In this perspective article, based on available literature and the authors' field experiences in Africa, we discuss the underlying reasons for the sustained transmission of the disease. We posit that in addition to the well-known risk factors for the disease, the chronic cholera situation in Africa is due to the poor socioeconomic development status, weak household and community resilience, low literacy levels, weak capacity of African countries to implement the 2005 International Health Regulation and the pervasively weak health system on the continent. Stemming this tide requires good leadership, partnership, political commitment, and equity in access to health services, water, and sanitation. Therefore, we recommend that African governments and stakeholders recognize and approach cholera prevention and control from the long-term development lens and leverage the current cholera emergency preparedness and response efforts on the continent to strengthen the affected countries' health, water, and sanitation systems. We call on international organizations such as WHO and the Africa Centres for Diseases Control to support African governments in scaling up research and innovations aimed at better characterizing the epidemiology of cholera and developing evidence-based, context-specific, and innovative strategies for its prevention and control. These recommendations require long-term multisectoral and multidisciplinary approaches.