Cholera

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.

Global and regional final point-of-drinking water prevalence of Vibrio pathogens: a systematic analysis with socioeconomic, global health security, and WASH indices-guided meta-regressions

The final point-of-drinking water (FPODW) exposure to Vibrio and waterborne pathogens remains a misaim surveillance target. Therefore, the current study purposed to estimate the global and regional prevalence of Vibrio pathogens in FPODW. Vibrio-FPODW data derived from integrated databases per PRISMA protocol were fitted to a random-intercept-logistic mixed-effects and meta-regression models. The global FPODW Vibrio prevalence was 5.13% (95%CI: 2.24-11.30) with 7.76% (6.84-8.78) cross-validated value. Vibrio prevalence in different FPODW varied with the highest in unclassified (13.98%, 3.98-38.95), household stored (6.42%, 1.16-28.69), municipal (4.39%, 1.54-11.90), and bottled (1.06%, 0.00-98.57) FPODW. Regionally, FPODW Vibrio prevalence varied significantly with highest in Africa (6.31%, 0.49-47.88), then Asia (4.83%, 2.01-11.18). Similarly, it varied significantly among income classification with the highest from low-income (8.77%, 0.91-50.05), then lower-middle-income (6.16%, 2.75-13.20), upper-middle-income (0.23%, 0.00-82.04), and 0.94% (0.19-2.72) in high-income economies. Among the WHO region, it varied significantly from 1.41% (0.17-10.45) in Eastern Mediterranean, 6.31% (0.49-47.88) in Africa to 8.86% (3.85-19.06) in South-East Asia and declining among SDI-quintiles from 11.64% (3.29-33.83) in Low-SDI, 10.59% (4.58-22.61) in High-middle-SDI to 0.26% (0.01-9.09) in Middle-SDI. FPODW Vibrio prevalence was 7.31% (2.94-17.03) in the low-GHSIG, followed by 4.55% (0.00-100.00) in the upper-GHSIG, and 2.21% (0.31-14.24) in middle-GHSIG; rural (4.18%, 0.06-76.17) and urban (5.28%, 2.35-11.44) settings. Also, sample size, SDI, SDI-quintiles, and nation significantly explained 14.12%, 10.91%, 30.35%, and 87.65% variance in FPODW Vibrio prevalence, respectively as a univariate influence. Additionally, 11.90% variance in FPODW Vibrio prevalence explained mortality rate attributed to unsafe WASH services. In conclusion, the study revealed a substantial high FPODW prevalence of Vibrio calling for initiative-taking and intentional surveillances of waterborne pathogens at the neglected stage across nations in order to achieve sustainably the SDG 3.

Pathways of exposure to Vibrio Cholerae in an urban informal settlement in Nairobi, Kenya

Cholera is a diarrhoeal disease caused by Vibrio cholerae (V. cholerae) bacterium, with strains belonging to serogroups 01 and 0139 causing a huge proportion of the disease. V. cholerae can contaminate drinking water sources and food through poor sanitation and hygiene. This study aimed to identify environmental routes of exposure to V. cholerae within Mukuru informal settlement in Nairobi. We collected nine types of environmental samples (drinking water, flood water, open drains, surface water, shaved ice, raw produce, street food, soil, and public latrine swabs) over 12 months. All samples were analysed for V. cholerae by culture and qPCR, then qPCR-positive samples were quantified using a V. cholerae DNA standard. Data about the frequency of contact with the environment was collected using behavioural surveys. Of the 803 samples collected, 28.5% were positive for V. cholerae by qPCR. However, none were positive for V. cholerae by culture. V. cholerae genes were detected in majority of the environmental water samples (79.3%), including open drains, flood water, and surface water, but were only detected in small proportions of other sample types. Vibrio-positive environmental water samples had higher mean V. cholerae concentrations [2490-3469 genome copies (gc) per millilitre (mL)] compared to drinking water samples (25.6 gc/mL). Combined with the behavioural data, exposure assessment showed that contact with surface water had the highest contribution to the total V. cholerae exposure among children while ingestion of municipal drinking water and street food and contact with surface water made substantial contributions to the total V. cholerae exposure for adults. Detection of V. cholerae in street food and drinking water indicates possible risk of exposure to toxigenic V. cholerae in this community. Exposure to V. cholerae through multiple pathways highlights the need to improve water and sanitation infrastructure, strengthen food hygiene practices, and roll out cholera vaccination.

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.

Advances in phage display based nano immunosensors for cholera toxin

Cholera, a persistent global public health concern, continues to cause outbreaks in approximately 30 countries and territories this year. The imperative to safeguard water sources and food from Vibrio cholerae, the causative pathogen, remains urgent. The bacterium is mainly disseminated via ingestion of contaminated water or food. Despite the plate method's gold standard status for detection, its time-consuming nature, taking several days to provide results, remains a challenge. The emergence of novel virulence serotypes raises public health concerns, potentially compromising existing detection methods. Hence, exploiting Vibrio cholerae toxin testing holds promise due to its inherent stability. Immunobiosensors, leveraging antibody specificity and sensitivity, present formidable tools for detecting diverse small molecules, encompassing drugs, hormones, toxins, and environmental pollutants. This review explores cholera toxin detection, highlighting phage display-based nano immunosensors' potential. Engineered bacteriophages exhibit exceptional cholera toxin affinity, through specific antibody fragments or mimotopes, enabling precise quantification. This innovative approach promises to reshape cholera toxin detection, offering an alternative to animal-derived methods. Harnessing engineered bacteriophages aligns with ethical detection and emphasizes sensitivity and accuracy, a pivotal stride in the evolution of detection strategies. This review primarily introduces recent advancements in phage display-based nano immunosensors for cholera toxin, encompassing technical aspects, current challenges, and future prospects.

Cholera Infection Risks and Cholera Vaccine Safety in Pregnancy

Introduction

Discuss the impact of cholera infection on pregnant women, fetus, and neonates and review the safety of cholera vaccines in pregnancy.

Methods

This study was carried out as a narrative review during November 2022. A thorough literature review was conducted on the following databases: PubMed, Scopus, SciELO, CINAHL, Web of Science, and ScienceDirect. The following parameters were assessed from the included studies: type of cholera vaccine, cholera symptoms, cholera treatment, effect of cholera on pregnancy, effect of cholera treatment on pregnancy, effect of cholera vaccine on pregnancy, risk factors for fetuses and neonates, and prevention of cholera. The authors independently extracted data from the 24 included studies.

Results

Cholera infection is a serious threat on pregnancy as it could lead to increased stillbirths and neonatal death. Fetal death was shown to occur mainly in the third trimester as most of the pregnant women infected with cholera had spontaneous abortions even after controlling for other confounding variables such as maternal age, dehydration level, and vomiting. Neonatal death was attributed mainly to congenital malformations and low Apgar scores with no improvements. Besides, cholera vaccines have shown to be safe in pregnancy and have proven to lower fetal and neonatal malformations among vaccinated compared to nonvaccinated pregnant women.

Conclusion

This narrative summarizes the different complications due to cholera infection in pregnancy. It also reviews the safety of cholera vaccine administration in pregnant women.

Food as a Driver of a Cholera Epidemic in Jijiga, Ethiopia-June 2017

We conducted a case-control study to identify risk and protective factors during a cholera outbreak in Jijiga, Ethiopia, in June 2017. A case-patient was defined as anyone > 5 years old with at least three loose stools in 24 hours who was admitted to a cholera treatment center in Jijiga on or after June 16, 2017. Two controls were matched to each case by type of residency (rural or urban) and age group. We enrolled 55 case-patients and 102 controls from June 16 to June 23, 2017. Identified risk factors for cholera were male sex, eating cold food, and eating food outside the home. Eating hot food was protective, as was reported handwashing after defecation; no other reported water, sanitation, and hygiene factors were associated with cholera risk. Recommendations included continuing messaging about safe food handling practices at home, the dangers of consuming meals prepared away from home, and the importance of hand hygiene practices.

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

The resurgence of cholera is presenting unusual challenges in the Eastern Mediterranean Region (EMR), where it is considered endemic in nine-member states. The risk of a cholera outbreak spreading to non-endemic countries remains high. We discuss the regional trends of cholera, regional burden, and challenges with a focus on World Health Organization (WHO) initiatives in the region that could be useful in preventing and controlling the disease in similar contexts. Despite significant progress in the control of cholera worldwide, the disease continues to be a major public health problem across the region, where it constitutes both an emerging and re-emerging threat. Recurring cholera outbreaks are an indication of deprived water and sanitation conditions as well as weak health systems, contributing to the transmission and spread of the cholera infection. We note that despite the challenges in eliminating cholera in the region, effective implementation of the proposed WHO EMR Strategic framework, among other measures, could sustain the region's cholera prevention, preparedness, and response needs.

Examining challenges and multi-strategic approaches in waste management during the COVID-19 pandemic: A systematic review

The COVID-19 pandemic has a negative impact on the environment. Waste generation and improper management during the COVID-19 pandemic posed a major threat to human health and the environment. Irregular and improper waste collection, handling, suspension of waste recycling and unsanitary disposal were all important issues in the processing and management of generated waste. This study emphasised a systematic review and content analysis to categorise all types of waste management (WM) during the COVID-19 pandemic to accomplish a well understanding of the relation between the COVID-19 pandemic and its impacts on WM within the literature. In this systematic review, a number of published papers on different aspects of WM during March 2020 to February 2021 were considered in order to identify major challenges in handling WM during the pandemic time and highlight multi-strategic approaches suggested. A content analysis of the 58 relevant papers was carried out by incorporating different types of WM at local as well as global scales. The present review results revealed that the COVID-19 has impacted the quantity and composition of waste, and the crisis caused by the pandemic has also altered the nature of global WM system. A comprehensive analysis on how the systems of WM were affected through the advancement of COVID-19 and what would be the healthier solutions was also highlighted in this systematic review. The results of this systematic review would be beneficial for better policymakers to holistically address potential future pandemics, if any.

Risk Factors for Epidemic Cholera in Lusaka, Zambia-2017

On October 6, 2017, the Zambia Ministry of Health declared a cholera outbreak in Lusaka. By December, 1,462 cases and 38 deaths had occurred (case fatality rate, 2.6%). We conducted a case-control study to identify risk factors and inform interventions. A case was any person with acute watery diarrhea (≥ 3 loose stools in 24 hours) admitted to a cholera treatment center in Lusaka from December 16 to 21, 2017. Controls were neighbors without diarrhea during the same time period. Up to two controls were matched to each case by age-group (1-4, 5-17, and ≥ 18 years) and neighborhood. Surveyors interviewed cases and controls, tested free chlorine residual (FCR) in stored water, and observed the presence of soap in the home. Conditional logistic regression was used to generate matched odds ratios (mORs) based on subdistricts and age-groups with 95% CIs. We enrolled 82 cases and 132 controls. Stored water in 71% of case homes had an FCR > 0.2 mg/L. In multivariable analyses, those who drank borehole water (mOR = 2.4, CI: 1.1-5.6), had close contact with a cholera case (mOR = 6.2, CI: 2.5-15), and were male (mOR = 2.5, CI: 1.4-5.0) had higher odds of being a cholera case than their matched controls. Based on these findings, we recommended health education about household water chlorination and hygiene in the home. Emergency responses included providing chlorinated water through emergency tanks and maintaining adequate FCR levels through close monitoring of water sources.

Risk and Protective Factors for Cholera Deaths during an Urban Outbreak-Lusaka, Zambia, 2017-2018

The Republic of Zambia declared a cholera outbreak in Lusaka, the capital, on October 6, 2017. By mid-December, 20 of 661 reported cases had died (case fatality rate 3%), prompting the CDC and the Zambian Ministry of Health through the Zambia National Public Health Institute to investigate risk factors for cholera mortality. We conducted a study of cases (cholera deaths from October 2017 to January 2018) matched by age-group and onset date to controls (persons admitted to a cholera treatment center [CTC] and discharged alive). A questionnaire was administered to each survivor (or relative) and to a family member of each decedent. We used univariable exact conditional logistic regression to calculate matched odds ratios (mORs) and 95% CIs. In the analysis, 38 decedents and 76 survivors were included. Median ages for decedents and survivors were 38 (range: 0.5-95) and 25 (range: 1-82) years, respectively. Patients aged > 55 years and those who did not complete primary school had higher odds of being decedents (matched odds ratio [mOR] 6.3, 95% CI: 1.2-63.0, P = 0.03; mOR 8.6, 95% CI: 1.8-81.7, P < 0.01, respectively). Patients who received immediate oral rehydration solution (ORS) at the CTC had lower odds of dying than those who did not receive immediate ORS (mOR 0.1, 95% CI: 0.0-0.6, P = 0.02). Cholera prevention and outbreak response should include efforts focused on ensuring access to timely, appropriate care for older adults and less educated populations at home and in health facilities.