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Redae GA, Mengestu TK, Abdalla FM, Slim SN, Simon VT, Ali AO, Saguti GE, Habtu MM, Tegegne SG, Msambazi MJ, Zabulon Y. Towards cholera elimination in Zanzibar: analysis of evidences on what have worked. Pan Afr Med J 2023; 45:6. [PMID: 37538360 PMCID: PMC10395108 DOI: 10.11604/pamj.supp.2023.45.1.39828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/12/2023] [Indexed: 08/05/2023] Open
Abstract
Cholera, an enteric disease caused by Vibrio cholera claims thousands of lives yearly. The disease is a disease of inequality that affect populations which have poor access to safe water and sanitation facilities. Zanzibar, an archipelago in the Indian ocean which is part of the United Republic of Tanzania has been affected by recurrent cholera outbreak for the past decades. A multi-sectoral and multi-year three pillar approach namely Enabling Environment, Prevention and Response, for the elimination of cholera were initiated by the stewardship of the government, engagement of the community and technical and financial support of partners. The approach has enabled Zanzibar to interrupt the recurrent cholera outbreak for the past five years. The analysis of evidences have proven that creating an enabling environment through multi-sectoral involvement, mobilizing communities, intensifying surveillance complemented by the traditional disease prevention and control interventions has resulted to interruption of cholera transmission in the country.
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Affiliation(s)
| | | | | | | | | | - Ali Omar Ali
- World Health Organization Country Office, Dar es Salaam, Tanzania
| | | | | | | | | | - Yoti Zabulon
- World Health Organization Country Office, Dar es Salaam, Tanzania
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Montero DA, Vidal RM, Velasco J, George S, Lucero Y, Gómez LA, Carreño LJ, García-Betancourt R, O’Ryan M. Vibrio cholerae, classification, pathogenesis, immune response, and trends in vaccine development. Front Med (Lausanne) 2023; 10:1155751. [PMID: 37215733 PMCID: PMC10196187 DOI: 10.3389/fmed.2023.1155751] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/14/2023] [Indexed: 05/24/2023] Open
Abstract
Vibrio cholerae is the causative agent of cholera, a highly contagious diarrheal disease affecting millions worldwide each year. Cholera is a major public health problem, primarily in countries with poor sanitary conditions and regions affected by natural disasters, where access to safe drinking water is limited. In this narrative review, we aim to summarize the current understanding of the evolution of virulence and pathogenesis of V. cholerae as well as provide an overview of the immune response against this pathogen. We highlight that V. cholerae has a remarkable ability to adapt and evolve, which is a global concern because it increases the risk of cholera outbreaks and the spread of the disease to new regions, making its control even more challenging. Furthermore, we show that this pathogen expresses several virulence factors enabling it to efficiently colonize the human intestine and cause cholera. A cumulative body of work also shows that V. cholerae infection triggers an inflammatory response that influences the development of immune memory against cholera. Lastly, we reviewed the status of licensed cholera vaccines, those undergoing clinical evaluation, and recent progress in developing next-generation vaccines. This review offers a comprehensive view of V. cholerae and identifies knowledge gaps that must be addressed to develop more effective cholera vaccines.
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Affiliation(s)
- David A. Montero
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Roberto M. Vidal
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Instituto Milenio de Inmunología e Inmunoterapia, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Juliana Velasco
- Unidad de Paciente Crítico, Clínica Hospital del Profesor, Santiago, Chile
- Programa de Formación de Especialista en Medicina de Urgencia, Universidad Andrés Bello, Santiago, Chile
| | - Sergio George
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Yalda Lucero
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Departamento de Pediatría y Cirugía Infantil, Hospital Dr. Roberto del Rio, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Leonardo A. Gómez
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Leandro J. Carreño
- Instituto Milenio de Inmunología e Inmunoterapia, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Richard García-Betancourt
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Miguel O’Ryan
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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Ismail SA, Lam ST, Bell S, Fouad FM, Blanchet K, Borghi J. Strengthening vaccination delivery system resilience in the context of protracted humanitarian crisis: a realist-informed systematic review. BMC Health Serv Res 2022; 22:1277. [DOI: 10.1186/s12913-022-08653-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 10/09/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Childhood vaccination is among the most effective public health interventions available for the prevention of communicable disease, but coverage in many humanitarian settings is sub-optimal. This systematic review critically evaluated peer-review and grey literature evidence on the effectiveness of system-level interventions for improving vaccination coverage in protracted crises, focusing on how they work, and for whom, to better inform preparedness and response for future crises.
Methods
Realist-informed systematic review of peer-reviewed and grey literature. Keyword-structured searches were performed in MEDLINE, EMBASE and Global Health, CINAHL, the Cochrane Collaboration and WHOLIS, and grey literature searches performed through the websites of UNICEF, the Global Polio Eradication Initiative (GPEI) and Technical Network for Strengthening Immunization Services. Results were independently double-screened for inclusion on title and abstract, and full text. Data were extracted using a pre-developed template, capturing information on the operating contexts in which interventions were implemented, intervention mechanisms, and vaccination-related outcomes. Study quality was assessed using the MMAT tool. Findings were narratively synthesised.
Results
50 studies were included, most describing interventions applied in conflict or near-post conflict settings in sub-Saharan Africa, and complex humanitarian emergencies. Vaccination campaigns were the most commonly addressed adaptive mechanism (n = 17). Almost all campaigns operated using multi-modal approaches combining service delivery through multiple pathways (fixed and roving), health worker recruitment and training and community engagement to address both vaccination supply and demand. Creation of collaterals through service integration showed generally positive evidence of impact on routine vaccination uptake by bringing services closer to target populations and leveraging trust that had already been built with communities. Robust community engagement emerged as a key unifying mechanism for outcome improvement across almost all of the intervention classes, in building awareness and trust among crisis-affected populations. Some potentially transformative mechanisms for strengthening resilience in vaccination delivery were identified, but evidence for these remains limited.
Conclusion
A number of interventions to support adaptations to routine immunisation delivery in the face of protracted crisis are identifiable, as are key unifying mechanisms (multi-level community engagement) apparently irrespective of context, but evidence remains piecemeal. Adapting these approaches for local system resilience-building remains a key challenge.
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Ratnayake R, Peyraud N, Ciglenecki I, Gignoux E, Lightowler M, Azman AS, Gakima P, Ouamba JP, Sagara JA, Ndombe R, Mimbu N, Ascorra A, Welo PO, Mukamba Musenga E, Miwanda B, Boum Y, Checchi F, Edmunds WJ, Luquero F, Porten K, Finger F. Effectiveness of case-area targeted interventions including vaccination on the control of epidemic cholera: protocol for a prospective observational study. BMJ Open 2022; 12:e061206. [PMID: 35793924 PMCID: PMC9260795 DOI: 10.1136/bmjopen-2022-061206] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION Cholera outbreaks in fragile settings are prone to rapid expansion. Case-area targeted interventions (CATIs) have been proposed as a rapid and efficient response strategy to halt or substantially reduce the size of small outbreaks. CATI aims to deliver synergistic interventions (eg, water, sanitation, and hygiene interventions, vaccination, and antibiotic chemoprophylaxis) to households in a 100-250 m 'ring' around primary outbreak cases. METHODS AND ANALYSIS We report on a protocol for a prospective observational study of the effectiveness of CATI. Médecins Sans Frontières (MSF) plans to implement CATI in the Democratic Republic of the Congo (DRC), Cameroon, Niger and Zimbabwe. This study will run in parallel to each implementation. The primary outcome is the cumulative incidence of cholera in each CATI ring. CATI will be triggered immediately on notification of a case in a new area. As with most real-world interventions, there will be delays to response as the strategy is rolled out. We will compare the cumulative incidence among rings as a function of response delay, as a proxy for performance. Cross-sectional household surveys will measure population-based coverage. Cohort studies will measure effects on reducing incidence among household contacts and changes in antimicrobial resistance. ETHICS AND DISSEMINATION The ethics review boards of MSF and the London School of Hygiene and Tropical Medicine have approved a generic protocol. The DRC and Niger-specific versions have been approved by the respective national ethics review boards. Approvals are in process for Cameroon and Zimbabwe. The study findings will be disseminated to the networks of national cholera control actors and the Global Task Force for Cholera Control using meetings and policy briefs, to the scientific community using journal articles, and to communities via community meetings.
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Affiliation(s)
- Ruwan Ratnayake
- Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
- Epicentre, Paris, France
| | | | | | | | | | - Andrew S Azman
- Médecins Sans Frontières, Geneva, Switzerland
- Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | | | | | | | | | | | | | - Placide Okitayemba Welo
- Programme National d'Elimination du Choléra et de lutte contre les autres Maladies Diarrhéiques, Kinshasa, Congo (the Democratic Republic of the)
| | | | - Berthe Miwanda
- Institut National de Recherche Biologique, Kinshasa, Congo (the Democratic Republic of the)
| | | | - Francesco Checchi
- Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - W John Edmunds
- Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Francisco Luquero
- Epicentre, Paris, France
- GAVI the Vaccine Alliance, Geneva, Switzerland
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Haddison E, Tambasho A, Kouamen G, Ngwafor R. Vaccinators' Perception of HPV Vaccination in the Saa Health District of Cameroon. Front Public Health 2022; 9:748910. [PMID: 35083187 PMCID: PMC8784768 DOI: 10.3389/fpubh.2021.748910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 12/07/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: Cervical cancer is the second most prevalent cancer among women in Cameroon. In November 2020, the HPV vaccine was introduced into the expanded programme on immunisation. However, uptake of the vaccine has been slow in the Centre region as opposed to other regions in the country. We therefore sought to describe vaccinators' perception of HPV vaccination in Saa health district. Methods: A self-administered questionnaire with both open-ended and closed questions was used to assess the perception of HPV vaccination among 24 vaccinators from the Saa health district. Quantitative data were summarised as proportions while qualitative data were deductively and inductively coded and thematically analysed. Results: Most vaccinators (75%, n = 18) had a good knowledge about cervical cancer and HPV vaccination. Fourteen (58.3%, n = 14) vaccinators correctly reported the target group, number and spacing of doses for the HPV vaccine. Fourteen (58.3%) vaccinators favoured HPV vaccination while the others (n = 10) were sceptical. Sceptics felt manufacturers hadn't given enough proof of the safety of the vaccine and lacked confidence in government's assessment of the epidemiological situation. The COVID 19 pandemic, fear of infertility and the negative influence of social media were perceived as the main reasons for community hesitancy. Vaccinators criticised health authorities for failing to sensitise the population about the HPV vaccine before its introduction. Conclusion: Vaccinators' perceptions of HPV vaccination may influence the offer of HPV vaccination services. Measures to increase acceptance of HPV vaccination and ownership of the activity among vaccinators have to be put in place.
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Affiliation(s)
| | - Afizu Tambasho
- Central Technical Group-Expanded Programme on Immunisation, Ministry of Public Health, Yaounde, Cameroon
| | - Gael Kouamen
- Regional Delegation of Public Health, Bafoussam, Cameroon
| | - Randolph Ngwafor
- Biotechnology Centre, University of Yaounde 1, Yaounde, Cameroon
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