Socioecological systems analysis of potential factors for cholera outbreaks and assessment of health system's readiness to detect and respond in Ilemela and Nkasi districts, Tanzania.

BACKGROUND: Cholera outbreaks are a recurrent issue in Tanzania, with Ilemela and Nkasi districts being particulary affected. The objective of this study was to conduct a socio-ecological system (SES) analysis of cholera outbreaks in these districts, identifying potential factors and assessing the preparedness for cholera prevention and control. METHODS: A cross-sectional study was carried out in Ilemela and Nkasi districts of Mwanza and Rukwa regions, respectively in Tanzania between September and October 2021. A SES framework analysis was applied to identify potential factors associated with cholera outbreaks and assess the readiness of the districts to cholera prevention and control. RESULTS: Ilemela is characterised by urban and peri-urban ecosystems while Nkasi is mainly rural. Cholera was reported to disproportionately affect people living along the shores of Lake Victoria in Ilemela and Lake Tanganyika in Nkasi, particularly fishermen and women involved infish trading. The main potential factors identified for cholera outbreaks included defecation in the shallow ends and along the edges of lakes, open defecation, bathing/swimming in contaminated waters and improper waste disposal. The preparedness of both districts for cholera prevention and response was found to be inadequate due to limited laboratory capacity, insufficient human resources, and budget constraints. CONCLUSION: People of Ilemela and Nkasi districts remain at significant risk of recurrent cholera outbreaks and the capacity of the districts to detect the disease is limited. Urgent preventive measures, such as conducting considerable community awareness campaigns on personal hygiene and environmental sanitation are needed to alleviate the disease burden and reduce future cholera outbreaks.

Eastern Mediterranean Health Journal [2023; Vol.29, Issue 11]

Eastern Mediterranean Health Journal is the official health journal published by the Eastern Mediterranean Regional Office of the World Health Organization. It is a forum for the presentation and promotion of new policies and initiatives in health services; and for the exchange of ideas concepts epidemiological data research findings and other information with special reference to the Eastern Mediterranean Region. It addresses all members of the health profession medical and other health educational institutes interested NGOs WHO Collaborating Centres and individuals within and outside the Region

المجلة الصحية لشرق المتوسط هى المجلة الرسمية التى تصدرعن المكتب الاقليمى لشرق المتوسط بمنظمة الصحة العالمية. وهى منبر لتقديم السياسات والمبادرات الجديدة فى الصحة العامة والخدمات الصحية والترويج لها، و لتبادل الاراء و المفاهيم والمعطيات الوبائية ونتائج الابحاث وغير ذلك من المعلومات، و خاصة ما يتعلق منها باقليم شرق المتوسط. وهى موجهة الى كل اعضاء المهن الصحية، والكليات الطبية وسائر المعاهد التعليمية، و كذا المنظمات غير الحكومية المعنية، والمراكز المتعاونة مع منظمة الصحة العالمية والافراد المهتمين بالصحة فى الاقليم و خارجه

La Revue de Santé de la Méditerranée Orientale est une revue de santé officielle publiée par le Bureau régional de l’Organisation mondiale de la Santé pour la Méditerranée orientale. Elle offre une tribune pour la présentation et la promotion de nouvelles politiques et initiatives dans le domaine de la santé publique et des services de santé ainsi qu’à l’échange d’idées de concepts de données épidémiologiques de résultats de recherches et d’autres informations se rapportant plus particulièrement à la Région de la Méditerranée orientale. Elle s’adresse à tous les professionnels de la santé aux membres des instituts médicaux et autres instituts de formation médico-sanitaire aux ONG Centres collaborateurs de l’OMS et personnes concernés au sein et hors de la Région

Cholera past and future in Nigeria: Are the Global Task Force on Cholera Control's 2030 targets achievable?

BACKGROUND: Understanding and continually assessing the achievability of global health targets is key to reducing disease burden and mortality. The Global Task Force on Cholera Control (GTFCC) Roadmap aims to reduce cholera deaths by 90% and eliminate the disease in twenty countries by 2030. The Roadmap has three axes focusing on reporting, response and coordination. Here, we assess the achievability of the GTFCC targets in Nigeria and identify where the three axes could be strengthened to reach and exceed these goals. METHODOLOGY/PRINCIPAL FINDINGS: Using cholera surveillance data from Nigeria, cholera incidence was calculated and used to model time-varying reproduction number (R). A best fit random forest model was identified using R as the outcome variable and several environmental and social covariates were considered in the model, using random forest variable importance and correlation clustering. Future scenarios were created (based on varying degrees of socioeconomic development and emissions reductions) and used to project future cholera transmission, nationally and sub-nationally to 2070. The projections suggest that significant reductions in cholera cases could be achieved by 2030, particularly in the more developed southern states, but increases in cases remain a possibility. Meeting the 2030 target, nationally, currently looks unlikely and we propose a new 2050 target focusing on reducing regional inequities, while still advocating for cholera elimination being achieved as soon as possible. CONCLUSION/SIGNIFICANCE: The 2030 targets could potentially be reached by 2030 in some parts of Nigeria, but more effort is needed to reach these targets at a national level, particularly through access and incentives to cholera testing, sanitation expansion, poverty alleviation and urban planning. The results highlight the importance of and how modelling studies can be used to inform cholera policy and the potential for this to be applied in other contexts.

Assessment of the influence of ABO blood groups on oral cholera vaccine immunogenicity in a cholera endemic area in Zambia.

BACKGROUND: Histo-blood group antigens (HBGAs) which include the ABO and Lewis antigen systems have been known for determining predisposition to infections. For instance, blood group O individuals have a higher risk of severe illness due to V. cholerae compared to those with non-blood group O antigens. We set out to determine the influence that these HBGAs have on oral cholera vaccine immunogenicity and seroconversion in individuals residing within a cholera endemic area in Zambia. METHODOLOGY: We conducted a longitudinal study nested under a clinical trial in which samples from a cohort of 223 adults who were vaccinated with two doses of Shanchol™ and followed up over 4 years were used. We measured serum vibriocidal geometric mean titers (GMTs) at Baseline, Day 28, Months 6, 12, 24, 30, 36 and 48 in response to the vaccine. Saliva obtained at 1 year post vaccination was tested for HBGA phenotypes and secretor status using an enzyme-linked immunosorbent assay (ELISA). RESULTS: Of the 133/223 participants included in the final analysis, the majority were above 34 years old (58%) and of these, 90% were males. Seroconversion rates to V. cholerae O1 Inaba with non-O (23%) and O (30%) blood types were comparable. The same pattern was observed against O1 Ogawa serotype between non-O (25%) and O (35%). This trend continued over the four-year follow-up period. Similarly, no significant differences were observed in seroconversion rates between the non-secretors (26%) and secretors (36%) against V. cholerae O1 Inaba. The same was observed for O1 Ogawa in non-secretors (22%) and the secretors (36%). CONCLUSION: Our results do not support the idea that ABO blood grouping influence vaccine uptake and responses against cholera.

Pre-emptive oral cholera vaccine (OCV) mass vaccination campaign in Cuamba District, Niassa Province, Mozambique: feasibility, vaccination coverage and delivery costs using CholTool.

INTRODUCTION: Mozambique suffers from regular floods along its principal river basins and periodic cyclones that resulted in several cholera epidemics during the last decades. Cholera outbreaks in the recent 5 years affected particularly the northern provinces of the country including Nampula and Niassa provinces. A pre-emptive oral cholera vaccine (OCV) mass vaccination campaign was conducted in Cuamba District, Niassa Province, and the feasibility, costs, and vaccination coverage assessed. METHODS: WHO prequalified OCV (Euvichol-Plus), a killed whole-cell bivalent vaccine containing Vibrio cholerae O1 (classical and El Tor) and O139, was administered in two doses with a 15-day interval during 7-31 August 2018, targeting around 180 000 people aged above 1 year in Cuamba District. Microplanning, community sensitisation, and training of local public health professionals and field enumerators were conducted. Feasibility and costs of vaccination were assessed using CholTool. Vaccination coverage and barriers were assessed through community surveys. RESULTS: The administrative coverage of the first and second rounds of the campaign were 98.9% (194 581) and 98.8% (194 325), respectively, based on the available population data that estimated total 196 652 inhabitants in the target area. The vaccination coverage survey exhibited 75.9% (±2.2%) and 68.5% (±3.3%) coverage for the first and second rounds, respectively. Overall, 60.4% (±3.4%) of the target population received full two doses of OCV. Barriers to vaccination included incompatibility between working hours and campaign time. No severe adverse events were notified. The total financial cost per dose delivered was US$0.60 without vaccine cost and US$1.98 including vaccine costs. CONCLUSION: The pre-emptive OCV mass vaccination campaign in remote setting in Mozambique was feasible with reasonable full-dose vaccination coverage to confer sufficient herd immunity for at least the next 3 to 5 years. The delivery cost estimate indicates that the OCV campaign is affordable as it is comparable with Gavi's operational support for vaccination campaigns.

Conditions to eliminate cholera in Mozambique - the pathway for the development of the national cholera plan.

Cholera disproportionately affects the most vulnerable segments of the population, particularly those who have low or no access to basic water, sanitation, and hygiene (WASH). Despite some improvements in WASH conditions, cholera still represents a persistent challenge in Mozambique, where outbreaks occur almost every year, with high case fatality rates, posing a threat to the country's economic development. The Government of Mozambique has started developing a revised National Cholera Plan (NCP), which aligns with "ending cholera-a global roadmap to 2030" launched by the Global Task Force on Cholera Control (GTFCC) in 2017. Ending cholera represents a critical step towards achieving the sustainable development goals and requires effective prevention and control interventions, ensuring that no one is left behind. The NCP must use a multi-sector approach and broad stakeholder collaboration with well-coordinated roles and functions of different partners to address major areas for cholera elimination - water and sanitation, health care services and management, epidemiology and surveillance, and health and hygiene promotion. Every cholera death is preventable. In this review, we reiterate the need for effective coordinated actions to control and eliminate cholera in Mozambique and decrease the cholera burden, enabling a healthy population over the generations.

An Assessment of Household Knowledge and Practices during a Cholera Epidemic- Dar es Salaam, Tanzania, 2016.

From August 15, 2015 to March 5, 2016, Tanzania reported 16,521 cholera cases and 251 deaths, with 4,596 cases and 44 deaths in its largest city, Dar es Salaam. To evaluate outbreak response efforts, we conducted a household survey with drinking water testing in the five most affected wards in Dar es Salaam. We interviewed 641 households 6 months after the beginning of the outbreak. Although most respondents knew that cholera causes diarrhea (90%) and would seek care if suspecting cholera (95%), only 45% were aware of the current outbreak in the area and only 5% would use oral rehydration salts (ORS) if ill. Of 200 (31%) respondents reporting no regular water treatment, 46% believed treatment was unnecessary and 18% believed treatment was too expensive. Fecal contamination was found in 45% of water samples and was associated with water availability (P = 0.047). Only 11% of samples had detectable free chlorine residual, which was associated with water availability (P = 0.025), reported current water treatment (P = 0.006), and observed free chlorine product in the household (P = 0.015). The provision of accessible, adequately chlorinated water supply, and implementation of social mobilization campaigns advocating household water treatment and use of ORS should be prioritized to address gaps in cholera prevention and treatment activities.

Economic impact of cholera in households in rural southern Malawi: a prospective study.

INTRODUCTION: Cholera remains a significant contributor to diarrhoeal illness, especially in sub-Saharan Africa. Few studies have estimated the cost of illness (COI) of cholera in Malawi, a cholera-endemic country. The present study estimated the COI of cholera in Nsanje, southern Malawi, as part of the Cholera Surveillance in Malawi (CSIMA) programme following a mass cholera vaccination campaign in 2015. METHODS: Patients ≥12 months of age who were recruited as part of CSIMA were invited to participate in the COI survey. The COI tool captured household components of economic burden, including direct medical and non-medical costs, and indirect lost productivity costs. RESULTS: Between April 2016 and March 2020, 40 cholera cases were enrolled in the study, all of whom participated in the COI survey. Only two patients had any direct medical costs and five patients reported lost wages due to illness. The COI per patient was US$14.34 (in 2020), more than half of which was from direct non-medical costs from food, water, and transportation to the health centre. CONCLUSION: For the majority of Malawians who struggle to subsist on less than US$2 a day, the COI of cholera represents a significant cost burden to families. While cholera treatment is provided for free in government-run health centres, additional investments in cholera control and prevention at the community level and financial support beyond direct medical costs may be necessary to alleviate the economic burden of cholera on households in southern Malawi.

Cholera Outbreaks in India, 2011-2020: A Systematic Review.

Fecal contamination of water sources and open defecation have been linked to cholera outbreaks in India. However, a systematic review on the drivers responsible for these outbreaks has yet to be published. Here, we systematically review the published literature on cholera outbreaks in India between 2011 and 2020. We searched studies in English in three databases (MEDLINE, EMBASE, and Web of Science) and the Integrated Disease Surveillance Program that tracks cholera outbreaks throughout India. Two authors independently extracted data and assessed the quality of the included studies. Quantitative data on the modes of transmission reviewed in this study were assessed for any change over time between 2011-2015 and 2016-2020. Our search retrieved 10823 records initially, out of which 81 full-text studies were assessed for eligibility. Among these 81 studies, 20 were eligible for inclusion in this review. There were 565 reported outbreaks between 2011 and 2020 that led to 45,759 cases and 263 deaths. Outbreaks occurred throughout the year; however, they exploded with monsoons (June through September). In Tamil Nadu, a typical peak of cholera outbreaks was observed from December to January. Seventy-two percent (33,089/45,759) of outbreak-related cases were reported in five states, namely Maharashtra, West Bengal, Punjab, Karnataka, and Madhya Pradesh. Analysis of these outbreaks highlighted the main drivers of cholera including contaminated drinking water and food, inadequate sanitation and hygiene (including open defecation), and direct contact between households. The comparison between 2011-2015 and 2016-2020 showed a decreasing trend in the outbreaks that arose due to damaged water pipelines. Many Indians still struggle with open defecation, sanitation, and clean water access. These issues should be addressed critically. In addition, it is essential to interrupt cholera short-cycle transmission (mediated by households, stored drinking water and foodstuffs) during an outbreak. As cholera is associated with deprivation, socio-economic development is the only long-term solution.

Spanish Flu in Tehran from 1918 to 1920.

The Spanish flu spread from September 23, 1918 to 1920. This disease was one of the historical catastrophes in Iran, and a large number of people in Tehran were infected. Evidence also shows that 5000-10000 out of the 250000 infected people died in Tehran over three years. Besides, an increase was detected in the prevalence of other diseases such as pericarditis, orchitis, mastoiditis, meningitis, optic neuritis, paralysis of the palate, mania, cholera, and dysentery. Overall, five percent of the city were destroyed, and the population and economic development were severely damaged. This study aims to evaluate the importance of the history of local medicine in Tehran, the spread of Spanish flu, World War I, and presence of Russian, Ottoman, and British troops in Iran during the flu outbreak. The critical role of Britain in artificial famine, malnutrition, and drug embargo was assessed, as well.

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

BACKGROUND: Temperature 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. METHODS: Here, 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. RESULTS: The 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. CONCLUSIONS: Despite 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.

[Assessment of the humanitarian response to cholera in wash interventions.] / Evaluación de la respuesta humanitaria al cólera en las intervenciones WASH.

BACKGROUND: The humanitarian response to a cholera outbreak in a complex international crisis requires guaranteeing minimum conditions so that normalcy can be restored. Basic responses to a cholera outbreak include water and sanitation. The general objective of this systematic review was the analysis of the current evidence that addresses the effectiveness of different WASH measures to control cholera. METHODS: A review and analysis of the literature available in the main databases (PubMed, WoS and Scopus) and in a specific meta-search engine for humanitarian aid was carried out (reliefweb.int). Based on the establishment of the PICO research question "Can beneficiaries of humanitarian aid benefit from water, hygiene and sanitation interventions for cholera reduction?", the identification of keywords and databases to carry out the searches, as well as a selection process based on the established eligibility criteria: being studies in both English and Spanish where the WASH intervention was clearly defined, studies where health outcomes of cholera were presented, or data related to the function and use of the WASH intervention, was established. RESULTS: The initial search provided 17,185 documents susceptible of analysis that were screened using the search criteria, up to 22 references that were read in full text and the 11 that were finally analyzed. These were coded based on the measures set out in their protocols, on the interventions carried out in the improvement of water and its supply, the improvement of sanitation, the measures aimed at better hygiene and those that evaluated the complete WASH intervention. CONCLUSIONS: All the measures offered positive results, their effectiveness was conditioned by the education of the beneficiaries, the simplicity of the activities and the involvement of local actors.

OBJETIVO: La respuesta humanitaria ante un brote de cólera en una crisis compleja de carácter internacional requiere garantizar unas condiciones mínimas para que se pueda recuperar la normalidad. Entre las respuestas básicas a un brote de cólera están las correspondientes al agua y el saneamiento. El objetivo general de esta revisión narrativa fue el análisis de la evidencia actual que aborda la efectividad de las diferentes medidas WASH para controlar el cólera. METODOS: Se realizó una revisión y análisis de la literatura disponible en las bases de datos principales (PubMed, WoS y Scopus) y en un metabuscador específico de ayuda humanitaria (reliefweb.int). Basada en el establecimiento de la pregunta de investigación PICO: "¿Los beneficiarios de la ayuda humanitaria se pueden beneficiar de las intervenciones en agua, higiene y saneamiento para la disminución del cólera?" la identificación de las palabras clave y bases de datos para realizar las búsquedas, además de un proceso de selección basado en los criterios de elegibilidad establecidos; siendo estudios tanto en inglés como español donde la intervención WASH fue claramente definida, estudios donde se presentaran resultados de salud del cólera, o datos relacionados con la función y el uso de la intervención WASH. RESULTADOS: La búsqueda inicial proporcionó 17.185 documentos susceptibles de análisis que fueron cribados mediante los criterios de búsqueda hasta las 22 referencias que fueron leídas a texto completo y las 11 que fueron analizadas finalmente. Estas fueron codificadas en base a las medidas expuestas en sus protocolos, a las intervenciones realizadas en la mejora del agua y su suministro, la mejora del saneamiento, las medidas destinadas a una mejor higiene y aquellas que evaluaban la intervención WASH completa. CONCLUSIONES: Todas las medidas ofrecieron resultados positivos, su eficacia estuvo condicionada por la educación de los beneficiarios, la simplicidad de las actividades y la implicación de los actores locales.

Intervention to Improve Diarrhea-Related Knowledge and Practices Among Informal Healthcare Providers in Slums of Kolkata.

BACKGROUND: In the densely populated slums of Kolkata, informal healthcare providers' (IHP) diarrhea-related knowledge and rationality of practices should be improved to reduce risk of adverse outcome, expenditure, and antimicrobial resistance. METHODS: A multicomponent intervention was conducted among 140 representative IHPs in the slums of 8 wards in Kolkata to assess its impact on their diarrhea-related knowledge and practice. Six intervention modules in local languages were provided (1 per month) with baseline (N = 140) and postintervention (N = 124) evaluation. RESULTS: Mean overall (61.1 to 69.3; P < .0001) and domain-specific knowledge scores for etiology/spread (5.4 to 8.1; P < .0001), management (6.4 to 7.2; P < .0001), and oral rehydration solution ([ORS] 5.7 to 6.5; P < .0001) increased significantly (at α = 0.05) after intervention and were well retained. Impact on knowledge regarding etiology/spread (adjusted odds ratio [aOR] = 5.6; P < .0001), cholera (aOR = 2.0; P = .0041), management (aOR = 3.1; P < .0001), ORS (aOR = 2.3; P = .0008), and overall (aOR = 4.3; P < .0001) were significant. Intervention worked better for IHPs who practiced for ≥10 years (aOR = 3.2; P < .0001), untrained IHPs (aOR = 4.8; P < .0001), and pharmacists (aOR = 8.3; P < .0001). Irrational practices like empirical antibiotic use for every cholera case (aOR = 0.3; P < .0001) and investigation for every diarrhea case (aOR = 0.4; P = .0003) were reduced. Rationality of testing (aOR = 4.2; P < .0001) and antibiotic use (aOR = 1.8; P = .0487) improved. CONCLUSIONS: Multicomponent educational intervention resulted in sustainable improvement in diarrhea-related knowledge and practices among IHPs in slums of Kolkata. Policy implications should be advocated along with implementation and scale-up.