Prevalence and antimicrobial susceptibility pattern of Vibrio cholerae isolates from cholera outbreak sites in Ethiopia.

BACKGROUND: Cholera is an acute infectious disease caused by ingestion of contaminated food or water with Vibrio cholerae. Cholera remains a global threat to public health and an indicator of inequity and lack of social development. The aim of this study was to assess the prevalence and antimicrobial susceptibility pattern of V. cholerae from cholera outbreak sites in Ethiopia. METHODS: Across-sectional study was conducted from May 2022 to October 2023 across different regions in Ethiopia: Oromia National Regional State, Amhara National Regional State and Addis Ababa City Administration. A total of 415 fecal samples were collected from the three regions. Two milliliter fecal samples were collected from each study participants. The collected samples were cultured on Blood Agar, MacConkey Agar and Thiosulfate Citrate Bile Salt Sucrose Agar. A series of biochemical tests Oxidase test, String test, Motility, Indole, Citrate, Gas production, H2S production, Urease test were used to identify V. cholerae species. Both polyvalent and monovalent antisera were used for agglutination tests to identify and differentiate V. cholerae serogroup and serotypes. In addition, Kirby-Bauer Disk diffusion antibiotic susceptibility test method was done. Data were registered in epi-enfo version 7 and analyzed by Statistical Package for Social Science version 25. Descriptive statistics were used to determine the prevalence of Vibrio cholerae. Logistic regression model was fitted and p-value < 0.05 was considered as statically significant. RESULTS: The prevalence of V. cholerae in the fecal samples was 30.1%. Majority of the isolates were from Oromia National Regional State 43.2% (n = 54) followed by Amhara National Regional State 31.2% (n = 39) and Addis Ababa City Administration 25.6% (n = 32). Most of the V. cholerae isolates were O1 serogroups 90.4% (n = 113) and Ogawa serotypes 86.4% (n = 108). Majority of the isolates were susceptible to ciprofloxacin 100% (n = 125), tetracycline 72% (n = 90) and gentamycin 68% (n = 85). More than half of the isolates were resistant to trimethoprim-sulfamethoxazole 62.4% (n = 78) and ampicillin 56.8% (n = 71). In this study, participants unable to read and write were about four times more at risk for V. cholerae infection (AOR: 3.8, 95% CI: 1.07-13.33). In addition, consumption of river water were about three times more at risk for V. cholerae infection (AOR: 2.8, 95% CI: 1.08-7.08). CONCLUSION: our study revealed a high prevalence of V. cholerae from fecal samples. The predominant serogroups and serotypes were O1 and Ogawa, respectively. Fortunately, the isolates showed susceptible to most tested antibiotics. Drinking water from river were the identified associated risk factor for V. cholerae infection. Protecting the community from drinking of river water and provision of safe and treated water could reduce cholera outbreaks in the study areas.

Model-Based Estimation of Expected Time to Cholera Extinction in Lusaka, Zambia.

The developing world has been facing a significant health issue due to cholera as an endemic communicable disease. Lusaka was Zambia's worst affected province, with 5414 reported cases of cholera during the outbreak from late October 2017 to May 12, 2018. To explore the epidemiological characteristics associated with the outbreak, we fitted weekly reported cholera cases with a compartmental disease model that incorporates two transmission routes, namely environment-to-human and human-to-human. Estimates of the basic reproduction number show that both transmission modes contributed almost equally during the first wave. In contrast, the environment-to-human transmission appears to be mostly dominating factor for the second wave. Our study finds that a massive abundance of environmental vibrio's with a huge reduction in water sanitation efficacy triggered the secondary wave. To estimate the expected time to extinction (ETE) of cholera, we formulate the stochastic version of our model and find that cholera can last up to 6.5-7 years in Lusaka if any further outbreak occurs at a later time. Results indicate that a considerable amount of attention is to be paid to sanitation and vaccination programs in order to reduce the severity of the disease and to eradicate cholera from the community in Lusaka.

A cholera outbreak in a rural north central Nigerian community: an unmatched case-control study.

BACKGROUND: Cholera remains a disease of public health importance in Nigeria associated with high morbidity and mortality. In November 2014, the Nigeria Field Epidemiology and Laboratory Training Programme (NFELTP) was notified of an increase in suspected cholera cases in Gomani, Kwali Local Government Area. NFELTP residents were deployed to investigate the outbreak with the objectives of verifying the diagnosis, identifying risk factors and instituting appropriate control measures to control the outbreak. METHODS: We conducted an unmatched case-control study. We defined a cholera case as any person aged ≥5 years with acute watery diarrhea in Gomani community. We identified community controls. A total of 43 cases and 68 controls were recruited. Structured questionnaires were administered to both cases and controls. Four stool samples from case-patients and two water samples from the community water source were collected for laboratory investigation. We performed univariate and bivariate analysis using Epi-Info version 7.1.3.10. RESULTS: The mean age of cases and controls was 20.3 years and 25.4 respectively (p value 0.09). Females constituted 58.1% (cases) and 51.5%(controls). The attack rate was 4.3% with a case fatality rate of 13%. Four stool (100%) specimen tested positive for Vibrio cholerae. The water source and environment were polluted by indiscriminate defecation. Compared to controls, cases were more likely to have drank from Zamani river (OR 14.2, 95% CI: 5.5-36.8) and living in households(HH) with more than 5 persons/HH (OR 5.9, 95% CI: 1.3-27.2). Good hand hygiene was found to be protective (OR 0.3, 95% CI: 0.1-0.7). CONCLUSION: Vibrio cholerae was the cause of the outbreak in Gomani. Drinking water from Zamani river, living in overcrowded HH and poor hand hygiene were significantly associated with the outbreak. We initiated hand hygiene and water treatment to control the outbreak.

Modeling the 2016-2017 Yemen cholera outbreak with the impact of limited medical resources.

We present a mathematical model to investigate the transmission dynamics of the 2016-2017 Yemen cholera outbreak. Our model describes the interaction between the human hosts and the pathogenic bacteria, under the impact of limited medical resources. We fit our model to Yemen epidemic data published by the World Health Organization, at both the country and regional levels. We find that the Yemen cholera outbreak is shaped by the interplay of environmental, socioeconomic, and climatic factors. Our results suggest that improvement of the public health system and strategic implementation of control measures with respect to time and location are key to future cholera prevention and intervention in Yemen.

Cholera outbreak in South Africa, 2008-2009: laboratory analysis of Vibrio cholerae O1 strains.

BACKGROUND: A total of 720 Vibrio cholerae O1 strains were recovered for investigation from an outbreak of cholera in South Africa between November 2008 and April 2009. METHODS: Strains were characterized by serotype testing. Antimicrobial susceptibility testing. Genetic diversity of 248 strains was investigated using pulsed-field gel electrophoresis (PFGE) analysis. Extended characterization was performed on 90 strains. Molecular analysis included: polymerase chain reaction (PCR) identification of ctxA and tcpA genes, sequencing the ctxAB gene, and investigation of molecular mechanisms conferring antimicrobial resistance. RESULTS: The majority of strains were characterized as serotype Ogawa. Strains showed multidrug resistance. Approximately 1.0% of strains displayed extended-spectrum ß-lactamase (ESBL) activity. Strains showed very similar PFGE patterns. Ninety strains selected for extended characterization showed the following results: Strains possessed the cholera toxin (CT) and all were PCR positive for the tcpA-El Tor variant. Sequencing of the ctxB gene matched the B-1 allele. Strains harbored the SXT element. Strains that displayed ESBL activity possessed a 140-kilobase-pair plasmid that produced the TEM-63 ß-lactamase. Nalidixic acid-resistant strains harbored mutations in GyrA (Ser83-Ile) and ParC (Ser85-Leu). CONCLUSIONS: These data highlight the rapid development of antimicrobial resistance and spread of V. cholerae O1 El Tor variants expressing the classical CT within South Africa.

Existence of cholera outbreak, challenges, and way forward on public health interventions to control cholera outbreak in Guraghe Zones, southern Ethiopia, 2023.

Introduction: In Ethiopia, despite major improvements seen in health service delivery system, the country continues to be significantly affected by cholera outbreaks. Cholera remains a significant public health problem among the vulnerable populations living in many resource-limited settings with poor access to safe and clean water and hygiene practices. 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. Objective: To assess the cholera outbreak, its challenges, and the way forward on public health interventions to solve the knowledge and health service delivery gaps related to cholera control in Guraghe Zone, Ethiopia, 2023. Methods: Active surveillance of the cholera outbreak was conducted in all kebeles and town administrative of Guraghe zone from 7/8/2023 to 30/10/2023. A total of 224 cholera cases were detected during the active surveillance method. Data obtained from Guraghe zone offices were exported to SPSS version 25 for additional analysis. The case fatality rate, incidence of the cases, and other descriptive variables were presented and described using figures and tables. Result: A total of 224 cholera cases were detected through an active surveillance system. In this study, the case fatality rate of cholera outbreak was 2.6%. To tackle the cholera outbreak, the Guraghe zone health office collaborated with other stakeholders to prepare four cholera treatment centers. The absence of OCV, inaccessible safe water, low latrine coverage, inappropriate utilization of latrines, and absence of cholera laboratory rapid diagnostics test in Guraghe Zone are barriers to tackling the outbreak. Conclusion: Ethiopia National Cholera Plan targeted eradicating cholera by 2030, 222 cholera outbreak occurred in Guraghe Zone, Ethiopia. To minimize and control cholera mortality rate oral cholera vaccinations should be employed in all areas of the region. Sustainable WASH measures should be guaranteed for the use of safe water and good hygiene practices. Early diagnosis and treatment should be initiated appropriately for those who are infected.

A retrospective study on cholera understanding and WASH (water, sanitation, and hygiene) behavior among adolescents in three regions of La Gonâve, Haiti.

BACKGROUNDS: This study assesses the impact of Water, Sanitation, and Hygiene (WASH) interventions on cholera understanding and hygiene practices in La Gonâve Island, Haiti. It examines the changes after implementing interventions in seven villages across the Downtown, Mountain, and Seaside regions. METHODS: A retrospective investigation surveyed 210 school students from each region using a validated questionnaire. It assessed knowledge, attitudes, practices (KAP), and environmental aspects related to cholera and hygiene. Data analysis involved descriptive statistics and chi-square tests. RESULTS: The study highlights significant disparities in education levels, toilet ownership, and healthcare access. Challenges in finding public toilets (86.67%) and accessing water sources (67.78%) are consistent across regions, with Seaside facing financial constraints (85.00%) and water cost concerns (91.67%). Attitudes toward hygiene vary, with the Mountain region having the highest 'Never' responses for handwashing (38.89%), and Downtown leading in water treatment practices (11.67%). There is a strong willingness to share health knowledge, particularly in Downtown (100.00%). Seaside (83.33%) and Downtown (73.33%) revealed a higher cholera awareness, while nearly half of Mountain students lacked knowledge (54.44%). CONCLUSIONS: This study highlights significant disparities in WASH practices among La Gonâve's adolescents in Downtown, Mountain, and Seaside regions. Urgent interventions are crucial for improving sanitation, ensuring clean water access, and implementing targeted hygiene education, especially in the resource-constrained Mountain and Seaside areas. The findings underscore the vital roles of adolescents and schools in disseminating knowledge, with further research needed to explore intervention differences.

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.

Dr. Dilip Mahalanabis (1934-2022): Trailblazer in Diarrheal Disease Management.

Dilip Mahalanabis, an esteemed Indian pediatrician, revolutionized global health through his pioneering work in combatting diarrheal diseases, particularly during the Bangladesh War of Independence in 1971. His development of oral rehydration therapy (ORT) provided a simple, cost-effective solution that significantly reduced mortality rates among cholera patients. Mahalanabis' dedication to equitable healthcare, evidenced by his leadership roles in organizations such as the World Health Organization (WHO), underscores his legacy as a champion for vulnerable populations. ORT's widespread adoption has democratized treatment, empowering communities and drastically reducing mortality rates associated with diarrheal diseases.

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.

Sequential outbreaks due to mixed ctxB alleles of Vibrio cholerae O1 in Mayurbhanj district of Odisha, India.

INTRODUCTION: Cholera is a significant threat causing outbreaks/epidemics with high morbidity and mortality in coastal and tribal districts of Odisha. A sequential cholera outbreak reported from four places in Mayurbhanj district of Odisha during June to July 2009 was investigated. METHODOLOGY: Rectal swabs from diarrhea patients were analyzed for the identification, antibiogram profiles and detection of ctxB genotypes by double mismatch amplification mutation (DMAMA) polymerase chain reaction (PCR) assays and sequenced. The different virulent and drug resistant genes were detected by multiplex PCR assays. The clonality analysis on selected strains was done by pulse field gel electrophoresis (PFGE). RESULTS: Bacteriological analysis of rectal swabs revealed the presence of V. cholerae O1 Ogawa biotype El Tor which were resistant to co-trimoxazole, chloramphenicol, streptomycin, ampicillin, nalidixic acid, erythromycin, furazolidone and polymyxin B. DMAMA-PCR assay revealed that the cholera outbreak in Mayurbhanj district was due to both ctxB1 and ctxB7 alleles of V. cholerae O1 El Tor strains. All the V. cholerae O1 strains were positive for all virulence genes. The multiplex PCR assay on V. cholerae O1 strains revealed the presence of antibiotic resistance genes like dfrA1 (100%), intSXT (100%), sulII (62.5%) and StrB (62.5%). PFGE results on V. cholerae O1 strains exhibited two different pulsotypes with 92% similarity. CONCLUSIONS: This outbreak was a transition phase where both ctxB genotypes were prevalent after which the ctxB7 genotype gradually became dominant in Odisha. Therefore, close monitoring and continuous surveillance on diarrheal disorders is essential to prevent the future diarrheal outbreaks in this region.

Draft genomes of Aeromonas caviae from patients with cholera-like illness during the 2022-2023 cholera outbreak in Malawi.

Aeromonas caviae is an increasingly recognized etiological agent of acute gastroenteritis. Here, we report five draft genomes of A. caviae isolated from suspected cholera cases during the 2022-2023 cholera outbreak in Malawi.

Association between cholera treatment outcome and nutritional status in children aged 2-4 years in Nigeria.

SETTING: Cholera can aggravate or precipitate malnutrition, and children with severe acute malnutrition (SAM) have a higher incidence and longer duration of diarrhoea. OBJECTIVE: To describe 1) characteristics of and treatment outcomes in children aged 2-4 years with cholera, 2) the case fatality rate (CFR) in all children treated, and 3) the associations between nutritional status, hydration status, treatment administered and hospital outcomes. DESIGN: An observational cohort study of children admitted to one cholera treatment centre in Maiduguri, Nigeria, with a focus on children aged 2-4 years. CFRs were examined by cross tabulation and mean length of stay (LOS) using analysis of variance. RESULTS: SAM was identified in 24% of children aged 2-4 years. The CFR for children aged 2-4 years was 1.4%. As the sample size was small, we did not find any association between nutritional status and death due to cholera. The proportion of children discharged within 2 days was 79%, and the longest stay was 8 days. In general, health facility LOS increased with severity of malnutrition. CONCLUSION: Our study found that nutritional status affected the LOS, but was unable to find an association between malnutrition and fatality among children aged 2-4 years.

CONTEXTE: Le choléra peut aggraver ou précipiter la malnutrition et les enfants atteints de malnutrition aiguë grave (SAM) ont une incidence plus élevée et une durée plus longue de diarrhée. OBJECTIF: Décrire 1) les caractéristiques et les résultats du traitement d'enfants de 2­4 ans atteints de choléra, 2) le taux de mortalité de tous les enfants traités, et 3) les associations entre état nutritionnel, hydratation, traitement administré et évolution à l'hôpital. SCHÉMA: Cohorte d'observation d'enfants admis au centre de traitement du choléra de Maiduguri, Nigeria, avec un focus sur les enfants de 2­4 ans. Les taux de létalité ont été examinés par tabulation croisée et la durée moyenne de séjour par analyse de la variance. RÉSULTATS: Une SAM a été identifiée chez 24% des enfants de 2­4 ans. Le taux de létalité des enfants de 2­4 ans était de 1,4%. La petite taille de la population n'a pas permis d'observer d'association entre état nutritionnel et décès dû au choléra. La proportion d'enfants sortis en 48h a été de 79% et la durée la plus longue de séjour de 8 jours. En général, la durée de séjour en structure de santé augmentait avec la gravité de la malnutrition. CONCLUSION: Notre étude a constaté que l'état nutritionnel affectait la durée de séjour mais n'a pas permis de trouver une association entre malnutrition et létalité parmi les enfants de 2­4 ans.

A reactive vaccination campaign with single dose oral cholera vaccine (OCV) during a cholera outbreak in Cameroon.

BACKGROUND: Cameroon chose Oral Cholera Vaccine (OCV) mass vaccination campaign in addition to other interventions to respond to outbreaks since 2015. There is still a persistent controversy on the effectiveness of reactive OCV mass vaccination campaign. OBJECTIVE: This article aimed to share evidence-based observations on the effect of a reactive single-dose OCV mass vaccination campaign on cholera cases in Cameroon. METHODS: Health area centered risk analysis was used to identify nine high risk health areas among four health districts in the |North Region as hotspots. About 537,274 people at risk of cholera transmission one year of age and above including pregnant women were eligible to receive OCV. A total of 537,279 doses of OCV was deployed for vaccination from August 1-5, 2019 through door-to-door strategy for urban health districts, and fixed/ temporary fixed posts strategies for rural health districts. RESULTS: The overall vaccination coverage was 99.9%. Vaccine wastage rate was less than 0.5% (0.0011%). Independent monitoring showed vaccination coverage at 97.2%. The 2019 epidemic curve went down after OCV intervention on the contrary to that in the year 2018 at the same period. After OCV intervention, cholera cases dropped from about 10.5 to 9.3 cases per week at the regional level while at the district level, they dropped from 5.3 to 2.1, 2.2 to 1.7, 0.6 to 0 and 1.7 to 1.5 cases per week respectively for Garoua, Garoua II, Tchollire and Pitoa. Though not statistically significant (p = 1.4, α = 0.05), cases per 1000 population seemed to remain unchanged among OCV zones (0.32/1000) and non-OCV zones (0.31/1000) in 2018 while they increased from 0.37 (OCV zones) to 0.53 (non-0CV zones) cases per 1000 population in 2019. CONCLUSION: There might have been a general trend in the reduction of the number of new cases after a reactive single-dose OCV campaign.

Inland cholera in freshwater environs of north India.

In the freshwater environment of north India, cholera appears seasonally in form of clusters as well as sporadically, accounting for a significant piece of the puzzle of cholera epidemiology. We describe a number of cholera outbreaks with an average attack rate of 96.5/1000 but an overall low case fatality (0.17). Clinical cholera cases coincided with high rainfall and elevated temperatures, whereas isolation of V. cholerae non-O1 non-O139 from water was dependent on temperature (p < 0.05) but was independent of rainfall and pH (p > 0.05). However, isolation from plankton samples correlated with increased temperature and pH (p < 0.05). A lag period of almost a month was observed between rising temperature and increased isolation of V. cholerae from the environment, which in succession was followed by an appearance of cholera cases in the community a month later. Our results suggested that the aquatic environment can harbor highly divergent V. cholerae strains and serve as a reservoir for multiple V. cholera virulence-associated genes that may be exchanged via mobile genetic elements. In agreement with PFGE, AFLP data also proved that the V. cholerae O1 population was not clonal but was closely related. Our investigation did not support the concept that seasonal cholera outbreaks occur by movement of a single clonal strain across the region, as the clinical isolates from the same years were clearly different, implying that continuous evolution of V. cholerae O1 strains occurs in the cholera endemic area. Interestingly, the viable but non-culturable (VBNC) V. cholerae O1 cells were demonstrated in 2.21% samples from natural water bodies in addition to 40.69% samples from cholera-affected areas respectively. This suggests that aquatic environs do harbor the pathogenic O1 strain, though the isolation of culturable V. cholerae O1 is a rare event in the presence of relatively abundant non-O1 non-O139 isolates.

Outcomes of cholera and measles outbreak alerts in the Democratic Republic of Congo.

SETTING: In 1995, a rapid response project for humanitarian and medical emergencies, including outbreak responses, named 'Pool d'Urgence Congo' (PUC), was implemented in the Democratic Republic of Congo by Médecins Sans Frontières. OBJECTIVE: To assess the outcomes of cholera and measles outbreak alerts that were received in the PUC surveillance system between 2016 and 2018. DESIGN: This was a retrospective cross-sectional study. RESULTS: Overall, 459 outbreak alerts were detected, respectively 69% and 31% for cholera and measles. Of these, 32% were actively detected and 68% passively detected. Most alerts (90%) required no intervention and 10% of alerts had an intervention. There were 25% investigations that were not carried out despite thresholds being met; 17% interventions were not performed, the main reported reason being PUC operational capacity was exceeded. Confirmed cholera and measles outbreaks that met an investigation threshold comprised respectively 90% and 76% of alerts; 59% of measles investigations were followed by a delayed outbreak response of ⩾14 days (n = 10 outbreaks). CONCLUSION: Some alerts for cholera and measles outbreaks that were detected in the PUC system did not lead to a response even when required; the main reported reason was limited operational capacity to respond to all of them.

Protracted cholera outbreak in the Central Region, Ghana, 2016.

OBJECTIVE: On 24th October 2016, the Central Regional Health Directorate received report of a suspected cholera outbreak in the Cape Coast Metropolis (CCM). We investigated to confirm the diagnosis, identify risk factors and implement control measures. DESIGN: We used a descriptive study followed by 1:2 unmatched case-control study. DATA SOURCE: We reviewed medical records, conducted active case search and contact tracing, interviewed case-patients and their contacts and conducted environmental assessment. Case-patients' stool samples were tested with point of care test kits (SD Bioline Cholera Ag 01/0139) and sent to the Cape Coast Teaching Hospital Laboratory for confirmation. MAIN OUTCOMES: Cause of outbreak, risk factors associated with spread of outbreak. RESULTS: Vibrio cholerae serotype Ogawa caused the outbreak. There was no mortality. Of 704 case-patients, 371(52.7%) were males and 55(7.8%) were aged under-five years. The median age was 23 years (interquartile range: 16-32 years). About a third 248(35.2%) of the case patients were aged 15-24 years. The University of Cape Coast subdistrict was the epicenter with 341(48.44%) cases. Compared to controls, cholera case-patients were more likely to have visited Cholera Treatment Centers (CTC) (aOR=12.1, 95%CI: 1.5-101.3), drank pipe-borne water (aOR=11.7, 95%CI: 3.3-41.8), or drank street-vended sachet water (aOR=11.0, 95%CI: 3.7-32.9). Open defecation and broken sewage pipes were observed in the epicenter. CONCLUSION: Vibrio cholerae serotype Ogawa caused the CCM cholera outbreak mostly affecting the youth. Visiting CTC was a major risk factor. Prompt case-management, contact tracing, health education, restricting access to CTC and implementing water sanitation and hygiene activities helped in the control. FUNDING: This work was supported by Ghana Field Epidemiology and Laboratory Training Program (GFELTP), University of Ghana.

A cholera transmission model incorporating the impact of medical resources.

We propose a mathematical model for the transmission dynamics of cholera under the impact of available medical resources. The model describes the interaction between the human hosts and the pathogenic bacteria and incorporates both the environment-to-human and human-to-human transmission routes. We conduct a rigorous equilibrium analysis to the model and establish the global asymptotic stability of the disease-free equilibrium when R0 ≤ 1 and that of the endemic equilibrium when R0 > 1. As a realistic case study, we apply our model to the Yemen cholera outbreak during 2017-2018. By fitting our simulation results to the epidemic data published by the World Health Organization, we find that different levels of disease prevalence and severity are linked to different geographical regions in this country and that cholera prevention and intervention efforts should be implemented strategically with respect to these regions in Yemen.

A case-control study to assess risk factors related to cholera outbreak in Addis Ababa, Ethiopia, July 2016.

INTRODUCTION: Suspected cholera cases were reported to the city administration health bureau in Addis-Ababa, Ethiopia on June 5, 2016 and it was laboratory confirmed by culture on 7 June 2016. The outbreak was declared by the government on June 8, 2016. The aim of this study was to rapidly investigate the outbreak epidemiologically and guide response activities in the affected Sub cities of Addis Ababa city administration. METHODS: An unmatched 1:2 case-control study was conducted in six selected sub-cities of the city administration. Different laboratory tests were also done from suspected possible risk factors identified to support the epidemiological findings. A case was a patient greater than 5 years old, who developed acute watery diarrhea with or without Vomiting. Control was an individual greater than 5 years' old who stayed in the same township and did not suffer from cholera. A structured questionnaire was used to select cases and controls. Epi InfoTM statistical software was used to analyze the data. Results were presented in narratives, figures and tables. RESULTS: The present study found that, the study participants who used street-vended water (Odds Ratio (OR)=10.4; 95% CI: 1.20-90.9), those who reported holy water sources use (OR=2.7, 95% CI: 1.45-5.04), eating raw meat (OR=7.75; 95% CI: 3.86-15.54) or roasted meat (OR=2.16; 95% CI: 1.19-3.93) and vegetable salad (OR=2.07; 95% CI: 1.14-3.76) were associated with contracting cholera infection. The likelihood of contracting cholera was significantly higher among those who ate food from street vendor sources (OR=5.32; 95% CI: 1.82-15.56) and those who practiced open defecation (OR=8.12; 95% CI (2.20-29.81). Having a latrine (OR=0.29; 95% CI: 0.12-0.69) and proper hand hygiene practice (OR=0.22; 95% CI: 0.14-0.38) were found to be protective against cholera infection. CONCLUSION: Improving awareness of the community by intensifying social mobilization activities through community participation in proper hygienic practice, proper waste disposal and latrine facility construction and utilization. Provision of safe water for the community by strictly conducting end-point assessment of water points and conducting a KAP assessment among food handlers to explore their knowledge and practices regarding safe food/drink handling and water treatment as well as initiate appropriate PH actions based on the findings which will be necessary for prevention of similar cholera outbreaks in the future.

Aeromonas caviae mimicking Vibrio cholerae infectious enteropathy in a cholera-endemic region with possible public health consequences: two case reports.

BACKGROUND: Aeromonas species have been documented to yield false positive results in microbiological tests for Vibrio cholerae. They share many biochemical properties with Vibrio species, with which they were jointly classified in the family Vibrionaceae until genotypic information provided new insights. Aeromonas species are increasingly associated with gastrointestinal infections, albeit with great apparent variation in pathogenicity and virulence both between and within species of the genus. We report two cases with clinically mild cholera-like symptoms, at a time when a cholera outbreak was unfolding in other regions of the country (Tanzania). These are the first cases to be reported with Aeromonas mimicking cholera in our area. CASE PRESENTATION: Two patients were admitted at the isolation unit designated by the Kilimanjaro Christian Medical Centre for emerging infectious diseases and provided informed consent about regular stool analysis and culture under the provisional diagnosis of gastroenteritis. The first patient was a 23-year-old black African woman with a 2-day history of watery diarrhea and vomiting associated with a temperature of 39.7 °C. The second patient was a 47-year-old black African woman with a 2-day history of diarrhea and vomiting with a temperature of 37.7 °C, and she was hemodynamically stable. Both patients were isolated in a specific area for infection control and treated with fluids and orally administered rehydration solution, ciprofloxacin, metronidazole, and paracetamol. Stool culture was done. The isolated colonies were reported as V. cholerae and transferred to the research laboratory of Kilimanjaro Clinical Research Institute for confirmation using whole genome sequencing. Microbiological testing determined colonies isolated from stool to be V. cholerae, and warranted the conclusion "presumptive cholera." Whole genome sequencing, however, established the presence of Aeromonas caviae rather than V. cholerae. CONCLUSIONS: The co-existence of Aeromonas species with V. cholerae in cholera-endemic regions suggests the possibility that a proportion of suspected cholera cases may be Aeromonas infections. However, with close to no epidemiological data available on Aeromonas infection in cases of diarrhea and dysentery in Sub-Saharan Africa, it is not currently possible to establish the extent of misdiagnosis to any degree of certainty. Whole genome sequencing was shown to readily exclude V. cholerae as the etiological agent and establish the presence of Aeromonas species.