Epidemiology Of Cholera Research Articles

Cholera Outbreaks in Low- and Middle-Income Countries in the Last Decade: A Systematic Review and Meta-Analysis

Cholera is linked to penury, making low- and middle-income countries (LMICs) particularly vulnerable to outbreaks. In this systematic review, we analyzed the drivers contributing to these outbreaks, focusing on the epidemiology of cholera in LMICs. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in PROSPERO (ID: CRD42024591613). We searched PubMed, Scopus, Web of Science, and Google Scholar to include studies on cholera outbreaks that occurred in LMICs from 1 January 2014 to 21 September 2024. Studies on outbreaks outside LMICs and focusing on sporadic cases were excluded. The risk of bias among included studies was assessed using a modified Downes et al. appraisal tool. Thematic analysis was used to synthesize the qualitative data, and meta-analyses to estimate the pooled prevalence. From 1662 records, 95 studies met inclusion criteria, primarily documenting outbreaks in Africa (74%) and Asia (26%). Contaminated water was the main route of disease transmission. The pooled fatality prevalence was 1.3% (95% CI: 1.1–1.6), and the detection rate among suspected cases was 57.8% (95% CI: 49.2–66.4). Vibrio cholerae O1 was the dominant serogroup while Ogawa was the dominant serotype. All studies reporting biotypes indicated El Tor. Although the isolates were 100% susceptible to ofloxacin, levofloxacin, norfloxacin, cefuroxime, and doxycycline, they were also fully resistant to amikacin, sulfamethoxazole, trimethoprim, and furazolidone. The persistence of cholera outbreaks in destitute areas with limited access to clean water and sanitation emphasizes the need for socioeconomic improvements, infrastructure development, and ongoing surveillance to support timely responses and achieve long-term prevention.

Diarrhea and cholera surveillance for early warning and preparedness to prevent epidemics among Rohingya Myanmar nationals in Cox's Bazar, Bangladesh

Diarrheal diseases, especially cholera, can be a serious threat to Rohingya refugees in Cox's Bazar due to overcrowding and inadequate hygiene infrastructure. Assessing the risk, cholera surveillance network was established with the aim to identify the outbreak of diarrhea and cholera and help to take appropriate preventive measures including a vaccination campaign. The surveillance network has been ongoing for 6 years (2017–2023) in 17 health facilities. Diarrhea patients from Rohingya Myanmar nationals matched with case definition were enrolled and stool samples were tested by Rapid diagnostic test (RDT) for early cholera detection Multiple Logistic regression models were fitted to examine the associations of risk factors among cholera cases. A total of 17,252 stool samples were collected through surveillance. Among the tested samples, 588 (3.5 %) were detected positive by RDT, and 239 (1.4 %) Vibrio cholerae were isolated by microbiological culture. Between 2021 and 2023, the number of culture-confirmed cases exceeded that in the period from 2017 to 2020. In addition to V. cholerae; high positivity was identified for ETEC (11.8 %) followed by Salmonella (3.9 %) and Shigella (2.7 %). Most of the cholera cases were presented with vomiting, dehydration and loose watery and rice watery nature of stool (p value = <0.001). Major risk factors for cholera were 2–4 years age group (OR = 5.72; 95 % CI, 3.84–8.53.14; P = .001), process of water treatment (OR = 1.54; 95 % CI, 1.01–2.37; P = .046) and hand washing with soap before taking meals (OR = 0.6; 95 % CI, 0.39–0.92; P = .020. This study highlights the epidemiology of cholera among the Rohingya population and underscores the effectiveness of integrating surveillance data with early warning, alert, and response systems (EWARS) system, along with oral cholera vaccine (OCV) campaigns, in preventing major cholera outbreak.

An unusual two-strain cholera outbreak in Lebanon, 2022-2023: a genomic epidemiology study

Cholera is a life-threatening gastrointestinal infection caused by a toxigenic bacterium, Vibrio cholerae. After a lull of almost 30 years, a first case of cholera was detected in Lebanon in October 2022. The outbreak lasted three months, with 8007 suspected cases (671 laboratory-confirmed) and 23 deaths. In this study, we use phenotypic methods and microbial genomics to study 34 clinical and environmental Vibrio cholerae isolates collected throughout this outbreak. All isolates are identified as V. cholerae O1, serotype Ogawa strains from wave 3 of the seventh pandemic El Tor (7PET) lineage. Phylogenomic analysis unexpectedly reveals the presence of two different strains of the seventh pandemic El Tor (7PET) lineage. The dominant strain has a narrow antibiotic resistance profile and is phylogenetically related to South Asian V. cholerae isolates and derived African isolates from the AFR15 sublineage. The second strain is geographically restricted and extensively drug-resistant. It belongs to the AFR13 sublineage and clusters with V. cholerae isolates collected in Yemen. In conclusion, the 2022-2023 Lebanese cholera outbreak is caused by the simultaneous introduction of two different 7PET strains. Genomic surveillance with cross-border collaboration is therefore crucial for the identification of new introductions and routes of circulation of cholera, improving our understanding of cholera epidemiology.

Retrospective Analysis of Cholera/Acute Watery Diarrhea Outbreaks in Ethiopia From 2001 To 2023: Incidence, Case Fatality Rate, and Seasonal and Multiyear Epidemic Patterns.

The Ethiopian government has developed the multisectoral cholera elimination plan (NCP) with an aim of reducing cholera incidence and case fatality rate (CFR). To better understand and monitor the progress of this plan, a comprehensive review of national cholera epidemiology is needed. Reported data on cholera/acute watery diarrhea (AWD) cases in the past 20 years were extracted from the Ethiopian Public Health Institute and World Health Organization databases. Descriptive statistics, Pearson χ2, and logistic regression analyses were conducted. From January 2001 to November 2023, a total of 215 205 cholera/AWD cases, 2355 deaths with a cumulative CFR of 1.10% (95% confidence interval [CI], 1.092-1.095), and a mean annual incidence rate of 8.9/100 000 (95% CI, 6.5-11.3) were reported. Two major upsurges of cholera epidemics were found in the last two decades with mean attack rate (AR) of 20.57/100 000 in 2006-2010 and 14.83/100 000 in 2016-2020. Another resurgence of outbreaks occured in 2021-2023 (mean AR, 8.63/100 000). In 2015-2023, 54.0% (53 990/99 945) of cases were aged 15-44 years. National cholera CFR (3.13% [95% CI: 2.1-4.5]) was the highest in 2022. The 2015-2023 cumulative cholera CFR was different across regions: Benishangul Gumuz (6.07%), Gambela (1.89%), Sidama (1.42%), Southern Nation, Nationalities, and Peoples' (1.34%), Oromia (1.10%), and Amhara (1.09%). Cholera/AWD patients in older adults (≥45 years), severe dehydration, peak rainy season (June-August), and outpatients were associated with higher risk of death. Cholera has been a public health problem in Ethiopia with case fatalities still above the global target. Case management needs to be improved particularly in outpatients and older populations. Outbreak preparedness should be rolled out well in advance of the typical rainy seasons. Significant investments are essential to advance the cholera surveillance system at healthcare setting and community level. Underlying factors of cholera deaths per areas should be further investigated to guide appropriate interventions to meet the NCP target by 2028.

Spatiotemporal dynamics of cholera epidemics in Ethiopia: 2015–2021

Since the onset of the seventh cholera pandemic, Ethiopia has been affected by recurrent epidemics. However, the epidemiology of cholera in this country remains poorly understood. This study aimed to describe cholera outbreak characteristics in Ethiopia from 2015 to 2021. During this period, Ethiopia experienced four epidemic waves. The first wave involved nationwide outbreaks during the second half of 2016 followed by outbreaks predominantly affecting Somali Region in 2017. The second wave primarily affected Tigray and Afar Regions. During the third wave, multiple smaller-scale outbreaks occurred during 2019. The fourth wave was limited to Bale Zone (Oromia Region) in 2021. Overall, a north to south shift was observed over the course of the study period. Major cholera transmission factors included limited access to safe water and sanitation facilities. Severe weather events (drought and flooding) appear to aggravate cholera diffusion. Cholera transmission between Ethiopia and nearby countries (Kenya and Somalia), likely plays a major role in regional cholera dynamics. Overall, this study provides the first understanding of recent spatiotemporal cholera dynamics in Ethiopia to inform cholera control and elimination strategies.

Congruity of genomic and epidemiological data in modelling of local cholera outbreaks.

Cholera continues to be a global health threat. Understanding how cholera spreads between locations is fundamental to the rational, evidence-based design of intervention and control efforts. Traditionally, cholera transmission models have used cholera case-count data. More recently, whole-genome sequence data have qualitatively described cholera transmission. Integrating these data streams may provide much more accurate models of cholera spread; however, no systematic analyses have been performed so far to compare traditional case-count models to the phylodynamic models from genomic data for cholera transmission. Here, we use high-fidelity case-count and whole-genome sequencing data from the 1991 to 1998 cholera epidemic in Argentina to directly compare the epidemiological model parameters estimated from these two data sources. We find that phylodynamic methods applied to cholera genomics data provide comparable estimates that are in line with established methods. Our methodology represents a critical step in building a framework for integrating case-count and genomic data sources for cholera epidemiology and other bacterial pathogens.

Inferring the proportion of undetected cholera infections from serological and clinical surveillance in an immunologically naive population.

Most infections with pandemic Vibrio cholerae are thought to result in subclinical disease and are not captured by surveillance. Previous estimates of the ratio of infections to clinical cases have varied widely (2 to 100 infections per case). Understanding cholera epidemiology and immunity relies on the ability to translate between numbers of clinical cases and the underlying number of infections in the population. We estimated the infection incidence during the first months of an outbreak in a cholera-naive population using a Bayesian vibriocidal antibody titer decay model combining measurements from a representative serosurvey and clinical surveillance data. 3,880 suspected cases were reported in Grande Saline, Haiti, between 20 October 2010 and 6 April 2011 (clinical attack rate 18.4%). We found that more than 52.6% (95% Credible Interval (CrI) 49.4-55.7) of the population ≥2 years showed serologic evidence of infection, with a lower infection rate among children aged 2-4 years (35.5%; 95%CrI 24.2-51.6) compared with people ≥5 years (53.1%; 95%CrI 49.4-56.4). This estimated infection rate, nearly three times the clinical attack rate, with underdetection mainly seen in those ≥5 years, has likely impacted subsequent outbreak dynamics. Our findings show how seroincidence estimates improve understanding of links between cholera burden, transmission dynamics and immunity.

Occurrence of virulence determinants in vibrio cholerae, vibrio mimicus, vibrio alginolyticus, and vibrio parahaemolyticus isolates from important water resources of Eastern Cape, South Africa

BackgroundVirulence determinants are crucial to the risk assessment of pathogens in an environment. This study investigated the presence of eleven key virulence-associated genes in Vibrio cholerae (n = 111) and Vibrio mimicus (n = 22) and eight virulence determinants in Vibrio alginolyticus (n = 65) and Vibrio parahaemolyticus (n = 17) isolated from six important water resources in Eastern Cape, South Africa, using PCR techniques. The multiple virulence gene indexes (MVGI) for sampling sites and isolates as well as hotspots for potential vibriosis outbreaks among sampling sites were determined statistically based on the comparison of MVGI.ResultThe PCR assay showed that all the V. cholerae isolates belong to non-O1/non-O139 serogroups. Of the isolates, Vibrio Cholera (84%), V. mimicus (73%), V. alginolyticus (91%) and V. parahaemolyticus (100%) isolates harboured at least one of the virulence-associated genes investigated. The virulence gene combinations detected in isolates varied at sampling site and across sites. Typical virulence-associated determinants of V. cholerae were detected in V. mimicus while that of V. parahaemolyticus were detected in V. alginolyticus. The isolates with the highest MVGI were recovered from three estuaries (Sunday river, Swartkopps river, buffalo river) and a freshwater resource (Lashinton river). The cumulative MVGI for V. cholerae, V. mimicus, V. alginolyticus and V. parahaemolyticus isolates were 0.34, 0.20, 0.45, and 0.40 respectively. The targeted Vibrio spp. in increasing order of the public health risk posed in our study areas based on the MVGI is V. alginolyticus > V. parahaemolyticus > V. cholerae > V. mimicus. Five (sites SR, PA5, PA6, EL4 and EL6) out of the seventeen sampling sites were detected as the hotspots for potential cholera-like infection and vibriosis outbreaks.ConclusionsOur findings suggest that humans having contact with water resources in our study areas are exposed to potential public health risks owing to the detection of virulent determinants in human pathogenic Vibrio spp. recovered from the water resources. The study affirms the relevancy of environmental Vibrio species to the epidemiology of vibriosis, cholera and cholera-like infections. Hence we suggest a monitoring program for human pathogenic Vibrio spp. in the environment most especially surface water that humans have contact with regularly.

Cholera: An Overview with Reference to the Syrian Outbreak.

Cholera is an acute type of diarrheal disease caused by intestinal infection with the toxin-producing bacteria Vibrio cholerae. The disease is still endemic in almost 69 countries, accounting for around 2.86 million cases and 95,000 deaths annually. Cholera is associated with poor infrastructure, and lack of access to sanitation and clean drinking water. The current cholera outbreak in Syria is associated with more than 10 years of conflict, which has devastated infrastructures and health services. There were 132,782 suspected cases reported between August 25, 2022 and May 20, 2023 in all 14 governorates, including 104 associated deaths. The recent earthquake in the region has complicated the situation, with an increase in cholera cases, and hindrance to a response to the disease. Climate change has driven a number of large cholera outbreaks around the world this year. The World Health Organization prequalifies three oral cholera vaccines. Cholera treatment mainly depends on rehydration, with the use of antibiotics in more severe infections. This review gives an overview of cholera bacteriology, pathogenesis, epidemiology, clinical manifestations, diagnosis, management, and prevention in light of global climate change and the ongoing outbreak in Syria, which poses a significant public health threat that requires urgent attention.

Estimating the proportion of clinically suspected cholera cases that are true Vibrio cholerae infections: A systematic review and meta-analysis.

Cholera surveillance relies on clinical diagnosis of acute watery diarrhea. Suspected cholera case definitions have high sensitivity but low specificity, challenging our ability to characterize cholera burden and epidemiology. Our objective was to estimate the proportion of clinically suspected cholera that are true Vibrio cholerae infections and identify factors that explain variation in positivity. We conducted a systematic review of studies that tested ≥10 suspected cholera cases for V. cholerae O1/O139 using culture, PCR, and/or a rapid diagnostic test. We searched PubMed, Embase, Scopus, and Google Scholar for studies that sampled at least one suspected case between January 1, 2000 and April 19, 2023, to reflect contemporary patterns in V. cholerae positivity. We estimated diagnostic test sensitivity and specificity using a latent class meta-analysis. We estimated V. cholerae positivity using a random-effects meta-analysis, adjusting for test performance. We included 119 studies from 30 countries. V. cholerae positivity was lower in studies with representative sampling and in studies that set minimum ages in suspected case definitions. After adjusting for test performance, on average, 52% (95% credible interval (CrI): 24%, 80%) of suspected cases represented true V. cholerae infections. After adjusting for test performance and study methodology, the odds of a suspected case having a true infection were 5.71 (odds ratio 95% CrI: 1.53, 15.43) times higher when surveillance was initiated in response to an outbreak than in non-outbreak settings. Variation across studies was high, and a limitation of our approach was that we were unable to explain all the heterogeneity with study-level attributes, including diagnostic test used, setting, and case definitions. In this study, we found that burden estimates based on suspected cases alone may overestimate the incidence of medically attended cholera by 2-fold. However, accounting for cases missed by traditional clinical surveillance is key to unbiased cholera burden estimates. Given the substantial variability in positivity between settings, extrapolations from suspected to confirmed cases, which is necessary to estimate cholera incidence rates without exhaustive testing, should be based on local data.

Outbreak of Cholera in Ghana: A Systematic Review from 2010 to 2020

Background: Cholera affects several hundred thousand individuals worldwide each year. According to estimates, more than 20 million individuals in Ghana are at danger of contracting the illness. However, research from Asia and other continents continues to be a major source of information for understanding cholera epidemiology in Africa, particularly in its coastal nations. The purpose of the study was to evaluate Ghana's cholera epidemics each year.&#x0D; Methods: A thorough analysis of articles that have been published on cholera outbreaks worldwide and in Ghana. A thorough search was done in the databases of Science Direct, PubMed, and Google Scholar to retrieve and to review research works published on cholera.&#x0D; Results: Findings suggest cholera has been a significant public health issue for Ghana every year since the first case was reported in 1970. Greater Accra is the area with the most cholera cases each year, with Accra being the district with the most cases. Greater Accra alone reported 58.5% of all cholera cases in Ghana from 1998 to 2017. However, the least affected regions in Ghana are the Upper West, Northern, Upper East, and Volta region. The cause of these cholera outbreaks is subpar sanitation and contaminated water. Annual cholera outbreaks occur in Ghana, where more attention is needed. Multiple deaths have been caused by these epidemics.&#x0D; Conclusion: Improved sanitation and provision of adequate clean drinking water can help curb the incidence of cholera and its devastating effects on individuals and the country as a whole.

A minireview of cholera outbreak in Lebanon - a rising public health concern.

Cholera is a highly contagious illness that can cause severe, acute, watery diarrhea. The WHO and the Lebanese Ministry of Health announced on the 10 October 2022 the re-emergence of Cholera in Lebanon. Data was collected from the Ministry of Public Health in Lebanon, the WHO, news announcements, as well as from online databases such as PubMed, Science Direct, news, conferences, and press releases on the current cholera outbreak. More than 669 confirmed cholera cases and 23 deaths have been reported in Lebanon up until 29 December 2022. The Ministry of Public Health is providing cooperation and support in containing the disease and covering the hospital and treatment expenses for cholera patients. This paper aims to study the epidemiology of cholera, focusing on the most recent cholera outbreak in Lebanon, and to suggest some recommendations that can be followed to fight off this outbreak.

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

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

Mythological Endings: John Snow (1813–1858) and the History of American Epidemiology

During the COVID-19 epidemic, the name of the 19th-century English physician John Snow (1813-1858) has cropped up to a surprising extent, notably in connection with the severe cholera epidemic of 1854 in the district of Golden Square, London. It is repeatedly stated that Snow brought this epidemic of waterborne disease to an end by removing the handle of the Broad Street pump. It is also widely known that this story is a myth. Nonetheless, the Broad Street pump story as told by Snow's close friend Benjamin Ward Richardson remains embedded, partly, it is argued, because of its appeal to areas of the cultural consciousness. In America, Snow and his work on the epidemiology of cholera, including the Broad Street pump story, achieved a serious status which has endured, in one form or another, to the present day. In contrast to Britain, the heroic age of public health in America coincided with the optimism of the bacteriological revolution and higher hopes for medical science. However, this rapidly changing environment exacerbated differences of opinion as to what the small and emergent specialty of epidemiology should look like, what its project was, and where it should be based. Different versions of Snow's persona came to represent basic and often conflicting conceptions of epidemiology and the status (or lack of it) of its practitioners. For many, consciously or otherwise, the removal of the Broad Street pump handle remained an individualistic triumph, a single human intervention which resembled modern medicine in providing a “cure.”

Contribution of microbial genomics to cholera epidemiology.

In 2022, the burden of cholera-an acute watery diarrheal disease caused by Vibrio cholerae serogroup O1 (or more rarely O139) bacteria, which produce cholera toxin-remains high in many African and Asian countries. In the last few years, microbial genomics has made it possible to define the bacterial populations responsible for cholera more precisely. It has been shown that the current, seventh pandemic is due to a single lineage with a reservoir in the countries of the Bay of Bengal (India and Bangladesh). There have been several transmissions of the causal agent of cholera from this region to Africa, Asia and Latin America, suggesting a human-to-human transmission of the disease. Microbial genetics can help to fight this scourge by providing insight into cholera epidemiology and through its use in disease monitoring, thereby contributing to the achievement of the World Health Organization's goal of reducing cholera deaths by 90% by 2030.

Accessing sub-national cholera epidemiological data for Nigeria and the Democratic Republic of Congo during the seventh pandemic

BackgroundVibrio cholerae is a water-borne pathogen with a global burden estimate at 1.4 to 4.0 million annual cases. Over 94% of these cases are reported in Africa and more research is needed to understand cholera dynamics in the region. Cholera data are lacking, mainly due to reporting issues, creating barriers for widespread research on cholera epidemiology and management in Africa.Main bodyHere, we present datasets that were created to help address this gap, collating freely available sub-national cholera data for Nigeria and the Democratic Republic of Congo. The data were collated from a variety of English and French publicly available sources, including the World Health Organization, PubMed, UNICEF, EM-DAT, the Nigerian CDC and peer-reviewed literature. These data include information on cases, deaths, age, gender, oral cholera vaccination, risk factors and interventions.ConclusionThese datasets can facilitate qualitative, quantitative and mixed methods research in these two high burden countries to assist in public health planning. The data can be used in collaboration with organisations in the two countries, which have also collected data or undertaking research. By making the data and methods available, we aim to encourage their use and further data collection and compilation to help improve the data gaps for cholera in Africa.

Assay for Evaluating the Abundance of Vibrio cholerae and Its O1 Serogroup Subpopulation from Water without DNA Extraction.

Cholera is a severe diarrheal disease caused by Vibrio cholerae, a natural inhabitant of brackish water. Effective control of cholera outbreaks depends on prompt detection of the pathogen from clinical specimens and tracking its source in the environment. Although the epidemiology of cholera is well studied, rapid detection of V. cholerae remains a challenge, and data on its abundance in environmental sources are limited. Here, we describe a sensitive molecular quantification assay by qPCR, which can be used on-site in low-resource settings on water without the need for DNA extraction. This newly optimized method exhibited 100% specificity for total V. cholerae as well as V. cholerae O1 and allowed detection of as few as three target CFU per reaction. The limit of detection is as low as 5 × 103 CFU/L of water after concentrating biomass from the sample. The ability to perform qPCR on water samples without DNA extraction, portable features of the equipment, stability of the reagents at 4 °C and user-friendly online software facilitate fast quantitative analysis of V. cholerae. These characteristics make this assay extremely useful for field research in resource-poor settings and could support continuous monitoring in cholera-endemic areas.

Epidemiology of Cholera Outbreak and Summary of the Preparedness and Response Activities in Addis Ababa, Ethiopia, 2016.

Background Cholera is a major public health problem in Ethiopia. This study aimed to generate evidence to better understand the epidemiology of cholera as well as chronicle the city administration's emergency management efforts during the Addis Ababa cholera outbreak in 2016. Method A descriptive analysis was performed using the cholera outbreak data collected from June 8 to October 31, 2016. A case was defined as a patient aged 5 years or older who develops acute watery diarrhea with or without vomiting. Administrative and laboratory finding reports were also used, as well as documented situational updates. Result A total of 8,083 cases (AR of 0.24 percent) with 15 deaths (CFR of 0.18 percent) were reported. Males in unskilled manual occupations and housewives accounted for 2,198 (27.2%) and 1,195 (14.8%), respectively, of the total. A total of 6,908 cases (85.46 percent) sought medical attention within two days of the onset of the condition. The presence of the Kolfie river as well as the relatively confined living conditions of the residents aided in the emergence and rapid spread of the disease. The increased in-and-out movement of people, combined with the city administration's deficient development infrastructure of water, hygiene, and sanitation, contributes to higher morbidity and a longer duration of the outbreak. Multiple command posts established in various locations as well as a lack of collaboration among relevant stakeholders resulted in inefficient information and resource management. Furthermore, there is a lack of risk factor surveillance for the early detection of cholera-causing agents. Conclusion and Recommendations. This outbreak caused significant morbidity and mortality. Prioritizing early risk detection, implementing preventive measures, and developing positive working relationships with relevant parties are all critical. A well-established community-based surveillance system and incident management system (IMS) will be required for future emergency management. It is recommended that the city administration make critical adjustments to its developmental infrastructures related to water, sanitation, and hygiene and implement risk factor surveillance from sewerage lines for the early detection of agents that cause cholera.

Emergence of Vibrio cholerae O1 Sequence Type 75, South Africa, 2018-2020.

We describe the molecular epidemiology of cholera in South Africa during 2018–2020. Vibrio cholerae O1 sequence type (ST) 75 recently emerged and became more prevalent than the V. cholerae O1 biotype El Tor pandemic clone. ST75 isolates were found across large spatial and temporal distances, suggesting local ST75 spread.

Molecular characterization of Vibrio cholerae O1 strains circulating in Assam: a north eastern state of India

Background and Objectives:Information on the genetic epidemiology of cholera in Assam, a northeastern state of India is lacking despite cholera being a major public health problem. The study aimed to determine the virulence genes and genes encoding antibiotic resistance in Vibrio cholerae isolates and to determine the prevalent genotypes based on the presence or absence of the virulence genes and ctxB genotype.Materials and Methods:Twenty-five V. cholerae strains were subjected to conventional biotyping and serotyping followed by multiplex PCR to detect ctxA, ctxB, zot, ace, O1rfb, tcpA, ompU, ompW, rtxC, hly and toxR and antibiotic resistance genes. Cholera toxin B (ctxB) gene was amplified followed by sequencing.Results:All the V. cholerae O1 isolates were El Tor Ogawa and showed the presence of the core toxin region representing the genome of the filamentous bacteriophage CTXø. The complete cassette of virulence genes was seen in 48% of the isolates which was the predominant genotype. All the isolates possessed amino acid sequences identical to the El Tor ctxB subunit of genotype 3. sulII gene was detected in 68% of the isolates, dfrA1 in 88%, strB in 48% and SXT gene was detected in 36% of the isolates.Conclusion:Toxigenic V. cholerae O1 El Tor Ogawa strains of ctxB genotype 3 carrying a large pool of virulence genes are prevailing in Assam. Presence of a transmissible genetic element SXT in 36% of the strains is of major concern as it indicates the emergence of multiple drug resistance among the V. cholerae isolates.