Search Results (26)

Wastewater-based epidemiology (WBE) has historically proven to be a powerful surveillance tool, particularly during the SARS-CoV-2 pandemic. Effective WBE depends on the sensitive detection of pathogens in wastewater. However, determining the process limit of detection (PLOD) of WBE through a comprehensive evaluation that accounts for pathogen concentration, nucleic acid extraction, and molecular analysis has rarely been documented. We prepared dilution series with known concentrations of S. Typhi, V. cholerae, rotavirus, and SARS-CoV-2 in surface water and wastewater. Pathogen concentration was performed using Nanotrap particles with the KingFisher™ Apex robotic platform, followed by nucleic acid extraction. Quantitative real-time PCR (qPCR) and digital PCR (dPCR) were used to detect the extracted nucleic acids of the pathogens. The PLODs and recovery efficiencies for each of the four pathogens in surface water and wastewater were determined. Overall, the observed PLODs for S. Typhi, V. cholerae, and rotavirus in surface water and wastewater were approximately 3 log₁₀ loads (2.1–2.8 × 10³/10 mL) using either qPCR or dPCR as the detection method. For SARS-CoV-2, the PLOD in surface water was 2.9 × 10⁴/10 mL with both RT-qPCR and dPCR, one log₁₀ higher than the PLODs of the other three pathogens. In wastewater, the PLOD for SARS-CoV-2 was 2.9 × 10⁴/10 mL using RT-qPCR and 2.9 × 10³/10 mL using dPCR. The mean recovery rates of S. Typhi, V. cholerae, rotavirus, and SARS-CoV-2 for dPCR in both surface water and wastewater were below 10.4%, except for S. Typhi and V. cholerae in wastewater, which showed significantly higher recoveries, from 26.5% at 4.6 × 10⁵/10 mL for S. Typhi to 58.8% at 4.8 × 10⁵/10 mL for V. cholerae. Our study demonstrated that combining qPCR or dPCR analysis with automated Nanotrap particle concentration and nucleic acid extraction using the KingFisher™ platform enables the sensitive detection of S. Typhi, V. cholerae, rotavirus, and SARS-CoV-2 in surface water and wastewater. Full article

The El Tor biotype of Vibrio cholerae caused the seventh cholera pandemic (7CP). Although V. cholerae variants of this biotype frequently emerge, studies on their microevolution and spatiotemporal transmission in epidemics caused by a single clone are limited. During the cholera outbreak in Sichuan Province, China, in the 1990s, strains belonging to phage type 6 (PT6) but resistant to typing phage VP5 due to a deletion mutation in ompW, which is the gene associated with the VP5 receptor were identified. In this study, we analyzed PT6 strains using genome sequencing to reveal the genomic and transmission characteristics of such a transient phage type in China’s cholera epidemic history. The findings revealed that the PT6 strains formed an independent clone during the four-year epidemic and emerged in wave 2. Most of them carried multiple CTX^classΦ genome copies on chromosome 2 (Chr. 2) and two copies each of RS1^ET and RS1-4** on chromosome 1 (Chr. 1). Frequent cross-regional transmission and local outbreaks within Sichuan Province, China, were revealed for this clone. A variety of spontaneous mutations in the ompW gene, conferring resistance to the VP5 phage, were observed under VP5 infection pressure, showing the incident mutation of OmpW for the survival adaptation of V. cholerae to phage pressure. Therefore, this genomic epidemiological revisit of these distinct phage-resistant phenotype strains reveals their clonal genetic structure, improves our understanding of the spread of V. cholerae by tracking their variation, and assists in epidemic source tracing and disease control. Full article

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. Full article

The lack of a universally accepted definition of a pandemic hinders a comprehensive understanding of and effective response to these global health crises. Current definitions often lack quantitative criteria, rendering them vague and limiting their utility. Here, we propose a refined definition that considers the likelihood of susceptible individuals contracting an infectious disease that culminates in widespread global transmission, increased morbidity and mortality, and profound societal, economic, and political consequences. Applying this definition retrospectively, we identify 22 pandemics that occurred between 165 and 2024 AD and were caused by a variety of diseases, including smallpox (Antonine and American), plague (Justinian, Black Death, and Third Plague), cholera (seven pandemics), influenza (two Russian, Spanish, Asian, Hong Kong, and swine), AIDS, and coronaviruses (SARS, MERS, and COVID-19). This work presents a comprehensive analysis of past pandemics caused by both emerging and re-emerging pathogens, along with their epidemiological characteristics, societal impact, and evolution of public health responses. We also highlight the need for proactive measures to reduce the risk of future pandemics. These strategies include prioritizing surveillance of emerging zoonotic pathogens, conserving biodiversity to counter wildlife trafficking, and minimizing the potential for zoonotic spillover events. In addition, interventions such as promoting alternative protein sources, enforcing the closure of live animal markets in biodiversity-rich regions, and fostering global collaboration among diverse stakeholders are critical to preventing future pandemics. Crucially, improving wildlife surveillance systems will require the concerted efforts of local, national and international entities, including laboratories, field researchers, wildlife conservationists, government agencies and other stakeholders. By fostering collaborative networks and establishing robust biorepositories, we can strengthen our collective capacity to detect, monitor, and mitigate the emergence and transmission of zoonotic pathogens. Full article

Cholera has been a global pandemic in past centuries, and its persistent emergence and spread pose a significant public health challenge globally. Despite efforts to contain the disease, recurrent cholera outbreaks in sub-Saharan Africa remain a major health threat. This has attracted substantial research interest, raising questions about the effectiveness of prevention and control methods of cholera spread in sub-Saharan Africa. Addressing this health challenge by adopting a sustainable, convenient, and cost-effective intervention will improve the health, well-being, and productivity of vulnerable populations in sub-Saharan Africa. Household-level solutions, which are characterized by relatively low-cost and independence from potentially insufficient public water supply infrastructure were examined to determine their effectiveness in reducing the incidence of cholera if widely adopted across the continent. We perform a mixed-methods retrospective analysis on the Cholera epidemic data obtained from 2010 to 2016 in sub-Saharan Africa. Using an empirical epidemiological model, we estimate the performance efficacy of a suite of household water treatment (HWT) technologies. We also develop economic estimations to perform benefit–cost analyses to determine the cost effectiveness, convenience of use and durability of these products. We find that—if universally adopted—the HWT technologies evaluated here offer comparable and effective microbiological potential for eradicating cholera disease in sub-Saharan Africa but are potentially not affordable for low-income households that reside in cholera hotspots. As such, household subsidies are necessary in lowering barriers to economic access to these products. This finding provides substantial insights on the efficacy and affordability of these household water treatment technologies—insights which can inform stakeholder decisions on the applicability of this intervention in eradicating cholera. Full article

A sero-epidemiology study was conducted in Dhaka, Bangladesh between January 2020 and February 2021 to assess the immune responses to ETEC infection in adults and children. (1) Background: Enterotoxigenic Escherichia coli infection is a main cause of diarrheal disease in endemic countries. The characterization of the immune responses evoked by natural infection can guide vaccine development efforts. (2) Methods: A total of 617 adult and 480 pediatric diarrheal patients were screened, and 43 adults and 46 children (below 5 years of age) with an acute ETEC infection completed the study. The plasma samples were analyzed for antibody responses against the ETEC toxins. (3) Results: Heat-stable toxin (ST)-positive ETEC is the main cause of ETEC infection in adults, unlike in children in an endemic setting. We detected very low levels of anti-ST antibodies, and no ST-neutralizing activity. However, infection with ETEC strains expressing the heat-labile toxin (LT) induced systemic antibody responses in less than 25% of subjects. The antibody levels against LTA and LTB, as well as cholera toxin (CT), correlated well. The anti-LT antibodies were shown to have LT- and CT- neutralizing activity. The antibody reactivity against linear LT epitopes did not correlate with toxin-neutralizing activity. (4) Conclusions: Unlike LT, ST is a poor antigen and even adults have low anti-ST antibody levels that do not allow for the detection of toxin-neutralizing activity. Full article

This study aimed to determine the incidence and virulence factor profiling of Vibrio species from hospital wastewater (HWW) and community wastewater effluents. Wastewater samples from selected sites were collected, processed, and analysed presumptively by the culture dependent methods and molecular techniques. A total of 270 isolates were confirmed as Vibrio genus delineating into V. cholerae (27%), V. parahaemolyticus (9.1%), V. vulnificus (4.1%), and V. fluvialis (3%). The remainder (>50%) may account for other Vibrio species not identified in the study. The four Vibrio species were isolated from secondary hospital wastewater effluent (SHWE), while V. cholerae was the sole specie isolated from Limbede community wastewater effluent (LCWE) and none of the four Vibrio species was recovered from tertiary hospital wastewater effluent (THWE). However, several virulence genes were identified among V. cholerae isolates from SHWE: ToxR (88%), hylA (81%), tcpA (64%), VPI (58%), ctx (44%), and ompU (34%). Virulence genes factors among V. cholerae isolates from LCWE were: ToxR (78%), ctx (67%), tcpA (44%), and hylA (44%). Two different genes (vfh and hupO) were identified in all confirmed V. fluvialis isolates. Among V. vulnificus, vcgA (50%) and vcgB (67%) were detected. In V. parahaemolyticus, tdh (56%) and tlh (100%) were also identified. This finding reveals that the studied aquatic niches pose serious potential health risk with Vibrio species harbouring virulence signatures. The distribution of virulence genes is valuable for ecological site quality, as well as epidemiological marker in the control and management of diseases caused by Vibrio species. Regular monitoring of HWW and communal wastewater effluent would allow relevant establishments to forecast, detect, and mitigate any public health threats in advance. Full article

Cholera is a bacterial disease that is commonly transmitted through contaminated water, leading to severe diarrhea and rapid dehydration that can prove fatal if left untreated. The complexity of the disease spread arises from the convergence of several distinct and interrelated factors, which previous research has often failed to consider. A significant scientific limitation of the existing literature is the simplistic assumption of linear or logistic dynamics of the disease spread, thereby impeding a thorough assessment of the effectiveness of control strategies. Since environmental factors are the most influential determinant of Vibrio bacterial growth in nature and are responsible for the resurgence, propagation, and disappearance of cholera epidemics, we have proposed a S-I-R-S model that combines bacterial dynamics with the Allee effect. This model takes into account the environmental influence and allows for a better understanding of the disease dynamics. Our results have revealed the phenomenon of bi-stability, with backward and forward bifurcation. Furthermore, our findings have demonstrated that the Allee effect provides a robust framework for characterizing fluctuations in bacterial populations and the onset of cholera outbreaks. This framework can be used for assessing the effectiveness of control strategies, including regular environmental sanitation programs, adherence to hygiene protocols, and monitoring of unfavorable weather conditions. Full article

Mining and analysis of the big data of Twitter conversations have been of significant interest to the scientific community in the fields of healthcare, epidemiology, big data, data science, computer science, and their related areas, as can be seen from several works in the last few years that focused on sentiment analysis and other forms of text analysis of tweets related to Ebola, E-Coli, Dengue, Human Papillomavirus (HPV), Middle East Respiratory Syndrome (MERS), Measles, Zika virus, H1N1, influenza-like illness, swine flu, flu, Cholera, Listeriosis, cancer, Liver Disease, Inflammatory Bowel Disease, kidney disease, lupus, Parkinson’s, Diphtheria, and West Nile virus. The recent outbreaks of COVID-19 and MPox have served as “catalysts” for Twitter usage related to seeking and sharing information, views, opinions, and sentiments involving both of these viruses. None of the prior works in this field analyzed tweets focusing on both COVID-19 and MPox simultaneously. To address this research gap, a total of 61,862 tweets that focused on MPox and COVID-19 simultaneously, posted between 7 May 2022 and 3 March 2023, were studied. The findings and contributions of this study are manifold. First, the results of sentiment analysis using the VADER (Valence Aware Dictionary for sEntiment Reasoning) approach shows that nearly half the tweets (46.88%) had a negative sentiment. It was followed by tweets that had a positive sentiment (31.97%) and tweets that had a neutral sentiment (21.14%), respectively. Second, this paper presents the top 50 hashtags used in these tweets. Third, it presents the top 100 most frequently used words in these tweets after performing tokenization, removal of stopwords, and word frequency analysis. The findings indicate that tweets in this context included a high level of interest regarding COVID-19, MPox and other viruses, President Biden, and Ukraine. Finally, a comprehensive comparative study that compares the contributions of this paper with 49 prior works in this field is presented to further uphold the relevance and novelty of this work. Full article

Despite the number of cholera outbreaks reported worldwide, only a few cases are recorded among returning European travellers. We describe the case of a 41-year-old male, returning to Italy after a stay in Bangladesh, his origin country, who presented with watery diarrhoea. Vibrio cholerae and norovirus were detected in the patient’s stools via multiplex PCR methods. Direct microscopy, Gram staining, culture and antibiotic susceptibility tests were performed. The isolates were tested using end-point PCR for the detection of potentially enteropathogenic V. cholera. Serotype and cholera toxins identification were carried out. Whole genome sequencing and bioinformatics analysis were performed, and antimicrobial resistance genes identified. A phylogenetic tree with the most similar genomes of databases previously described was built. Sample of the food brought back by the patient were also collected and analysed. The patient was diagnosed with V. cholerae O1, serotype Inaba, norovirus and SARS-CoV-2 concomitant infection. The isolated V. cholerae strain was found to belong to ST69, encoding for cholera toxin, ctxB7 type and was phylogenetically related to the 2018 outbreak in Dhaka, Bangladesh. Adopting a multidisciplinary approach in a cholera non-endemic country ensured rapid and accurate diagnosis, timely clinical management, and epidemiological investigation at national and international level. Full article

Background: Cholera is a large public health issue, especially in countries with limited resources. The aim of the study was to determine trends in global cholera mortality from 1990–2019. Methods: This research is an observational, descriptive epidemiological study. The age-standardized rates (ASRs, per 100,000 population) of cholera mortality from 1990 to 2019 were evaluated through joinpoint regression analysis (by calculating Odds Ratio—OR, with corresponding 95% Confidence Interval—95% CI). Results: From 1990–2019 in the world, the number of deaths due to cholera in both sexes together increased, ranging from 83,045 in 1990 to 117,167 in 2019. During the observed period, there were about 3.0 million deaths due to cholera in the world. In both sexes together in 2019, the cholera mortality rate was the highest in Nigeria (ARS = 39.19) and Central African Republic (ARS = 38.80), followed by populations in Eritrea (ARS = 17.62) and Botswana (ARS = 13.77). Globally, cholera-related mortality significantly decreased in males (AAPC = −0.4%, 95% CI = −0.7 to −0.1), while a stable trend was noted in females (AAPC = −0.1%, 95% CI = −0.4 to 0.2) in the observed period. In the African Region, significantly increasing cholera-related mortality trends were observed both in males and females (AAPC = 1.3% and AAPC = 1.1%, respectively). Conclusions: Cholera mortality showed a constantly increasing trend in the African Region over the last three decades. More efforts in cholera management are necessary for effective response to the growing mortality in developing countries. Full article

Vaccination is a very common topic, but it is rarely raised or discussed with respect to military members. Soldiers are one of the main professional groups to be immunized on a regular basis. The military actively participates in research on new vaccine preparations. This paper presents data from 2018–2021 on vaccination among Polish soldiers. The material obtained from the Central Register of Vaccination for Professional Soldiers was analyzed using descriptive statistical methods. The number of injections performed in a given period depends on the location of the ongoing missions and the vaccination schedule specific to a given Polish Military Contingent. In Poland, soldiers undergo preventive vaccinations in accordance with the scheme developed by the Armed Forces Operational Command, taking into account the specific nature of the service, epidemiological risks and the calendar of current preventive vaccinations. Soldiers serving abroad are immunized against typhoid, hepatitis A, hepatitis B, rabies, measles, tick-borne encephalitis, Japanese encephalitis, polio, diphtheria, meningococcal disease, chickenpox, cholera and yellow fever. Regular vaccinations for soldiers are necessary to minimize the spread of infectious diseases, and they have a beneficial effect upon the effectiveness of military operations. Full article

Tropical diseases (TDs) are among the leading cause of mortality and fatality globally. The emergence and reemergence of TDs continue to challenge healthcare system. Several tropical diseases such as yellow fever, tuberculosis, cholera, Ebola, HIV, rotavirus, dengue, and malaria outbreaks have led to endemics and epidemics around the world, resulting in millions of deaths. The increase in climate change, migration and urbanization, overcrowding, and other factors continue to increase the spread of TDs. More cases of TDs are recorded as a result of substandard health care systems and lack of access to clean water and food. Early diagnosis of these diseases is crucial for treatment and control. Despite the advancement and development of numerous diagnosis assays, the healthcare system is still hindered by many challenges which include low sensitivity, specificity, the need of trained pathologists, the use of chemicals and a lack of point of care (POC) diagnostic. In order to address these issues, scientists have adopted the use of CRISPR/Cas systems which are gene editing technologies that mimic bacterial immune pathways. Recent advances in CRISPR-based biotechnology have significantly expanded the development of biomolecular sensors for diagnosing diseases and understanding cellular signaling pathways. The CRISPR/Cas strategy plays an excellent role in the field of biosensors. The latest developments are evolving with the specific use of CRISPR, which aims for a fast and accurate sensor system. Thus, the aim of this review is to provide concise knowledge on TDs associated with mosquitoes in terms of pathology and epidemiology as well as background knowledge on CRISPR in prokaryotes and eukaryotes. Moreover, the study overviews the application of the CRISPR/Cas system for detection of TDs associated with mosquitoes. Full article

This paper resists the virality of contemporary paranoia by turning to “French epistemology”, a philosophical ethos that embraces uncertainty and complexity by registering the transformative impact of scientific knowledge on thought. Despite its popular uses describing phenomena of communication today, the idea of virality comes from biomedicine. This paper, therefore, investigates the extent to which an epidemiological concept of viral transmission—the disease vector—can comprehend and encourage new possibilities of thought beyond paranoia. Briefly, I attempt to analyze thought as a vector. I pursue this by examining Delaporte’s important, but neglected, study of the 1832 Parisian cholera epidemic. First elucidating his reconstruction of the ways tentative epistemological progress intertwined with and supported projects of working-class and colonial control. My vectorial analysis then considers how his argument infects contemporary readers with doubts that undo the bases of paranoia. I pursue this analysis further via a methodological examination of Delaporte’s study as both carrier of predecessors’ methods and host in which they alter, becoming newly infectious. I conclude by reflecting on this formulation of thought as disease vector and what Delaporte’s singular treatment of the problem of error reveals about an ethos committed to registering the impact of knowledge on thought. Full article

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. Full article