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1.
BMJ Open ; 14(4): e079776, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38582533

RESUMEN

BACKGROUND: The last 3 years have witnessed global health challenges, ranging from the pandemics of COVID-19 and mpox (monkeypox) to the Ebola epidemic in Uganda. Public health surveillance is critical for preventing these outbreaks, yet surveillance systems in resource-constrained contexts struggle to provide timely disease reporting. Although community health workers (CHWs) support health systems in low-income and middle-income countries (LMICs), very little has been written about their role in supporting public health surveillance. This review identified the roles, impacts and challenges CHWs face in public health surveillance in 25 LMICs. METHODS: We conducted a scoping review guided by Arksey and O'Malley's framework. We exported 1,156 peer-reviewed records from Embase, Global Health and PubMed databases. After multiple screenings, 29 articles were included in the final review. RESULTS: CHWs significantly contribute to public health surveillance in LMICs including through contact tracing and patient visitation to control major infectious diseases such as HIV/AIDS, malaria, tuberculosis, Ebola, neglected tropical diseases and COVID-19. Their public health surveillance roles typically fall into four main categories including community engagement; data gathering; screening, testing and treating; and health education and promotion. The use of CHWs in public health surveillance in LMICs has been impactful and often involves incorporation of various technologies leading to improved epidemic control and disease reporting. Nonetheless, use of CHWs can come with four main challenges including lack of education and training, lack of financial and other resources, logistical and infrastructural challenges as well as community engagement challenges. CONCLUSION: CHWs are important stakeholders in surveillance because they are closer to communities than other healthcare workers. Further integration and training of CHWs in public health surveillance would improve public health surveillance because CHWs can provide health data on 'hard-to-reach' populations. CHWs' work in public health surveillance would also be greatly enhanced by infrastructural investments.


Asunto(s)
COVID-19 , Fiebre Hemorrágica Ebola , Humanos , Países en Desarrollo , Agentes Comunitarios de Salud/educación , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Vigilancia en Salud Pública , COVID-19/epidemiología , COVID-19/prevención & control
2.
bioRxiv ; 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38562792

RESUMEN

Zoonotic pathogens pose a significant risk to human health, with spillover into human populations contributing to chronic disease, sporadic epidemics, and occasional pandemics. Despite the widely recognized burden of zoonotic spillover, our ability to identify which animal populations serve as primary reservoirs for these pathogens remains incomplete. This challenge is compounded when prevalence reaches detectable levels only at specific times of year. In these cases, statistical models designed to predict the timing of peak prevalence could guide field sampling for active infections. Here we develop a general model that leverages routinely collected serosurveillance data to optimize sampling for elusive pathogens. Using simulated data sets we show that our methodology reliably identifies times when pathogen prevalence is expected to peak. We then apply our method to two putative Ebolavirus reservoirs, straw-colored fruit bats (Eidolon helvum) and hammer-headed bats (Hypsignathus monstrosus) to predict when these species should be sampled to maximize the probability of detecting active infections. In addition to guiding future sampling of these species, our method yields predictions for the times of year that are most likely to produce future spillover events. The generality and simplicity of our methodology make it broadly applicable to a wide range of putative reservoir species where seasonal patterns of birth lead to predictable, but potentially short-lived, pulses of pathogen prevalence.

3.
Pediatr Res ; 95(2): 488-495, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37903937

RESUMEN

Ebola disease is a severe disease with extremely high case-fatality rates ranging from 28-100%. Observations made during the 2013-2016 West African epidemic improved our understanding of the clinical course of Ebola disease and accelerated the study of therapeutic and preventative strategies. The epidemic also highlighted the unique challenges associated with providing optimal care for children during Ebola disease outbreaks. In this review, we outline current understanding of Ebola disease epidemiology, pathogenesis, management, and prevention, highlighting data pertinent to the care of children. IMPACT: In this review, we summarize recent advancements in our understanding of Ebola disease epidemiology, clinical presentation, and therapeutic and preventative strategies. We highlight recent data pertinent to the care of children and pregnant women and identify research gaps for this important emerging viral infection in children.


Asunto(s)
Ebolavirus , Epidemias , Fiebre Hemorrágica Ebola , Niño , Humanos , Femenino , Embarazo , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Brotes de Enfermedades/prevención & control , Epidemias/prevención & control
5.
Antiviral Res ; 221: 105764, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38008193

RESUMEN

A majority of viral diseases do not have FDA-approved drugs. The recent outbreaks caused by SARS-CoV-2, monkeypox, and Sudan ebolavirus have exposed the critical need for rapid screening and identification of antiviral compounds against emerging/re-emerging viral pathogens. A high-content screening (HCS) platform is becoming an essential part of the drug discovery process, thanks to developments in image acquisition and analysis. While HCS has several advantages, its full potential has not been realized in antiviral drug discovery compared to conventional drug screening approaches, such as fluorescence or luminescence-based microplate assays. Therefore, this review aims to summarize HCS workflow, strategies, and developments in image-based drug screening, focusing on high-containment viruses.


Asunto(s)
Virosis , Virus , Humanos , Antivirales/farmacología , Descubrimiento de Drogas/métodos , SARS-CoV-2 , Ensayos Analíticos de Alto Rendimiento/métodos
6.
Heliyon ; 9(11): e22138, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38045158

RESUMEN

The incidence of zoonotic diseases, such as coronavirus disease 2019 and Ebola virus disease, is increasing worldwide. However, drug and vaccine development for zoonotic diseases has been hampered because the experiments involving live viruses are limited to high-containment laboratories. The Ebola virus minigenome system enables researchers to study the Ebola virus under BSL-2 conditions. Here, we found that the addition of the nucleocapsid protein of human coronaviruses, such as severe acute respiratory syndrome coronavirus 2, can increase the ratio of green fluorescent protein-positive cells by 1.5-2 folds in the Ebola virus minigenome system. Further analysis showed that the nucleocapsid protein acts as an activator of the Ebola virus minigenome system. Here, we developed an EBOV MiniG Plus system based on the Ebola virus minigenome system by adding the SARS-CoV-2 nucleocapsid protein. By evaluating the antiviral effect of remdesivir and rupintrivir, we demonstrated that compared to that of the traditional Ebola virus minigenome system, significant concentration-dependent activity was observed in the EBOV MiniG Plus system. Taken together, these results demonstrate the utility of adding nucleocapsid protein to the Ebola virus minigenome system to create a powerful platform for screening antiviral drugs against the Ebola virus.

7.
Pan Afr Med J ; 45: 190, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38020355

RESUMEN

Introduction: the number of wild poliomyelitis cases, worldwide, dropped from 350,000 cases in 1988 to 33 in 2018. Acute flaccid paralysis (AFP) surveillance is a key strategy toward achieving global polio eradication. The 2014 Ebola virus disease (EVD) epidemic in West Africa infected over 28,000 people and had devastating effects on health systems in Guinea, Liberia, and Sierra Leone. We sought to assess the effects of the 2014 Ebola outbreak on AFP surveillance in Guinea and Liberia. Methods: a retrospective cross-sectional analysis was performed for Guinea and Liberia to evaluate EVD´s impact on World Health Organization (WHO) AFP surveillance performance indicators during 2012-2015. Results: both Guinea and Liberia met the WHO target non-polio AFP incidence rate nationally, and generally sub-nationally, prior to the EVD outbreak; rates decreased substantially during the outbreak in seven of eight regions in Guinea and 11 of 15 counties in Liberia. Throughout the study period, both Guinea and Liberia attained appropriate overall targets nationally for "notification" and "stool adequacy" indicators, but each country experienced periods of poor regional/county-specific indicator performance. Conclusion: these findings mirrored the negative effect of the Ebola outbreak on polio elimination activities in both countries and highlights the need to reinforce this surveillance system during times of crisis.


Asunto(s)
Fiebre Hemorrágica Ebola , Poliomielitis , Humanos , Fiebre Hemorrágica Ebola/epidemiología , Liberia/epidemiología , Guinea/epidemiología , Estudios Retrospectivos , Estudios Transversales , alfa-Fetoproteínas , Vigilancia de la Población , Poliomielitis/epidemiología , Poliomielitis/prevención & control , Brotes de Enfermedades , Parálisis/epidemiología , Parálisis/etiología
8.
BMC Public Health ; 23(1): 2093, 2023 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-37880607

RESUMEN

BACKGROUND: In the immediate aftermath of a 14-year civil conflict that disrupted the health system, Liberia adopted the internationally recommended integrated disease surveillance and response (IDSR) strategy in 2004. Despite this, Liberia was among the three West African countries ravaged by the worst Ebola epidemic in history from 2014 to 2016. This paper describes successes, failures, strengths, and weaknesses in the development, adoption, and implementation of IDSR following the civil war and up until the outbreak of Ebola, from 2004 to early 2014. METHODS: We reviewed 112 official Government documents and peer-reviewed articles and conducted 29 in-depth interviews with key informants from December 2021 to March 2022 to gain perspectives on IDSR in the post-conflict and pre-Ebola era in Liberia. We assessed the core and supportive functions of IDSR, such as notification of priority diseases, confirmation, reporting, analysis, investigation, response, feedback, monitoring, staff training, supervision, communication, and financial resources. Data were triangulated and presented via emerging themes and in-depth accounts to describe the context of IDSR introduction and implementation, and the barriers surrounding it. RESULTS: Despite the adoption of the IDSR framework, Liberia failed to secure the resources-human, logistical, and financial-to support effective implementation over the 10-year period. Documents and interview reports demonstrate numerous challenges prior to Ebola: the surveillance system lacked key components of IDSR including laboratory testing capacity, disease reporting, risk communication, community engagement, and staff supervision systems. Insufficient financial support and an abundance of vertical programs further impeded progress. In-depth accounts by donors and key governmental informants demonstrate that although the system had a role in detecting Ebola in Liberia, it could not respond effectively to control the disease. CONCLUSION: Our findings suggest that post-war, Liberia's health system intended to prioritize epidemic preparedness and response with the adoption of IDSR. However, insufficient investment and systems development meant IDSR was not well implemented, leaving the country vulnerable to the devastating impact of the Ebola epidemic.


Asunto(s)
Epidemias , Fiebre Hemorrágica Ebola , Humanos , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Liberia/epidemiología , Vigilancia en Salud Pública , Brotes de Enfermedades/prevención & control , Epidemias/prevención & control
9.
PLoS One ; 18(10): e0293077, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37847703

RESUMEN

BACKGROUND: No distinctive clinical signs of Ebola virus disease (EVD) have prompted the development of rapid screening tools or called for a new approach to screening suspected Ebola cases. New screening approaches require evidence of clinical benefit and economic efficiency. As of now, no evidence or defined algorithm exists. OBJECTIVE: To evaluate, from a healthcare perspective, the efficiency of incorporating Ebola prediction scores and rapid diagnostic tests into the EVD screening algorithm during an outbreak. METHODS: We collected data on rapid diagnostic tests (RDTs) and prediction scores' accuracy measurements, e.g., sensitivity and specificity, and the cost of case management and RDT screening in EVD suspect cases. The overall cost of healthcare services (PPE, procedure time, and standard-of-care (SOC) costs) per suspected patient and diagnostic confirmation of EVD were calculated. We also collected the EVD prevalence among suspects from the literature. We created an analytical decision model to assess the efficiency of eight screening strategies: 1) Screening suspect cases with the WHO case definition for Ebola suspects, 2) Screening suspect cases with the ECPS at -3 points of cut-off, 3) Screening suspect cases with the ECPS as a joint test, 4) Screening suspect cases with the ECPS as a conditional test, 5) Screening suspect cases with the WHO case definition, then QuickNavi™-Ebola RDT, 6) Screening suspect cases with the ECPS at -3 points of cut-off and QuickNavi™-Ebola RDT, 7) Screening suspect cases with the ECPS as a conditional test and QuickNavi™-Ebola RDT, and 8) Screening suspect cases with the ECPS as a joint test and QuickNavi™-Ebola RDT. We performed a cost-effectiveness analysis to identify an algorithm that minimizes the cost per patient correctly classified. We performed a one-way and probabilistic sensitivity analysis to test the robustness of our findings. RESULTS: Our analysis found dual ECPS as a conditional test with the QuickNavi™-Ebola RDT algorithm to be the most cost-effective screening algorithm for EVD, with an effectiveness of 0.86. The cost-effectiveness ratio was 106.7 USD per patient correctly classified. The following algorithms, the ECPS as a conditional test with an effectiveness of 0.80 and an efficiency of 111.5 USD per patient correctly classified and the ECPS as a joint test with the QuickNavi™-Ebola RDT algorithm with an effectiveness of 0.81 and a cost-effectiveness ratio of 131.5 USD per patient correctly classified. These findings were sensitive to variations in the prevalence of EVD in suspected population and the sensitivity of the QuickNavi™-Ebola RDT. CONCLUSIONS: Findings from this study showed that prediction scores and RDT could improve Ebola screening. The use of the ECPS as a conditional test algorithm and the dual ECPS as a conditional test and then the QuickNavi™-Ebola RDT algorithm are the best screening choices because they are more efficient and lower the number of confirmation tests and overall care costs during an EBOV epidemic.


Asunto(s)
Fiebre Hemorrágica Ebola , Humanos , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Análisis Costo-Beneficio , Prueba de Diagnóstico Rápido , Sensibilidad y Especificidad , Algoritmos , Pruebas Diagnósticas de Rutina/métodos
10.
Confl Health ; 17(1): 41, 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37649068

RESUMEN

INTRODUCTION: There has been little documentation of the large networks of community health workers that contributed to Ebola Virus Disease (EVD) surveillance during the 2018-2020 Democratic Republic of Congo (DRC) epidemic in the form of community-based surveillance (CBS). These networks, comprised entirely of local community members, were a critical and mostly unrecognized factor in ending the epidemic. Challenges with collection, compilation, and analysis of CBS data have made their contribution difficult to quantify. From November 2019 to March 2020, the DRC Ministry of Health (MoH), the World Health Organization (WHO), and Médecins Sans Frontières (MSF) worked with communities to strengthen existing EVD CBS in two key health areas in Ituri Province, DRC. We describe CBS strengthening activities, detail collaboration with communities and present results of these efforts. We also provide lessons learned to inform future outbreak responses. METHODS: As the foundation of CBS, community health workers (CHW) completed training to identify and report patients who met the EVD alert definitions. Alerts were investigated and if validated, the patient was sent for isolation and EVD testing. Community members provided early and ongoing input to the CBS system. We established a predefined ratio of community- elected CHW, allocated by population, to assure equal and adequate coverage across areas. Strong performing CHW or local leaders managed the CHWs, providing a robust supervision structure. We made additional efforts to integrate rural villages, revised tools to lighten the reporting burden and focused analysis on key indicators. Phased roll-out of activities ensured time for community discussion and approval. An integrated treatment center (ITC) combined EVD testing and isolation with free primary health care (PHC), referral services, and an ambulance network. RESULTS: A total of 247 CHW and supervisors completed training. CBS had a retention rate of 94.3% (n = 233) with an average daily reporting rate of 97.4% (range 75.0-100.0%). Local chiefs and community leaders participated in activities from the early stages. Community feedback, including recommendations to add additional CHW, run separate meetings in rural villages, and strengthen PHC services, improved system coverage and performance. Of 6,711 community referrals made, 98.1% (n = 6,583) were classified as alerts. Of the alerts, 97.4% (n = 6,410) were investigated and 3.0% (n = 190) were validated. Of the community referrals, 73.1% (n = 4,905) arrived for care at the ITC. The contribution of CBS to total alerts in the surveillance system increased from an average of 47.3% in the four weeks prior to system strengthening to 69.0% after. In one of the two health areas, insufficient reporting in rural villages suggested inadequate coverage, with 8.3% of the total population contributing 6.1% of alerts. DISCUSSION: CBS demonstrated the capacity of community networks to improve early disease detection and expand access to healthcare. Early and consistent community involvement proved vital to CBS, as measured by system performance, local acceptance of EVD activities, and health service provision. The CBS system had high reporting rates, number of alerts signaled, proportion of alerts investigated, and proportion of community referrals that arrived for care. The change in contribution of CBS to total alerts may have been due in part to system strengthening, but also to the expansion in the EVD suspect case definition. Provision of PHC, referral services, and an ambulance network linked EVD response activities to the existing health system and facilitated CBS performance. More importantly, these activities provided a continuum of care that addressed community prioritized health needs. The involvement of local health promotion teams was vital to the CBS and other EVD and PHC activities. Lessons learned include the importance of early and consistent community involvement in surveillance activities and the recommendation to assure local representation in leadership positions.

11.
BMJ Glob Health ; 8(8)2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37532462

RESUMEN

INTRODUCTION: Liberia was heavily affected by the 2014-2016 Ebola virus disease (EVD) outbreak. With substantial investments in interventions to combat future outbreaks, it is hoped that Liberia is well prepared for a new incursion. We assessed the performance of the current EVD surveillance system in Liberia, focusing on its ability to promptly detect a new EVD outbreak. METHODS: We integrated WHO and US Centers for Disease Control and Prevention guidelines for public health surveillance system evaluation and used standardised indicators to measure system performance. We conducted 23 key informant interviews, 150 health facility assessment surveys and a standardised patient (SP) study (19 visits) from January 2020 to January 2021. Data were summarised and a gap analysis conducted. RESULTS: We found basic competencies of case detection and reporting necessary for a functional surveillance system were in place. At the higher (national, county and district) levels, we found performance gaps in 2 of 6 indicators relating to surveillance system structure, 3 of 14 indicators related to core functions, 1 of 5 quality indicators and 2 of 8 indicators related to support functions. The health facility assessment found performance gaps in 9 of 10 indicators related to core functions, 5 of 6 indicators related to support functions and 3 of 7 indicators related to quality. The SP simulations revealed large gaps between expected and actual practice in managing a patient warranting investigation for EVD. Major challenges affecting the system's operations across all levels included limited access to resources to support surveillance activities, persistent stock out of sample collection materials and attrition of trained staff. CONCLUSION: The EVD surveillance system in Liberia may fail to promptly detect a new EVD outbreak. Specific improvements are required, and regular evaluations recommended. SP studies could be crucial in evaluating surveillance systems for rarely occurring diseases that are important to detect early.


Asunto(s)
Fiebre Hemorrágica Ebola , Estados Unidos , Humanos , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Liberia/epidemiología , Brotes de Enfermedades/prevención & control , Vigilancia en Salud Pública , Encuestas y Cuestionarios
12.
J Biomol Struct Dyn ; : 1-11, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37477257

RESUMEN

The recent outbreak of the Ebola virus (EBOV) has marked it as one of the most severe health threats globally. Among various anti-EBOV inhibitors studied, galidesivir (BCX4430) has shown remarkable efficacy. This study aims to identify novel potential anti-EBOV drugs among galidesivir analogs, focusing on the Zaire ebolavirus (Z-EBOV), which exhibits a mortality rate of 90%. We subjected 200 candidate compounds to molecular docking calculations, followed by an evaluation of the bioactivity of the top 25 compounds using the OSIRIS Property Explorer. Initial 50 ns molecular dynamics (MD) simulations were then performed. According to our findings, only six compounds exhibited positive drug scores. We further performed molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations of binding energy over 50 ns, selecting the two top-performing compounds for extended 150 ns MD simulations. CID 117698807 and CID 117712809 showed higher binding stability compared to galidesivir, with ΔGbinding values of -36.7 and -53.4 kcal/mol, respectively. Both compounds demonstrated high stability within the Z-EBOV-V24 active site over the 150 ns MD simulations. Hence, our study proposes CID 117698807 and CID 117712809 as potential anti-Z-EBOV-V24 drug candidates, warranting further investigation.Communicated by Ramaswamy H. Sarma.

13.
medRxiv ; 2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36993465

RESUMEN

Background: Lassa fever (LF) is a rodent-borne disease endemic to West Africa. In the absence of licensed therapeutics or vaccines, rodent exclusion from living spaces remains the primary method of preventing LF. Zoonotic surveillance of Lassa virus (LASV), the etiologic agent of LF, can assess the burden of LASV in a region and guide public health measures against LF. Methods: In this study, we adapted commercially available LASV human diagnostics to assess the prevalence of LASV in peri-domestic rodents in Eastern Sierra Leone. Small mammal trapping was conducted in Kenema district, Sierra Leone between November 2018-July 2019. LASV antigen was detected using a commercially available LASV NP antigen rapid diagnostic test. LASV IgG antibodies against LASV nucleoprotein (NP) and glycoprotein (GP) were tested by adapting a commercially available semi-quantitative enzyme linked immunosorbent assay (ELISA) for detection of mouse-related and rat-related species IgG. Findings: Of the 373 tested specimens, 74 (20%) tested positive for LASV antigen. 40 (11%) specimens tested positive for LASV NP IgG, while an additional 12 (3%) specimens only tested positive for LASV GP IgG. Simultaneous antigen presence and IgG antibody presence was linked in Mastomys sp. specimens (p < 0.01), but not Rattus sp. specimens (p = 1). Despite the link between antigen presence and IgG antibody presence in Mastomys sp., the strength of antigen response did not correlate with the strength of IgG response to either GP IgG or NP IgG. Interpretation: The tools developed in this study can aid in the generation of valuable public health data for rapid field assessment of LASV burden during outbreak investigations and general LASV surveillance. Funding: Funding for this work was supported by the National Institute of Allergy and Infectious Diseases National Institute of Health, Department of Health and Human Services under the following grants: International Collaboration in Infectious Disease Research on Lassa fever and Ebola - ICIDR - U19 AI115589, Consortium for Viral Systems Biology - CViSB - 5U19AI135995, West African Emerging Infectious Disease Research Center - WARN-ID - U01AI151812, West African Center for Emerging Infectious Diseases: U01AI151801.

14.
Emerg Infect Dis ; 29(4): 742-750, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36957996

RESUMEN

Human populations that hunt, butcher, and sell bushmeat (bushmeat activities) are at increased risk for zoonotic pathogen spillover. Despite associations with global epidemics of severe illnesses, such as Ebola and mpox, quantitative assessments of bushmeat activities are lacking. However, such assessments could help prioritize pandemic prevention and preparedness efforts. We used geospatial models that combined published data on bushmeat activities and ecologic and demographic drivers to map the distribution of bushmeat activities in rural regions globally. The resulting map had high predictive capacity for bushmeat activities (true skill statistic = 0.94). The model showed that mammal species richness and deforestation were principal drivers of the geographic distribution of bushmeat activities and that countries in West and Central Africa had the highest proportion of land area associated with bushmeat activities. These findings could help prioritize future surveillance of bushmeat activities and forecast emerging zoonoses at a global scale.


Asunto(s)
Animales Salvajes , Fiebre Hemorrágica Ebola , Animales , Humanos , Zoonosis/epidemiología , Zoonosis/etiología , Fiebre Hemorrágica Ebola/epidemiología , Mamíferos , Pandemias
15.
Pathogens ; 12(2)2023 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-36839520

RESUMEN

Since the inception of the ebolavirus in 1976, 32 outbreaks have resulted in nearly 15,350 deaths in more than ten countries of the African continent. In the last decade, the largest (2013-2016) and second largest (2018-2020) ebolavirus outbreaks have occurred in West Africa (mainly Guinea, Liberia, and Sierra Leone) and the Democratic Republic of the Congo, respectively. The 2013-2016 outbreak indicated an alarming geographical spread of the virus and was the first to qualify as an epidemic. Hence, it is imperative to halt ebolavirus progression and develop effective countermeasures. Despite several research efforts, ebolaviruses' natural hosts and secondary reservoirs still elude the scientific world. The primary source responsible for infecting the index case is also unknown for most outbreaks. In this review, we summarize the history of ebolavirus outbreaks with a focus on etiology, natural hosts, zoonotic reservoirs, and transmission mechanisms. We also discuss the reasons why the African continent is the most affected region and identify steps to contain this virus.

16.
Viruses ; 15(2)2023 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-36851690

RESUMEN

Rift Valley fever (RVF) is a febrile vector-borne disease endemic in Africa and continues to spread in new territories. It is a climate-sensitive disease mostly triggered by abnormal rainfall patterns. The disease is associated with high mortality and morbidity in both humans and livestock. RVF is caused by the Rift Valley fever virus (RVFV) of the genus Phlebovirus in the family Phenuiviridae. It is a tripartite RNA virus with three genomic segments: small (S), medium (M) and large (L). Pathogen genomic sequencing is becoming a routine procedure and a powerful tool for understanding the evolutionary dynamics of infectious organisms, including viruses. Inspired by the utility of amplicon-based sequencing demonstrated in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and Ebola, Zika and West Nile viruses, we report an RVFV sample preparation based on amplicon multiplex polymerase chain reaction (amPCR) for template enrichment and reduction of background host contamination. The technology can be implemented rapidly to characterize and genotype RVFV during outbreaks in a near-real-time manner. To achieve this, we designed 74 multiplex primer sets covering the entire RVFV genome to specifically amplify the nucleic acid of RVFV in clinical samples from an animal tissue. Using this approach, we demonstrate achieving complete RVFV genome coverage even from samples containing a relatively low viral load. We report the first primer scheme approach of generating multiplex primer sets for a tripartite virus which can be replicated for other segmented viruses.


Asunto(s)
COVID-19 , Fiebre del Valle del Rift , Virus de la Fiebre del Valle del Rift , Infección por el Virus Zika , Virus Zika , Animales , Humanos , Virus de la Fiebre del Valle del Rift/genética , Reacción en Cadena de la Polimerasa Multiplex , SARS-CoV-2/genética , Genómica , Prueba de COVID-19
19.
J Infect Dis ; 227(7): 878-887, 2023 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-36047331

RESUMEN

BACKGROUND: There is limited evidence to evaluate screening algorithms with rapid antigen testing and exposure assessments as identification strategies for paucisymptomatic or asymptomatic Ebola virus (EBOV) infection and unrecognized EBOV disease (EVD). METHODS: We used serostatus and self-reported postexposure symptoms from a cohort study to classify contact-participants as having no infection, paucisymptomatic or asymptomatic infection, or unrecognized EVD. Exposure risk was categorized as low, intermediate, or high. We created hypothetical scenarios to evaluate the World Health Organization (WHO) case definition with or without rapid diagnostic testing (RDT) or exposure assessments. RESULTS: This analysis included 990 EVD survivors and 1909 contacts, of whom 115 (6%) had paucisymptomatic or asymptomatic EBOV infection, 107 (6%) had unrecognized EVD, and 1687 (88%) were uninfected. High-risk exposures were drivers of unrecognized EVD (adjusted odds ratio, 3.5 [95% confidence interval, 2.4-4.9]). To identify contacts with unrecognized EVD who test negative by the WHO case definition, the sensitivity was 96% with RDT (95% confidence interval, 91%-99%), 87% with high-risk exposure (82%-92%), and 97% with intermediate- to high-risk exposures (93%-99%). The proportion of false-positives was 2% with RDT and 53%-93% with intermediate- and/or high-risk exposures. CONCLUSION: We demonstrated the utility and trade-offs of sequential screening algorithms with RDT or exposure risk assessments as identification strategies for contacts with unrecognized EVD.


Asunto(s)
Ebolavirus , Fiebre Hemorrágica Ebola , Humanos , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Estudios de Cohortes , Brotes de Enfermedades/prevención & control , Medición de Riesgo , Infecciones Asintomáticas/epidemiología
20.
Pan Afr Med J ; 45(Suppl 2): 8, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38370098

RESUMEN

The Nigeria Polio Emergency Operations Centre (EOC) was established in October 2012 to strengthen coordination, provide strategic direction based on real-time data analysis, and manage all operational aspects of the polio eradication program. The establishment of seven state-level polio EOCs followed. With success achieved in the interruption of wild poliovirus (WPV) transmission as certified in 2020, the future direction of the polio EOC is under consideration. This paper describes the role of the polio EOC in other emergencies and perspectives on future disease control initiatives. A description of the functionality and operations of the polio EOC and a review of documentation of non-polio activities supported by the EOC was done. Key informant insights of national and state-level stakeholders were collected through an electronic questionnaire to determine their perspectives on the polio EOC's contributions and its future role in other public health interventions. The polio EOC structure is based on an incident management system with clear terms of reference and accountability and with full partner coordination. A decline in WPV1 cases was observed from 122 cases in 2012 to 0 in 2015; previously undetected transmission of WPV1 was confirmed in 2016 and all transmission was interrupted under the coordination of the EOCs at national and state levels. During 2014-2019, the polio EOC infrastructure and staff expertise were used to investigate and respond to outbreaks of Ebola, measles, yellow fever, and meningitis and to oversee maternal and neonatal tetanus elimination campaigns. The EOC structure at the national and state levels has contributed to the positive achievements in the polio eradication program in Nigeria and further in the coordination of other disease control and emergency response activities. The transition of the polio EOCs and their capacities to support other non-polio programs will contribute to harnessing the country's capacity for effective coordination of public health initiatives and disease outbreaks.


Asunto(s)
Poliomielitis , Poliovirus , Recién Nacido , Humanos , Nigeria/epidemiología , Programas de Inmunización , Vigilancia de la Población , Poliomielitis/epidemiología , Poliomielitis/prevención & control , Brotes de Enfermedades/prevención & control , Erradicación de la Enfermedad
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