JOINT ESTIMATION OF THE TRANSMISSIBILITY AND SEVERITY OF EBOLA VIRUS DISEASE IN REAL TIME

2017 ◽  
Vol 25 (04) ◽  
pp. 587-603 ◽  
Author(s):  
YUSUKE ASAI ◽  
HIROSHI NISHIURA
Keyword(s):  
Real Time ◽  
Ebola Virus ◽  
Virus Disease ◽  
Critical Role ◽  
Estimation Method ◽  
Case Fatality ◽  
Ascertainment Bias ◽  
Joint Estimation ◽  
Ebola Virus Disease ◽  
Strong Impact

The effective reproduction number [Formula: see text], the average number of secondary cases that are generated by a single primary case at calendar time [Formula: see text], plays a critical role in interpreting the temporal transmission dynamics of an infectious disease epidemic, while the case fatality risk (CFR) is an indispensable measure of the severity of disease. In many instances, [Formula: see text] is estimated using the reported number of cases (i.e., the incidence data), but such report often does not arrive on time, and moreover, the rate of diagnosis could change as a function of time, especially if we handle diseases that involve substantial number of asymptomatic and mild infections and large outbreaks that go beyond the local capacity of reporting. In addition, CFR is well known to be prone to ascertainment bias, often erroneously overestimated. In this paper, we propose a joint estimation method of [Formula: see text] and CFR of Ebola virus disease (EVD), analyzing the early epidemic data of EVD from March to October 2014 and addressing the ascertainment bias in real time. To assess the reliability of the proposed method, coverage probabilities were computed. When ascertainment effort plays a role in interpreting the epidemiological dynamics, it is useful to analyze not only reported (confirmed or suspected) cases, but also the temporal distribution of deceased individuals to avoid any strong impact of time dependent changes in diagnosis and reporting.

scholarly journals Use of Viremia to Evaluate the Baseline Case Fatality Ratio of Ebola Virus Disease and Inform Treatment Studies: A Retrospective Cohort Study

PLoS Medicine ◽  
2015 ◽  
Vol 12 (12) ◽  
pp. e1001908 ◽  
Author(s):  
Oumar Faye ◽  
Alessio Andronico ◽  
Ousmane Faye ◽  
Henrik Salje ◽  
Pierre-Yves Boëlle ◽  
...  
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Ebola Virus ◽  
Virus Disease ◽  
Case Fatality ◽  
Ebola Virus Disease ◽  
Case Fatality Ratio ◽  
Baseline Case

scholarly journals Effects of vaccines in protecting against Ebola virus disease: protocol for a systematic review

BMJ Open ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. e029617 ◽  
Author(s):  
Lindi Mathebula ◽  
Duduzile Edith Ndwandwe ◽  
Elizabeth Pienaar ◽  
Charles Shey Wiysonge
Keyword(s):  
Systematic Review ◽  
Ebola Virus ◽  
Virus Disease ◽  
Data Extraction ◽  
Case Fatality ◽  
Fixed Effect Model ◽  
Ebola Virus Disease ◽  
Pool Data ◽  
Cochrane Central Register ◽  
Clinical Trial Registry

IntroductionEbola virus disease is one of the most devastating infectious diseases in the world with up to 90% case fatality observed. There are at least 13 candidate vaccines developed and being tested to prevent the occurrence of the Ebola virus disease. While none of these candidate vaccines has received regulatory approval for use, one candidate vaccine (rVSVΔG-ZEBOV-GP) has been granted access for emergency use. Two other candidate vaccines (GamEvac-Combi and Ad5-EBOV) have been licensed for emergency use in their countries of origin. The objective of this systematic review is to summarise the effects of the Ebola candidate vaccines in humans.Methods and analysisWe will search for potentially eligible studies, with no language or date restrictions, in the Cochrane Central Register of Controlled Trials, PubMed, Scopus, the WHO International Clinical Trial Registry Platform, and reference lists of relevant publications. The Cochrane Database of Systematic Reviews (CDSR) and the Database of Abstracts of Reviews of Effect (DARE) will be searched for related reviews. Two review authors will independently screen search records, assess study eligibility, perform data extraction, and assess the risk of bias; and reconcile their findings. We will pool data from similar studies using Mantel-Haenszel’s fixed-effect model.Ethics and disseminationThis study is exempted from ethical consideration since the data collected are publicly available and at no point will confidential information from human participants be used. We will disseminate our results through publications in peer-reviewed journals and relevant conferences.PROSPERO registration numberCRD42018110505.

The Epidemiological Presentation Pattern of Ebola Virus Disease Outbreaks: Changes from 1976 to 2019

2020 ◽  
Vol 35 (3) ◽  
pp. 247-253
Author(s):  
Pedro Arcos González ◽  
Ángel Fernández Camporro ◽  
Anneli Eriksson ◽  
Carmen Alonso Llada
Keyword(s):  
At Risk ◽  
Ebola Virus ◽  
Virus Disease ◽  
Disease Outbreaks ◽  
Case Fatality ◽  
Ebola Virus Disease ◽  
World Health ◽  
Study Objective ◽  
Population At Risk ◽  
Case Fatality Ratio

AbstractIntroduction:Ebola Virus Disease (EVD) is the international health emergency paradigm due to its epidemiological presentation pattern, impact on public health, resources necessary for its control, and need for a national and international response.Study Objective:The objective of this work is to study the evolution and progression of the epidemiological presentation profile of Ebola disease outbreaks since its discovery in 1976 to the present, and to explore the possible reasons for this evolution from different perspectives.Methods:Retrospective observational study of 38 outbreaks of Ebola disease occurred from 1976 through 2019, excluding laboratory accidents. United Nations agencies and programs; Ministries of Health; the US Centers for Disease Control and Prevention (CDC); ReliefWeb; emergency nongovernmental organizations; and publications indexed in PubMed, EmBase, and Clinical Key have been used as sources of data. Information on the year of the outbreak, date of beginning and end, duration of the outbreak in days, number of cases, number of deaths, population at risk, geographic extension affected in Km2, and time of notification of the first cases to the World Health Organization (WHO) have been searched and analyzed.Results:Populations at risk have increased (P = .024) and the geographical extent of Ebola outbreaks has grown (P = .004). Reporting time of the first cases of Ebola to WHO has been reduced (P = .017) and case fatality (P = .028) has gone from 88% to 62% in the period studied. There have been differences (P = .04) between the outbreaks produced by the Sudan and Zaire strains of the virus, both in terms of duration and case fatality ratio (Sudan strain 74.5 days on average and 62.7% of case fatality ratio versus Zaire strain with 150 days on average and 55.4% case fatality ratio).Conclusion:There has been a change in the epidemiological profile of the Ebola outbreaks from 1976 through 2019 with an increase in the geographical extent of the outbreaks and the population at risk, as well as a significant decrease in the outbreaks case fatality rate. There have been advances in the detection and management capacity of outbreaks, and the notification time to the WHO has been reduced. However, there are social, economic, cultural, and political obstacles that continue to greatly hinder a more efficient epidemiological approach to Ebola disease, mainly in Central Africa.

scholarly journals Ebola virus disease diagnosis by real-time RT-PCR: A comparative study of 11 different procedures

2016 ◽  
Vol 77 ◽  
pp. 9-14 ◽  
Author(s):  
Pascal Cherpillod ◽  
Manuel Schibler ◽  
Gaël Vieille ◽  
Samuel Cordey ◽  
Aline Mamin ◽  
...  
Keyword(s):  
Comparative Study ◽  
Real Time ◽  
Ebola Virus ◽  
Virus Disease ◽  
Disease Diagnosis ◽  
Ebola Virus Disease ◽  
Rt Pcr

scholarly journals Ocular Manifestations of Ebola Virus Disease: An Ophthalmologist’s Guide to Prevent Infection and Panic

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Enzo Maria Vingolo ◽  
Giuseppe Alessio Messano ◽  
Serena Fragiotta ◽  
Leopoldo Spadea ◽  
Stefano Petti
Keyword(s):  
Ebola Virus ◽  
Virus Disease ◽  
Clinical Signs ◽  
Case Fatality ◽  
Hemorrhagic Fever ◽  
Ebola Virus Disease ◽  
Ocular Manifestations ◽  
Ebola Hemorrhagic Fever ◽  
Sub Saharan ◽  
The Moment

Ebola virus disease (EVD—formerly known as Ebola hemorrhagic fever) is a severe hemorrhagic fever caused by lipid-enveloped, nonsegmented, negative-stranded RNA viruses belonging to the genusEbolavirus. Case fatality rates may reach up to 76% of infected individuals, making this infection a deadly health problem in the sub-Saharan population. At the moment, there are still no indications on ophthalmological clinical signs and security suggestions for healthcare professionals (doctors and nurses or cooperative persons). This paper provides a short but complete guide to reduce infection risks.

scholarly journals Emergence of Ebola Virus Disease (EVD): Key Facts

2015 ◽  
Vol 6 (1) ◽  
pp. 35-37
Author(s):  
Md Mahfuzar Rahman ◽  
Farnaz Mehrin ◽  
Fahim Ahmed
Keyword(s):  
Ebola Virus ◽  
Virus Disease ◽  
Virus Transmission ◽  
Specific Treatment ◽  
Case Fatality ◽  
Signs And Symptoms ◽  
Hemorrhagic Fever ◽  
Ebola Virus Disease ◽  
Background Information ◽  
Global Threat

The modern emerging infection Ebola Virus Disease (EVD) is of global threat originates from Africa region. This is zoonotic and identified as human diseases or previously called Ebola hemorrhagic fever which is a highly fatal human illness where case fatality rate is found up to 90%. The virus transmission begins from wild animals to human and then spreads within population through human to human. Fruit bats are found as natural host of Ebola virus. There is no specific treatment or vaccine available in the market so far, intensive supportive care is needed for severely ill patients. This paper highlights background information, problem statement, viral characteristics, mode of transmission, signs and symptoms, prevention & vaccination. It also indicates possible actions towards prevention of transmission & personal protection.Anwer Khan Modern Medical College Journal Vol. 6, No. 1: January 2015, Pages 35-37

scholarly journals Recurrent outbreaks of Ebola Virus Disease in Africa: A Meta-analysis of case fatality rates

2020 ◽  
Author(s):  
Joseph Kawuki ◽  
Taha Hussein Musa ◽  
Xiaojin Yu
Keyword(s):  
Ebola Virus ◽  
Assessment Tool ◽  
Virus Disease ◽  
Control Strategies ◽  
Meta Analysis ◽  
Case Fatality ◽  
Ebola Virus Disease ◽  
Surveillance Systems ◽  
Potential Factors ◽  
English Articles

Abstract Background: In the last decade, Africa has witnessed several outbreaks of Ebola virus disease (EVD), each presenting with varying case fatality rate (CFR) and other socio-economic impacts. This study aims to summarise the CFR and identify potential factors that influenced the severity of EVD outbreaks in Africa.Methods: This was a systematic review and meta-analysis of EVD outbreaks published between January 2010 and March 2020, using Web of Science, Scopus and PubMed databases. Only English articles and reports, including the number of cases and deaths during the outbreak in Africa, were considered. Quality of the included articles was assessed using the Murad’s quality assessment tool. The analysis was conducted using Stata (version 12), pooled effect sizes were calculated using the random-effects model and heterogeneity was tested for using the I2 statistic.Result: Thirteen studies with 32,300 cases and 13,727 deaths were identified whose pooled CFR was 60% (95% CI: 47-73%). The most EVD-affected countries were DRC with 5 outbreaks and a pooled CFR of 65% (95% CI: 59-71%), followed by Uganda with 3 outbreaks and CFR= 83% (95% CI: 60-99%). Zaire ebolavirus caused the most outbreaks (10), with a CFR= 58% (95% CI: 45-71%). Besides, outbreaks with less than 1000 cases reported a higher CFR rate compared to those with more cases.Conclusion: The study has revealed a considerably high CFR caused by the recurrent EVD outbreaks in Africa. It also notes an implementation gap of the prevention and control strategies, and thus identifies a need to strengthen the surveillance systems and response mechanisms to enable early detection and prompt control of future outbreaks.

scholarly journals Laboratory Findings, Compassionate Use of Favipiravir, and Outcome in Patients With Ebola Virus Disease, Guinea, 2015—A Retrospective Observational Study

2019 ◽  
Vol 220 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Romy Kerber ◽  
Eva Lorenz ◽  
Sophie Duraffour ◽  
Daouda Sissoko ◽  
Martin Rudolf ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Survival Time ◽  
Ebola Virus ◽  
Virus Disease ◽  
Univariate Analysis ◽  
Case Fatality ◽  
Blood Chemistry ◽  
Ebola Virus Disease ◽  
Treatment Center ◽  
Compassionate Use

Abstract Background In 2015, the laboratory at the Ebola treatment center in Coyah, Guinea, confirmed Ebola virus disease (EVD) in 286 patients. The cycle threshold (Ct) of an Ebola virus–specific reverse transcription–polymerase chain reaction assay and 13 blood chemistry parameters were measured on admission and during hospitalization. Favipiravir treatment was offered to patients with EVD on a compassionate-use basis. Methods To reduce biases in the raw field data, we carefully selected 163 of 286 patients with EVD for a retrospective study to assess associations between potential risk factors, alterations in blood chemistry findings, favipiravir treatment, and outcome. Results The case-fatality rate in favipiravir-treated patients was lower than in untreated patients (42.5% [31 of 73] vs 57.8% [52 of 90]; P = .053 by univariate analysis). In multivariate regression analysis, a higher Ct and a younger age were associated with survival (P < .001), while favipiravir treatment showed no statistically significant effect (P = .11). However, Kaplan-Meier analysis indicated a longer survival time in the favipiravir-treated group (P = .015). The study also showed characteristic changes in blood chemistry findings in patients who died, compared with survivors. Conclusions Consistent with the JIKI trial, this retrospective study revealed a trend toward improved survival in favipiravir- treated patients; however, the effect of treatment was not statistically significant, except for its influence on survival time.

scholarly journals Influence of Referral Pathway on Ebola Virus Disease Case-Fatality Rate and Effect of Survival Selection Bias

2017 ◽  
Vol 23 (4) ◽  
pp. 597-600 ◽  
Author(s):  
Frauke Rudolf ◽  
Mads Damkjær ◽  
Suzanne Lunding ◽  
Kenn Dornonville de la Cour ◽  
Alyssa Young ◽  
...  
Keyword(s):  
Selection Bias ◽  
Case Fatality Rate ◽  
Ebola Virus ◽  
Virus Disease ◽  
Case Fatality ◽  
Ebola Virus Disease ◽  
Fatality Rate ◽  
Survival Selection ◽  
Disease Case

scholarly journals The impact of malaria coinfection on Ebola virus disease outcomes: A systematic review and meta-analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251101
Author(s):  
Hannah M. Edwards ◽  
Helen Counihan ◽  
Craig Bonnington ◽  
Jane Achan ◽  
Prudence Hamade ◽  
...  
Keyword(s):  
Systematic Review ◽  
Ebola Virus ◽  
Virus Disease ◽  
Meta Analysis ◽  
Case Fatality ◽  
The Body ◽  
Diagnostic Methods ◽  
Ebola Virus Disease ◽  
Significant Difference ◽  
The Impact

Introduction Viral outbreaks present a particular challenge in countries in Africa where there is already a high incidence of other infectious diseases, including malaria which can alter immune responses to secondary infection. Ebola virus disease (EVD) is one such problem; understanding how Plasmodium spp. and Ebolavirus (EBOV) interact is important for future outbreaks. Methods We conducted a systematic review in PubMed and Web of Science to find peer-reviewed papers with primary data literature to determine 1) prevalence of EBOV/Plasmodium spp. coinfection, 2) effect of EBOV/Plasmodium spp. coinfection on EVD pathology and the immune response, 3) impact of EBOV/Plasmodium spp. coinfection on the outcome of EVD-related mortality. Random effects meta-analyses were conducted with the R package meta to produce overall proportion and effect estimates as well as measure between-study heterogeneity. Results From 322 peer-reviewed papers, 17 were included in the qualitative review and nine were included in a meta-analysis. Prevalence of coinfection was between 19% and 72%. One study reported significantly lower coagulatory response biomarkers in coinfected cases but no difference in inflammatory markers. Case fatality rates were similar between EBOV(+)/Pl(+) and EBOV(+)/Pl(-) cases (62.8%, 95% CI 49.3–74.6 and 56.7%, 95% CI 53.2–60.1, respectively), and there was no significant difference in risk of mortality (RR 1.09, 95% CI 0.90–1.31) although heterogeneity between studies was high. One in vivo mouse model laboratory study found no difference in mortality by infection status, but another found prior acute Plasmodium yoeli infection was protective against morbidity and mortality via the IFN-γ signalling pathway. Conclusion The literature was inconclusive; studies varied widely and there was little attempt to adjust for confounding variables. Laboratory studies may present the best option to answer how pathogens interact within the body but improvement in data collection and analysis and in diagnostic methods would aid patient studies in the future.

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