scholarly journals Spatial spread of the West Africa Ebola epidemic

2016 ◽  
Vol 3 (8) ◽  
pp. 160294 ◽  
Author(s):  
Andrew M. Kramer ◽  
J. Tomlin Pulliam ◽  
Laura W. Alexander ◽  
Andrew W. Park ◽  
Pejman Rohani ◽  
...  
Keyword(s):  
West Africa ◽  
Sierra Leone ◽  
Ebola Virus ◽  
Emerging Diseases ◽  
Relative Probability ◽  
Effective Response ◽  
Spatial Spread ◽  
Force Of Infection ◽  
International Border

Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013–2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia and Sierra Leone and neighbouring countries. This model out-performed alternative models based on diffusive spread, the force of infection, mobility estimated from cell phone records and other hypothesized patterns of spread. These findings highlight the importance of integrated geography to epidemic expansion and may contribute to identifying both the most vulnerable unaffected areas and locations of maximum intervention value.

scholarly journals Seroprevalence of Ebola virus infection in Bombali District, Sierra Leone

2017 ◽  
Author(s):  
Nadege Goumkwa Mafopa ◽  
Gianluca Russo ◽  
Raoul Emeric Guetiya Wadoum ◽  
Emmanuel Iwerima ◽  
Vincent Batwala ◽  
...  
Keyword(s):  
Immune Response ◽  
Virus Infection ◽  
West Africa ◽  
Sierra Leone ◽  
Ebola Virus ◽  
Virus Disease ◽  
Asymptomatic Infection ◽  
Ebola Virus Disease ◽  
Efficient Immune Response ◽  
Ebola Virus Infection

A serosurvey of anti-Ebola Zaire virus nucleoprotein IgG prevalence was carried out among Ebola virus disease survivors and their Community Contacts in Bombali District, Sierra Leone. Our data suggest that the specie of Ebola virus (Zaire) responsible of the 2013-2016 epidemic in West Africa may cause mild or asymptomatic infection in a proportion of cases, possibly due to an efficient immune response.

English in West Africa

2015 ◽  
Author(s):  
Ulrike Gut
Keyword(s):  
West Africa ◽  
Sierra Leone ◽  
Structural Properties ◽  
West African ◽  
The Other ◽  
African Countries ◽  
The West ◽  
Current Role ◽  
British Colonization

This chapter describes the history, role, and structural properties of English in the West African countries the Gambia, Sierra Leone, Liberia, Ghana, Nigeria, the anglophone part of Cameroon, and the island of Saint Helena. It provides an overview of the historical phases of trading contact, British colonization and missionary activities and describes the current role of English in these multilingual countries. Further, it outlines the commonalities and differences in the vocabulary, phonology, morphology, and syntax of the varieties of English spoken in anglophone West Africa. It shows that Liberian Settler English and Saint Helenian English have distinct phonological and morphosyntactic features compared to the other West African Englishes. While some phonological areal features shared by several West African Englishes can be identified, an areal profile does not seem to exist on the level of morphosyntax.

scholarly journals Tactics and Strategies for Managing Ebola Outbreaks and the Salience of Immunization

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Wayne M. Getz ◽  
Jean-Paul Gonzalez ◽  
Richard Salter ◽  
James Bangura ◽  
Colin Carlson ◽  
...  
Keyword(s):  
West Africa ◽  
Simulation Model ◽  
Sierra Leone ◽  
Ebola Virus ◽  
Viral Disease ◽  
Current Generation ◽  
Vaccination Programs ◽  
Contact Rates ◽  
Transmission Chain ◽  
Educational Campaigns

We present a stochastic transmission chain simulation model for Ebola viral disease (EVD) in West Africa, with the salutary result that the virus may be more controllable than previously suspected. The ongoing tactics to detect cases as rapidly as possible and isolate individuals as safely as practicable is essential to saving lives in the current outbreaks in Guinea, Liberia, and Sierra Leone. Equally important are educational campaigns that reduce contact rates between susceptible and infectious individuals in the community once an outbreak occurs. However, due to the relatively low R0 of Ebola (around 1.5 to 2.5 next generation cases are produced per current generation case in naïve populations), rapid isolation of infectious individuals proves to be highly efficacious in containing outbreaks in new areas, while vaccination programs, even with low efficacy vaccines, can be decisive in curbing future outbreaks in areas where the Ebola virus is maintained in reservoir populations.

scholarly journals Dynamics of Ebola epidemics in West Africa 2014

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 319 ◽  
Author(s):  
Robin J. Evans ◽  
Musa Mammadov
Keyword(s):  
West Africa ◽  
Sierra Leone ◽  
Ebola Virus ◽  
Virus Transmission ◽  
Infectious Period ◽  
Time Intervals ◽  
Total Period ◽  
Reproduction Numbers ◽  
Major Parameter ◽  
Total Data

This paper investigates the dynamics of Ebola virus transmission in West Africa during 2014. The reproduction numbers for the total period of epidemic and for different consequent time intervals are estimated based on a simple linear model. It contains one major parameter - the average infectious period that defines the dynamics of epidemics.Numerical implementations are carried out on data collected from three countries Guinea, Sierra Leone and Liberia as well as the total data collected worldwide. Predictions are provided by considering different scenarios involving the average times of infectiousness for the next few months and the end of the current epidemic is estimated according to each scenario.

scholarly journals Descriptive analyses and risk of death due to Ebola Virus Disease, West Africa, 2014

2015 ◽  
Vol 9 (12) ◽  
pp. 1298-1307 ◽  
Author(s):  
Folorunso Oludayo Fasina ◽  
Olubukola T. Adenubi ◽  
Samuel T. Ogundare ◽  
Aminu Shittu ◽  
Dauda G. Bwala ◽  
...  
Keyword(s):  
West Africa ◽  
Sierra Leone ◽  
Healthcare Workers ◽  
Ebola Virus ◽  
Virus Disease ◽  
Healthcare Delivery ◽  
Ebola Virus Disease ◽  
World Health ◽  
Public Healthcare ◽  
Risk Of Death

Introduction: Since the first case of Ebola virus disease (EVD) in Guinea in 2013, major outbreaks have been reported in West Africa. Methodology: Cases and fatalities of EVD caused by Zaire Ebola virus (ZEBOV) were evaluated, and the risks of dying in the general population and in healthcare workers were assessed. Results: The case fatality rate estimated for EVD was 76.4% in 20 studies. Cumulative proportion of fatal cases in West Africa was 42.9%, 30.1%, and 64.2% in Liberia, Sierra Leone, and Guinea, respectively. The proportion of total deaths in Liberia, Sierra Leone, and Guinea was 42.5%, 35.8%, and 21.6%, respectively. Healthcare workers were at higher risk of dying compared with the general public, and the same applied to intense transmission countries and to countries with sufficient bed capacities. The declaration of a health emergency “out-of-control” situation by the World Health Organization on 8 August 2014 reduced the risk of death among patients. Factors including deplorable healthcare delivery infrastructure in war-ravaged regions of Africa, the impotence of governments to enforce public health regulations, and the loss of confidence in public healthcare delivery programs were key among others factors that enhanced the spread and magnitude of outbreaks. Conclusions: The findings underscore the need for an overall re-appraisal of the healthcare systems in African countries and the ability to cope with widespread epidemic challenges. Outbreaks like that of Ebola diseases should be handled not just as a medical emergency but also a socio-economic problem with significant negative economic impacts.

Abolition on shore

2019 ◽  
pp. 41-68
Author(s):  
Mary Wills
Keyword(s):  
Nineteenth Century ◽  
West Africa ◽  
Sierra Leone ◽  
Slave Trade ◽  
West African ◽  
Early Nineteenth Century ◽  
Naval Officers

Naval officers played a part in a reconfiguration of relations between Britain and West Africa in the early nineteenth century, as British abolitionist ideals and policies were introduced in the colony of Sierra Leone and increasingly rolled out along the coast. This chapter details the role of naval officers in the pursuit of anti-slavery treaties with African rulers, the encouragement of ‘legitimate’ trade (as non-slave-based trade was termed) and assisting increased exploration and missionary efforts. All were tied to the desire to end the slave trade at source in West African societies via the spread of European ideas of ‘civilization’ among African peoples. Officers’ narratives are revealing of increasing British intervention in West Africa, and how economic and strategic advantages for Britain became inextricable from humanitarian incentives.

Ebola Epidemic in Sierra Leone: on the Crisis Story of the Pre-COVID Era

Istoriya ◽  
2021 ◽  
Vol 12 (6 (104)) ◽  
pp. 0
Author(s):  
Dmitriy Mikhel
Keyword(s):  
West Africa ◽  
Sierra Leone ◽  
Ebola Virus ◽  
African Countries ◽  
Humanitarian Organizations ◽  
System A ◽  
The People ◽  
State Administration ◽  
History Of ◽  
Health Institutions

This article examines the history of one of the most significant crises that occurred shortly before the current global crisis caused by the COVID-19 pandemic. The Ebola outbreak in West Africa, which lasted from February 2014 to December 2015, killed more than 11,000 people and sowed panic around the world. What started as a local phenomenon quickly became a major challenge to national health in West African countries such as Sierra Leone, Liberia, Guinea, etc., as well as to global health institutions such as WHO and international humanitarian organizations. The most severe consequences of Ebola were felt in Sierra Leone — a country rich in natural resources, but with a poor state administration system and a dilapidated health care system. A complex set of factors — environmental, economic, political, social and cultural — was responsible for the spread of the Ebola virus among the people of West Africa. All of them are now more or less well understood, although a holistic picture of the events of the 2014—2015 Ebola epidemic in West Africa remains unclear. The aim of this article is to reconstruct the general history of the Ebola epidemic in Sierra Leone, as well as to characterize its causes and consequences.

scholarly journals Introduction of Ebola virus into a remote border district of Sierra Leone, 2014: use of field epidemiology and RNA sequencing to describe chains of transmission

2019 ◽  
Vol 147 ◽  
Author(s):  
M. B. DeSilva ◽  
T. Styles ◽  
C. Basler ◽  
F. L. Moses ◽  
F. Husain ◽  
...  
Keyword(s):  
Public Health ◽  
West Africa ◽  
Sierra Leone ◽  
Genome Sequencing ◽  
Ebola Virus ◽  
Virus Disease ◽  
Whole Genome ◽  
Geographic Isolation ◽  
Source Of Infection ◽  
Field Response

AbstractIn early October 2014, 7 months after the 2014–2015 Ebola epidemic in West Africa began, a cluster of reported deaths in Koinadugu, a remote district of Sierra Leone, was the first evidence of Ebola virus disease (Ebola) in the district. Prior to this event, geographic isolation was thought to have prevented the introduction of Ebola to this area. We describe our initial investigation of this cluster of deaths and subsequent public health actions after Ebola was confirmed, and present challenges to our investigation and methods of overcoming them. We present a transmission tree and results of whole genome sequencing of selected isolates to identify the source of infection in Koinadugu and demonstrate transmission between its villages. Koinadugu's experience highlights the danger of assuming that remote location and geographic isolation can prevent the spread of Ebola, but also demonstrates how deployment of rapid field response teams can help limit spread once Ebola is detected.

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