As of march 2016, a total of 28 639 evd cases and 11 316 deaths have been reported in 10 countries. A significant unanswered question has arisen for the scientific and engineering communities, as well as the general public, surrounding ebola virus persistence in the environment and the. There are five ebola subspecies, four of which are known to cause the disease. Aug 23, 2018 please use one of the following formats to cite this article in your essay, paper or report. Ebola virus then spreads from person to person through direct contact with blood or body fluids of a person who is sick with or has died from ebola virus disease. Vomiting, diarrhoea and rash usually follow, along with decreased function of the liver and kidneys. We describe the epidemiology of evd cases reported in guineas capital, conakry, and 4 surrounding prefectures coyah, dubreka, forecariah, and kindia, encompassing a full year of the epidemic. We are a research group at the kemriwellcome trust research programme. Ebola virus, a rna virus, was discovered in 1976 as zaire ebolavirus and currently is responsible for outbreak in the west africa. Incidence, transmission, distribution, and control of diseases in a population. Ebola haemorrhagic fever ehf is a febrile haemorrhagic illness of which there are four distinct subtypes. Introduction since 1947, zika virus has been identified sporadically in humans in africa and asia. Ebola virus is the cause of a viral hemorrhagic fever disease. Phe publications gateway number 2015463 pdf, 952kb, 7 pages this file.
Some viruses have a third component, called the virus envelope or outer membrane. The most common species of ebola virus responsible for outbreaks is the zaire ebolavirus, the second most common species being the sudan ebolavirus. Effective control of virus diseases of musa in africa needs to be based on an understanding of the biology and epidemiology of the viruses. Ebola virus disease evd is a lifethreatening viral disease with a fatality rate ranging from around 30% to 90%. Based on a nearcomplete sequence sample of cases, they reconstruct the seeding event and the subsequent rapid expansion of the epidemic in sierra leone in may and june 2014. The viruses that cause evd are located mainly in subsaharan africa. The clinical manifestations, diagnosis, treatment, and prevention of ebola virus disease are discussed elsewhere. Current outbreak is the largest in the history, since discovery of. May 26, 2015 the unprecedented scale of the ebola outbreak in west africa has, as of 29 april 2015, resulted in more than 10,884 deaths among 26,277 cases. In march 2014, an outbreak of evd was recognized in guinea which would become the most significant outbreak of haemorrhagic fever in africa to date. Epidemiology of ebolavirus disease evd and occupational.
Effective control of virus diseases of musa in africa needs to be based on an understanding of the biology and epidemiology of the viruses involved, and on the availability of reliable methods of virus indexing. Person to person ritual washing of ebola victims at funerals nosocomial transmission transmission from animals 4. Here, we propose a hypothesis of the evolutionary history of ebola virus which will be helpful. Siegert, springerverlag, heidelberg new york, 161165.
Since the first report of evd in march 2014, the number of cases has increased rapidly, with the fatality rate of 50%. Epidemiological and evolutionary analysis of the 2014. The evd epidemiology, pathogenesis, and clinical characterization will be discussed in this study. This can happen when a person touches the infected body fluids or objects that are contaminated with them, such as medical equipment like needles and syringes. In 2014, ebola virus disease evd in west africa was first reported during march in 3 southeastern prefectures in guinea. Introduction current outbreak of ebola virus ebov in west africa can be described as most severe public health emergency in modern times 1. Jan 06, 2015 dr darina oflanagan, director, hse health protection surveillance centre presents epidemiology of ebola virus disease at the mater hospital ebola conference in dublin, ireland 121114. Ebola virus disease evd, one of the deadliest viral diseases, was discovered in 1976 when two consecutive outbreaks of fatal hemorrhagic fever occurred in different parts of central africa. Pdf ebola virus epidemiology and evolution in nigeria. The 2014 outbreak of ebola virus ebov disease evd in nigeria was one branch of the major west african epidemic that spanned 202016.
This paper analyses the transmission dynamics of ebola virus disease using the modified seir model which is a system of ordinary differential equation. Epidemiology and prevention of hepatitis b virus infection. The western african ebola virus epidemic 202016 was the most widespread outbreak of ebola virus disease evd in historycausing major loss of life and socioeconomic disruption in the region, mainly in guinea, liberia and sierra leone. Mar 03, 2020 ebola virus is one of at least 30 known viruses capable of causing viral hemorrhagic fever syndrome.
Although there were cases introduced into other continents, africa is the endemic. The exact source of ebola infections remains an open question, and. The ebov first attacks macrophages and dendritic immune cells. When an epidemic occurs, health care workers hcw are at great risk of infection when caring for evd patients. Limited ebola virus exchange across the sierra leonean border. Estimates of the basic reproduction number r 0 for sierra leone vary between 1. The first evd outbreak was reported in the 1970s in zaire now the democratic. Ebola virus, first identified in humans in 1976 during outbreaks in zaire and sudan, is native to subsaharan africa. Mar 10, 2015 the outbreak of ebola virus disease evd continues to spread through west africa. Considering 6 decades have passed since the first identification of the virus, it is perhaps unexpected that zika virus was recognised only recently as capable of causing. Chikv was first recognized as a human pathogen after it was isolated from the serum of an infected patient during an outbreak of debilitating arthritic. Although agents that cause viral hemorrhagic fever syndrome constitute a geographically diverse group of viruses, all of those identified to date are rna viruses with a lipid envelope, all are considered zoonoses, all damage the microvasculature resulting in. Dr darina oflanagan, director, hse health protection surveillance centre presents epidemiology of ebola virus disease at the mater hospital ebola conference in dublin, ireland 121114.
In march 2014, an outbreak of ebola virus ebola arose in western africa. The outbreak started in guinea and rapidly spread to liberia and sierra leone, claiming thousands of lives. Epidemiology of ebolavirus disease evd and occupational evd. Ebola virus disease pathogenesis, clinical presentation and management abstract. Epidemiology of zika virus, 19472007 bmj global health. Common clinical features sudden onset of fever, malaise, myalgia, diarrhoea, hypotension and shock. Ebola virus epidemiology, transmission, and evolution. The 201819 ebola epidemic the democratic republic of the. Ebola virus epidemiology and evolution in nigeria article pdf available in the journal of infectious diseases 214suppl 3. The first cases were recorded in guinea in december 20. The unprecedented scale of the ebola outbreak in west africa has, as of 29 april 2015, resulted in more than 10,884 deaths among 26,277 cases.
Pdf ebola virus epidemiology, diagnosis and control. The outbreak, first declared in march 2014 in guinea and traced back to the end of 20 baize et al. Symptoms may appear anywhere from 2 to 21 days after exposure to ebola virus, though 810 day. The virus envelope is composed of viral lipids and proteins and is easily damaged by heat, disinfectants and detergents. Ebola hemorrhagic fever is considered a classic zoonotic disease with persistence of the ebola virus in a reservoir species. The outbreak of ebola virus disease evd continues to spread through west africa. The most prevalent ebola virus belongs to the species of zaire ebolavirus, with a fatality rate as high as 90%. Ebov is one of the most virulent pathogens among the viral haemorrhagic fevers, and case fatality rates up to 90% have been reported. History of ebola virus disease error processing ssi file. The scientists at work series is intended to provide insights into the daily work of scientists that builds toward discoveries.
Folarin oa1, ehichioya d1, schaffner sf2, winnicki sm2, wohl s2, eromon p1, west kl3, gladdenyoung a3, oyejide ne4, matranga cb3, deme ab5, james a6, tomkinstinch c3, onyewurunwa k1, ladner jt7, palacios g7, nosamiefan i3. The number of potential cases ranges from thousands to millions with mortality rate up to 74% 2. The first presumed fatality was in guinea in december 20, and the first cases in sierra leone were detected in may 2014. Chikungunya virus chikv is a mosquitoborne virus responsible for periodic and explosive outbreaks of a febrile disease that is characterized by severe and sometimes prolonged polyarthritis. Variable patients controls dogs 87% 76% cats 64% 62% rats 80% 77% chickens 78% 73% bats 19% 19%. Epidemiology of epidemic ebola virus disease in conakry. The epidemiology and pathogenesis of ebola virus disease will be presented here, including knowledge that emerged during and after the west african epidemic of ebola virus disease. Hepatitis b virus hbv is a serious public health problem worldwide and major cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma hcc. Zaire, sudan and cote divoire cause illness in humans. Monitoring nipah virus in bat populations from the scientists at work series. It was first reported in march 2014, and was the largest outbreak since the virus was first discovered in.
Multiorgan dysfunction occurs in severe forms with a mortality up to 90%. Folarin oa1, ehichioya d1, schaffner sf2, winnicki sm2, wohl s2, eromon p1, west kl3, gladdenyoung a3, oyejide ne4, matranga cb3, deme ab5, james a6, tomkinstinch c3, onyewurunwa k1, ladner jt7, palacios g7, nosamiefan i3, andersen kg8. The disease was first identified in 1976 during two simultaneous outbreaks in subsaharan africa, one in nzara and the other in yambuku, a village near the ebola river, from which the disease takes its name. People can get evd through direct contact with an infected animal bat or nonhuman primate or a sick or dead person infected with ebola virus. Ebola is also known as ebola virus disease evd or ebola hemorrhagic fever ehf. The viruses infecting musa differ in their biology, mode of transmission and epidemiology, and these differences have important practical implications for the control of the diseases caused by these viruses.
Since then, there have been more than 0 cases reported with a mortality rate of approximately 70% in clinically confirmed cases. Mar 10, 2015 ebola virus is the pathogen of evd, which is mainly endemic in west africa. Withdrawn ebola virus disease epidemiological update. Over the past 40 years, sporadic ebola virus disease evd outbreaks have occurred mostly in the central african region. Threat to humans, lessons learnt and preparedness plans an update on its 40 years journey article pdf available march 2017. Epidemiology of epidemic ebola virus disease in conakry and surrounding prefectures, guinea, 20142015 adriana rico, debra brody, fatima coronado, marc rondy, lena fiebig, andrea carcelen, varough m. We conduct intensive long term studies into population dynamics of viral pathogens informing intervention strategies. Ebola virus disease evd, also known as ebola hemorrhagic fever ehf, is a disease of humans and other primates caused by ebola viruses. Studies were initiated in the philippines to identify the source of the virus among monkeybreeding and export facilities, to establish surveillance and testing, and to assess the risk and significance of. Prior to the ongoing outbreak, ebola virus disease. Ebola virus infection epidemiology bmj best practice. Epidemiology of epidemic ebola virus disease in conakry and. Percentage of people in this study who reported the presence of illness among other animals on farm. Ebola subtype reston ebor virus infection was detected in macaques imported into the united states from the philippines in march 1996.
We study the seir model with vaccination to see the effect of vaccination on both the spread and control of the disease. The numerical analysis is done using matlab ode 45 which uses runge kutta method of fourth order. Transmission dynamics and control of ebola virus disease. Agent factors agent ebola virus contain singlestrand, noninfectious rna genomes. Guinea, sierra leone, and liberia have been the most heavily affected.
The first outbreak occurred in the democratic republic of congo formerly zaire in a village near the ebola river, which gave the virus its name. Signs and symptoms typically start between two days and three weeks after contracting the virus with a fever, sore throat, muscular pain, and headaches. It was estimated that approximately 2 billion people have serological evidence of past or present hbv infection. Over the past 40 years, more than 20 outbreaks have occurred in africa, with most of the known outbreaks occurring in the past 20 years. Phe publications gateway number 2015463 pdf, 952kb, 7 pages this file may not be suitable for users of assistive. Ebola virus epidemiology, transmission, and evolution during. Ebola virus ebov belongs to the filoviridae family and is responsible for a severe disease characterized by the sudden onset of fever and malaise accompanied by other nonspecific signs and symptoms. Although there were cases introduced into other continents, africa is the.
Ebola, also known as ebola virus disease evd, is a viral haemorrhagic fever of humans and other primates caused by ebolaviruses. Ebolavirus disease evd is a serious infectious disease in humans caused by a virus whose natural reservoirs are thought to be fruit bats of the pteropodidae family. Other zoonotic viruses, such as hendra and menangle viruses. Ebola virus epidemiology and evolution in nigeria the.
More than 350 million are chronic carriers of hbv 1. Ebola virus is one of the most virulent pathogens known to infect humans. Epidemiology and risk factors for ebola virus disease in. Ebola virus is characterized by high lethality, high infectivity, and lack of effective treatment or prophylaxis.
Ebola is a rare but deadly virus that causes fever, body aches, and diarrhea, and sometimes bleeding inside and outside the body as the virus spreads through the body, it damages the immune. Here, we propose a hypothesis of the evolutionary history of ebola virus which will be helpful to investigate the molecular evolution of these viruses. A previous study of ebov makona sequences elucidated viral transmission and evolution during the early stages of the outbreak in sierra leone gire et al. The zaire ebolavirus was responsible for the outbreak that started in west africa in 2014. Ebola virus disease evd is a rare and deadly disease in people and nonhuman primates. Ebola virus is named after a small river in zaire now the democratic republic of the congo, drc where the first evd outbreak occurred in 1976. The ebola outbreak epidemiology teamoutbreak of ebola virus disease in the democratic republic of the congo, aprilmay, 2018. The west africa ebola virus species zaire ebolavirus outbreak is the largest in history with sustained transmission in multiple countries. Ebola was first identified in 1976 near the ebola river in the country now known as the democratic republic of the congo. Epidemiology of nipah virus student handout infectious disease revised october 2017. Initial transmissions in sierra leone were concentrated. Ebola virus is the pathogen of evd, which is mainly endemic in west africa. Mathematical model of the spread and control of ebola. The 202015 western african ebola virus disease evd epidemic, caused by the ebola virus ebov makona variant kuhn et al.
Ebola ebola virus disease ebola ebola virus disease fact sheet. The mucinliked region of the ebola virus envelope play a significant role in viral infection in nonhuman primates and. In this study will be presented epidemiology and pathogenesis of ebola virus disease including new findings resulting from the studies linked with 2014 ebola outbreak in west africa. The virus causing this outbreak, the zaire ebolavirus ebov, belongs to the genus ebolavirus which together with the genus marburgvirus forms the family of the filoviridae. Ebola virus disease evd in west africa was first reported during early march 2014 in guineas 3 southeastern prefectures gueckedou, macenta, and kissidougou, which border liberia and sierra leone. Transmission dynamics and control of ebola virus disease evd. Epidemiology of nipah virus activity educator materials overview this worksheet complements the short video virus hunter. Ebola virus disease, pathogenesis, clinical presentation, diagnosis, treatment.
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