Evd outbreaks typically start from a single case of probable zoonotic transmission, followed by. The virus obtained its name from the ebola river in africa. Mar 10, 2015 the outbreak of ebola virus disease evd continues to spread through west africa. Assessment of the severity of ebola virus disease in sierra.
Ebola virus disease evd, also known as ebola hemorrhagic fever ehf, is a disease of humans and other primates caused by ebola viruses. The epidemiology, pathogenesis, and clinical manifestations of ebola and marburg virus disease will bepresented here. Epidemiology is the study of the distribution and determinants of health problems in specified. Ebola virus disease evd is a severe and frequently lethal disease caused by ebola virus ebov. Outbreak of ebola virus disease in the democratic republic of.
Epidemiological features and trends of ebola virus disease in. Introduction to ebola virus disease world health organization. Pdf just how ebola actually gets from animals or the environment and into humans is unclear. The ongoing ebola virus outbreak in the democratic republic of the congo has similar epidemiological features to previous ebola virus disease outbreaks. Jul 08, 2016 epidemiology and risk factors for ebola virus disease in sierra leone23 may 2014 to 31 january 2015. Pdf the epidemiology of ebola virus disease researchgate. Aug 23, 2018 ebola hemorrhagic fever is considered a classic zoonotic disease with persistence of the ebola virus in a reservoir species.
Kansas ebola preparedness and response plan version 9. The 201819 ebola epidemic the democratic republic of the. The outbreak of ebola virus disease evd continues to spread through west africa. Limited evidence is available on pediatric disease course and prognosis. Agent factors agent ebola virus contain singlestrand, noninfectious rna genomes. It most commonly affects people and nonhuman primates, such as monkeys, chimpanzees, and gorillas. Epidemiological features and trends of ebola virus disease. Signs and symptoms typically start between two days and three weeks after contracting the virus with a fever, sore throat, muscular pain, and headaches. The virus is a member of the filoviridae family genus ebolavirus. The illness affects humans and nonhuman primates monkeys, gorillas and chimpanzees the. Who ebola response team, aguaagum j, ariyarajah a, et al. The biology of the ebola virus, and the epidemiology and routes of transmission of evd are now well known 1,2.
Epidemiology, pathogenesis, and clinical manifestations of. Ebola virus is transmitted from human to human, primarily through close contact with the body fluids or corpse of an evd patient or contact with contaminated environments. In this article, we present an overview of the pathogen, its epidemiology and transmission, clinical and laboratory manifestations, treatment and infection control procedures, with an emphasis on what is known about ebola virus disease in the pediatric population. Pdf currently, west africa is facing the largest outbreak of ebola virus disease evd in history. The ebola virus disease outbreak in tonkolili district, sierra leone.
The 202015 west african epidemic, by far the most geographically extensive, most fatal, and longest lasting epidemic in ebolas history, presented an enormous international public health challenge, but it also provided insights into ebolas pathogenesis and natural history, clinical expression, treatment, prevention, and control. Ebola hemorrhagic fever is considered a classic zoonotic disease with persistence of the ebola virus in a reservoir species. Ebola virus disease formerly known as ebola hemorrhagic fever is a rare and often. For each outbreak of evd a single introduction from the animal kingdom is needed. Since the first report of evd in march 2014, the number of cases has increased rapidly, with the fatality rate of 50%. No approved therapyis available for the treatment of these diseases, but progress has been made in new experimental approachesto postexposure prophylaxis andor treatment that are effective in laboratory primates 411. 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. Ebola surveillance guinea, liberia, and sierra leone.
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. Ebola virus disease evd is a severe zoonotic disease caused by the ebola virus. The epidemiology, pathogenesis, treatment, and prevention of this disease are discussed elsewhere. The illness affects humans and nonhuman primates monkeys, gorillas and chimpanzees the disease was first identified in 1976 in two. In comparison with earlier ebola outbreaks mortality have been higher 80 90 percent, but number of cases was a thousand times lower. Patients with severe forms of the disease may develop hemorrhagic symptoms and multiorgan. Cdc laboratories produce first genomic sequence of liberian ebola. Ebola subtype reston ebor virus infection was detected in macaques imported into the united states from the philippines in march 1996. Epidemiology and risk factors for ebola virus disease in. In 2014, ebola virus disease evd in west africa was first reported during march in 3 southeastern prefectures in guinea.
Transmission of ebola virus disease evd ebolaviruses enter the human body via mucosal surfaces, abrasions and injuries in the skin or by direct parental transmission. Ebola virus disease evd, formerly known as ebola haemorrhagic fever ehf, is an acute, severe and fatal disease in humans. We describe the epidemiology of evd cases reported in guineas capital, conakry, and 4 surrounding prefectures coyah, dubreka, forecariah, and kindia, en. Introduction current outbreak of ebola virus ebov in west africa can be described as most severe public health emergency in modern times 1.
It is likely that, as for the index case, infection occurs. Ebola virus disease evd is a rare and deadly disease in people and nonhuman primates. The outbreak of ebola virus disease in senegal is over 17 october 2014 senegal is free of ebola virus transmission factors that contributed to success. 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 virus disease pathogenesis, clinical presentation and management abstract. Mar 10, 2015 ebola virus disease evd, formerly known as ebola haemorrhagic fever ehf, is an acute, severe and fatal disease in humans. Disease causing microbes are bacteria, virus, fungi, and. 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. The clinical manifestations, diagnosis, treatment, and prevention of ebola virus disease are discussed elsewhere. Working guideline for the management of patients having ebola virus disease evd case definition for ebola virus disease evd suspected case a person who has both consistent symptoms and risk factors as follows.
Without a specific treatment, management of patients with ebola virus disease consists of the provision of supportive and, as required and when possible, critical care, on the basis of the pathophysiological similarities between, on the one hand, ebola virus disease and, on the other hand, septic and possible hypovolaemic shock. Ebola surveillance guinea, liberia, and sierra leone mmwr. Surveillance for ebola virus disease ebola in the west african countries heavily affected by ebola guinea, liberia, and sierra leone faced numerous impediments, including insufficient numbers of trained staff, community reticence to report cases and contacts, limited information. We describe the epidemiology of evd cases reported in guineas capital, conakry, and 4 surrounding prefectures coyah, dubreka, forecariah, and kindia. Ebola virus disease evd is caused by viruses in the genus ebolavirus family filoviridae. A separate outbreak of ebola virus disease, which is not related to the outbreak in west africa, was laboratoryconfirmed on 26 august by the democratic republic of congo drc.
As of november 14, 2014, the world health organization has reported a total of 21,296 ebola virus disease evd. For almost 50 years, ebolaviruses and related filoviruses have been repeatedly reemerging across the vast equatorial belt of the african continent to cause epidemics of highly fatal hemorrhagic fever. The epidemiology and pathogenesis of ebola virus disease will be. Confirmed and probable ebola virus disease cases by week of illness onset, as of 2 december 2018 n444 table 1. In february 2014, the first case of evd occurred in guinea, followed by a rapid growth of the evd epidemic within the next nine months in west africa. Symptoms include fever, headache, joint and muscle aches, sore throat, and weakness, followed by diarrhea, vomiting and stomach pain. Ebola virus disease ebola virus disease formerly known as ebola haemorrhagic fever is a severe, often fatal illness, with a death rate of up to 90%. Ebola virus disease, viral haemorrhagic fever, filovirus. Ebola virus disease evd, or simply ebola, is a viral haemorrhagic fever of humans and other primates caused by ebolaviruses. An epidemiological analysis of ebola virus disease in west africa was performed based on 26 593 cases from march 2014 to may 2015. In march 2014, the largest ebola outbreak in history exploded across west africa. Epidemiology of epidemic ebola virus disease in conakry. 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. Early detection and response, aided by a detailed plan and a quicklyactivated national crisis committee.
The continued accumulation of epidemiologic data has advanced our understanding of zika. Ebola ebo subtype reston ebor virus was originally discovered in the united states in 1989 in association with an outbreak of viral hemorrhagic fever among cynomolgus monkeys macaca fascicularis exported from the philippines. Distribution of ebola virus disease cases by health zone in equateur province. Early detection, rapid patient isolation, contact tracing, and the ongoing vaccination programme should sufficiently control the outbreak. Current outbreak is the largest in the history, since discovery of. The current 201819 outbreak of ebola virus disease evd, ebola in the democratic republic of congo drc is the largest outbreak that has occurred in that country, and is the second largest of all evd outbreaks, following the 2014 west africa outbreak. The forecast of the number of cases does not exceed the current capacity to respond if the. Assessment of the severity of ebola virus disease in. The viruses that cause evd are located mainly in subsaharan africa. This virus was formerly known as the hemorrhagic fever. Ebola virus disease cases by classification and health zones in north kivu and ituri provinces, democratic republic of the congo, as of 3 december 2018. The most prevalent ebola virus belongs to the species of zaire ebolavirus, with a fatality rate as high as 90%. The outbreak started in guinea and rapidly spread to liberia and sierra leone, claiming thousands of lives. The forecast of the number of cases does not exceed the current capacity to.
At the onset of the epidemic, there was little information about the epidemiology, transmission dynamics, and risk factors in urban settings as previous outbreaks were limited to ruralsemirural settings. The outbreak started in guinea and rapidly spread to liberia and sierra leone, claiming. On march 2014 the who notified the outbreak of ebola virus disease evd in guinea, and infection quickly spread to another west african countries including sierra leone, liberia and nigeria. See epidemiology and pathogenesis of ebola virus disease and treatment and prevention of ebola virus disease. Ebola virus, the prototype virus of the genus, was first detected in zaire now the democratic republic of the congo in 1976 and is the virus responsible for the current outbreak in west africa. Ebola ebola virus diseases ebola hemorrhagic fever epidemiology.
Outbreak of ebola virus disease in the democratic republic. The genus ebolavirus is composed of singlestranded, enveloped, filamentous rna viruses, that, together with the marburgvirus genus, comprise the family filoviridae. Ebola virus disease evd is an infectious disease caused by a virus belonging to the filoviridae family of rna viruses. The ebola virus disease is an epidemic that has returned to claim more lives than one can count. Although there were cases introduced into other continents, africa is the. Ebola virus disease, pathogenesis, clinical presentation, diagnosis, treatment. 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. On march 23, 2014, the world health organization who announced that an ebola virus outbreak that started in the republic of guinea in december 20 had spread to numerous west african countries. Ebola virus disease evd evd is an infection characterized by sudden onset of fever and malaise, accompanied by other nonspecific signs and symptoms, such as fever, myalgia, headache, vomiting, and diarrhea.
The virus was first discovered during an outbreak dated back to the year 1976. Five distinct species of ebola virus have been isolated from various epidemics, mainly in african countries, with the exception of the reston virus that originated in the philippines. The number of potential cases ranges from thousands to millions with mortality rate up to 74% 2. 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. Chains of transmission and control of ebola virus disease in conakry, guinea, in 2014. Here, we propose a hypothesis of the evolutionary history of ebola virus which will be helpful to investigate the molecular evolution of these viruses. Subsequently, 4 other episodes of ebor virus infection among monkeys imported from the philippines have occurred in the. Genetic sequencing has shown that the virus isolated from infected patients in the 2014 outbreak is 97% similar to the virus that first emerged in 1976. Ebola virus disease evd is a lifethreatening viral disease with a fatality rate ranging from around 30% to 90%.
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. Ebola virus disease formerly known as ebola hemorrhagic fever is a rare and often deadly illness caused by the ebola virus. The exact source of ebola infections remains an open question, and. Information on this outbreak is provided in separate editions of the disease outbreak news. In this study, 27 ebola virus strains with complete glycoprotein genes, including five species zaire, sudan, reston, tai forest, bundibugyo, were analysed. Epidemiology and pathogenesis of ebola virus disease uptodate. Introductionwestern area wa of sierra leone including the capital, freetown, experienced an unprecedented outbreak of ebola from 2014 to 2015.
Compared to the peak of the outbreak, the number of new cases per day has decreased by 92. Ebola virus infection epidemiology bmj best practice. The first evd outbreak was reported in the 1970s in zaire now the democratic. Epidemiology of ebola virus disease transmission among. Ebola virus is the cause of a viral hemorrhagic fever disease. The clinical manifestations, diagnosis, treatment, and prevention of. Over the past 40 years, sporadic ebola virus disease evd outbreaks have occurred mostly in the central african region. Jul 22, 2017 no approved therapyis available for the treatment of these diseases, but progress has been made in new experimental approachesto postexposure prophylaxis andor treatment that are effective in laboratory primates 411. Forest fruit bats are regarded as the principal reservoir and may be eaten directly. 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. Frontiers epidemiology of ebola virus disease in the. Symptoms may appear anywhere from 2 to 21 days after exposure to ebola virus, though 810 day.519 1041 33 1072 1654 857 1574 518 653 1083 538 1519 1095 1060 382 1683 719 1471 708 256 264 605 1123 1092 1292 1546 1013 400 1487 1216 836 1080 1141 880 1039