Many different viruses can cause vhf, including ebola, marburg, and lassa viruses. Marburg virus is the causative agent of marburg virus disease mvd, a disease with a case fatality ratio of up to 88%. Ebola virus ebov and marburg virus marv infections cause a severe form of viral hemorrhagic fever vhf with lethality in humans ranging from 2390% depending on the virus species and strain sanchez et al. Agents of ebola virus disease or viral hemorrhagic fever include four main viral families filoviruses, arenaviruses, bunyaviruses, flaviviruses. This book is a compilation not only of her work but of all the information available on marburg and ebola viruses. Ebola and marburg virus diseases are said to occur at a low prevalence, but are very severe diseases with high lethalities. Molecular evolutionary analyses for ebola and marburg viruses were conducted with the aim of elucidating evolutionary features of these viruses. How severe and prevalent are ebola and marburg viruses.
It spreads to people by contact with the skin or bodily fluids of an infected animal, like a monkey, chimp, or. Some poachers and villagers who kill and eat monkeys have antibodies to ebola virus surface glycoprotein genes of ebola virus strain responsible for latest outbreak in zaire nearly matches the strain that caused a similar outbreak in 1976 improper hospital hygiene, and local burial practices helped in virus spread mortality is more than 90%. The ebola and marburg filoviruses are among the most pathogenic viruses in the world. The emerging viruses section of virology journal includes studies covering all aspects of new and reemerging viruses that cause severe andor lethal diseases in humans and animals. The ebola and marburg viruses are known as filoviruses, and result in lifethreatening hemorrhaging in humans and other primates. Ebola, also known as ebola virus disease evd, is a viral haemorrhagic fever of humans and other primates caused by ebolaviruses. Ebola viruses are found in several african countries. Ebola and marburg viruses have caused outbreaks in the past, mostly in subsaharan tropical countries, notably in the central africa region.
Infectious hemorrhagic fevers caused by the marburg and ebola filoviruses result in human mortality rates of up to 90%, and there are no effective vaccines or therapeutics available for clinical use. Both viruses are native to africa, where sporadic outbreaks have occurred for decades. Vhfs are clinically difficult to diagnose and to distinguish. The five species of ebola virus are the only other known members of the filovirus family. A view of infection using electron microscopy elena i. However, tests cannot determine whether live ebola virus is present and capable of spreading disease.
Ebola virus genome encodes seven proteins, including a nucleo protein, four virion structural proteins vp35, vp40, vp30, vp24,glycoproteingp,andrnadependentrnapolymerase. Marburg and ebola viruses are the two members of the filoviridae family filovirus. Marburg and ebola viruses are both members of the filoviridae family filovirus. Ebola virus genetic material persisted for a year or longer in the semen of 63% men who recovered from ebola. Marburg hf is caused by marburg virus, a genetically unique zoonotic or, animalborne rna virus of the filovirus family. These are known as hemorrhagic viruses, because they can cause severe bleeding. How ebola and marburg viruses battle the immune system. The genome of all filoviruses is a linear, nonsegmented, singlestranded rna molecule.
Of the 2 870 marburg and ebola cases documented between june 1967 and june 2011, 270 9% were healthcare workers. In particular, the rate of nonsynonymous substitutions for the glycoprotein gene of ebola virus was estimated to be, on the average, 3. Ebola can cause disease in humans and nonhuman primates monkeys, gorillas, and chimpanzees. Pdf the origin and evolution of ebola and marburg viruses. The names of these viruses have undergone several taxonomic changes since they were first. The known animal viruses are remarkably diverse in the ways in which they sustain themselves in nature, occasionally wreaking havoc in their preferred or accidental hosts. Ebola and marburg viruses have caused outbreaks in the past, mostly in subsaharan tropical countries, notably in. Ebola and marburg viruses are the causative agents of a severe form of viral hemorrhagic fever. The highly infectious and lethal nature of these viruses highlights the need for reliable and sensitive diagnostic methods. Ebola and marburg viruses are rare but have caused periodic cases and deadly outbreaks in africa since they were first recognized.
Marburg virus is a hemorrhagic fever virus of the filoviridae family of viruses and a member of the species marburg marburgvirus, genus marburgvirus. Ebola and marburg virus disease epidemics preparedness, alert. Ebolavirus, marburgvirus, and cuevavirus tentative 1. Ebola virus and marburg virus live in animal hosts, and humans can contract the. We assembled a protein microarray displaying nucleoprotein np, virion. Given the high virulence in humans and the classification of these viruses as biosafety level 4 and category a list pathogens, animal models are. These viruses started in africa, and that is where most cases of the. Marburg hemorrhagic fever marburg hf is a rare but severe hemorrhagic fever which affects both humans and nonhuman primates.
Viral hemorrhagic fevers vhfs are acute infections with high case fatality rates. Vomiting, diarrhoea and rash usually follow, along with decreased function of the liver and kidneys. The genus ebolavirus is composed of singlestranded, enveloped, filamentous rna viruses, that, together with the marburgvirus genus, comprise the family filoviridae. Though caused by different viruses, the two diseases are clinically similar. The immune system is central in this battle for survival, which is exemplified here by the cases of ebola and marburg virus ebov and marv, respectively infections in primates. Ebola isnt as contagious as more common viruses like colds, influenza, or measles. The filoviruses ebolavirus and marburgvirus are among the deadliest viral pathogens known to infect humans, causing emerging diseases with fatality rates of up to 90% during some outbreaks. Jun 28, 2010 the ebola and marburg viruses are known as filoviruses, and result in lifethreatening hemorrhaging in humans and other primates. Ebola and marburg viruses may be much older than thought. Ebola is caused by infection with a virus of the family filoviridae, genus ebolavirus.
Their natural reservoir has not been definitely identified, but certain species of african bat have been associated with ebola. Etiology ebola and marburg hemorrhagic fevers are caused by members of the genera ebolavirus and marburgvirus, respectively, in the family filoviridae. Lassa, marburg, ebola, crimeancongo, and other emerging viruses what are they. These viruses are pathogenic in humans and cause isolated infections or epidemics of viral hemorrhagic fever, mainly in central africa.
In particular, the rate of nonsynonymous substitutions for the glycoprotein gene of ebola virus was estimated to. The viruses are members of the family filoviridae, a group of membraneenveloped filamentous rna viruses. Some parts of africa are particularly affected by outbreaks. Viral hemorrhagic fevers lassa, marburg, ebola, crimean. Both remain rare diseases, but have the potential to cause outbreaks with high case fatality rates. The filoviruses ebola and marburg are zoonotic agents that are classified as both biosafety level 4 and category a list pathogens. Ebola and marburg virus diseases are rare but often deadly diseases that are caused by the ebola or marburg virus.
Marburg virus was also suggested to be evolving at a similar rate. Resources marburg hemorrhagic fever marburg hf cdc. A person who is sick with one of these viruses can spread the infection to others. Infection with marburg and ebola viruses cause haemorrhagic fevers that are characterized by organ malfunction, bleeding complications, and high mortality.
Signs and symptoms typically start between two days and three weeks after contracting the virus with a fever, sore throat, muscular pain, and headaches. Wellknown agents are ebola, marburg and dengue viruses also see hantavirus and yellow fever guidelines. Ebola and marburg virus diseases are caused by the ebola and marburg viruses respectively. Ebola virus and marburg viruses flashcards quizlet. Jun 7, 2005 cidrap news a pair of vaccines created by a canadianbased international team of researchers protected monkeys against the lethal ebola and marburg viruses, according to a new report in nature medicine the vaccines were made by splicing a gene from either the ebola or the marburg virus into a weakened version of the vesicular stomatitis virus, which causes mouth. As of the end of march 2016, the west africa epidemic of ebola virus disease ebola had resulted in a total of 28,646 cases, 11,323 of them fatal, reported to the world health organization. Ebola spotlight emerging infectious diseases journal cdc. Monovalent viruslike particle vaccine protects guinea pigs and nonhuman primates against infection with multiple marburg viruses.
The emerging viruses section of virology journal includes studies covering all aspects of new and reemerging viruses that cause severe and or lethal diseases in humans and animals. The bleeding or hemorrhaging caused by the virus is not usually life threatening but damage to. In order to provide healthcare workers in risk areas with a working tool to combat ebola virus disease. Both viruses belong to the filoviridae family, which contains two genera and a newly proposed 3rd genus. We aimed to use a metaanalysis approach to estimate the case fatality and. Marburg and ebola viruses epidemiologic data sudan ebolavirus 1976 cases. Five distinct species of the genus ebolavirus have been reported. Oct 20, 2017 marburg virus is the causative agent of marburg virus disease mvd, a disease with a case fatality ratio of up to 88%.
Determination of specific antibody responses to the six. Marburg hemorrhagic fever, ebola hemorrhagic fever. They are responsible for outbreaks of hemorrhagic fevers in human and nonhuman primates, as well as other vertebrates, causing many deaths feldmann et al. Important vhf agents are ebola and marburg viruses mbgvebov, lassa virus lasv, crimeancongo hemorrhagic fever virus cchfv, rift valley fever virus rvfv, dengue virus denv, and yellow fever virus yfv. Host and viral proteins modulating ebola and marburg virus. There are five identified ebola virus species, four of which are known to cause disease in humans.
Outbreaks occur in remote locations in africa, and while rare. Marburg virus transmission via infected semen has been documented up to 7 weeks after clinical recovery. These viruses affect multiple organs in the body by damaging the vascular blood vessel system. Ebolaviruses and marburgviruses are singlestranded, negativesense, nonsegmented rna viruses belonging to the family filoviridae, order mononegavirales table 1. Marburg haemorrhagic fever was initially detected in 1967 after simultaneous outbreaks in marburg, from which the disease takes its name, and frankfurt in germany. Marburg and ebola virus infections infectious diseases. Ebola or marburg virus disease outbreaks constitute a major public health issue in subsaharan africa. Marburg haemorrhagic fever was initially detected in 1967 after simultaneous outbreaks in marburg and frankfurt in germany. In addition, serosurveys conducted have shown different seropositivity for both ebola and marburg viruses. Ebola and marburg virus disease epidemics preparedness.
The replication cycles of these viruses are comprised of numerous complex molecular processes and interactions with their human host, with one key feature being the means by which nascent virions exit. Marburg virus brazil pdf ppt case reports symptoms. Serious cases involve severe hemorrhagic manifestations. Marburg virus marv causes marburg virus disease in humans and nonhuman primates, a form of viral hemorrhagic fever. Rapid detection and quantification of rna of ebola and. Examples of these viruses include filoviruses ebola, marburg, henipaviruses nipah, hendra, lassa virus, lujo virus, south american hemorrhagic fever viruses. Viral hemorrhagic fevers are a group of illnesses causes by several viruses. The largest outbreak of ebola virus disease, which occurred in west africa from 2014 to 2016, caused more than 28,600 infections and more than 11,300 deaths, according to the world health organization. Ebola virus and marburg virus are related viruses that cause hemorrhagic fevers illnesses marked by severe bleeding hemorrhage, organ failure and, in many cases, death. Ebola virus and marburg virus mayo clinic mayo clinic. The fatality rates reported in different outbreaks ranged from 24100%.
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