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Transcript of Ebola Virus
Ebola VirusBy: Giselle and MattFamily of Ebola VirusFiloviridae Comes from the Latin filo meaning threadlike Two membersMarburgEbola VirusFive SpeciesZaire SudanRestonIvory CoastBundibugyo
Very in shape long sometimes branched filamentsShorter filaments shaped like a 6 or U sometimes a circle.Filaments measure from 80nm (Average) to 14,000nm.Enveloped virionSingle-strand negative sense RNA
ProteinsFive proteins in filovirusesGlycoproteinNucleocapsidTranscriptase-polymeraseRNA dependent RNA transcriptase polymerasematrix
http://s3.amazonaws.com/mmc-digi-beta-production/assets/9929/ebola_article.jpgHistoryDiscovered in 1974. Received it named from the first victims found from the Ebola River Valley in the Democratic Republic of the Congo.
StrainsZaire90% mortality rate. 276 out of 300 died.Sudan50% morality rate.150 out of 285 died.RestonFound 1989infected monkeys in the PhilippinesThe only airborne strain of Ebola virus.Later found that this strain is not harmful to humans but very devastating to monkeys.However four people known to have developed antibodies to this strain.Ivory CoastFound in monkey being autopsied by a scientist in 1994.Scientist became ill from the virus but survived.BundibugyoMost recently discovered strain of Ebola virus.Has less power to kill when compared to other strains.25%morality rate.37 out of 150 died.
High fever Muscle aches Sore throat Fatigue
Followed by:Stomach pain Diarrhea Rash Vomiting
Some may experience:Internal and external bleedinghttp://tbn1.google.com/images?q=tbn:WlRR-SZJ1Vr5vM:http://2.bp.blogspot.com/_PDbJY8bhKvI/SN8ZhlvmHEI/AAAAAAAAABo/dqb85gVB8mE/s320/HY_ebola_01.jpghttp://www.youtube.com/watch?v=3FI5KYk62bs&feature=channel
Virion ReplicationEnveloped viron membrane surrounding the virus.Phospholipids bilayerWith embedded proteins (spikes)Facilitate penetration of the virus into the hosts cells cytoplasm.AdsorptionSpike shape complements a hosts cell protein.Ebola attaches and is endocytosed into the cell.PenetrationThe virus membrane fuses to the hosts membrane.Nucleocapsid is released into the cytoplasm.SynthesisOccurs in the cytoplasmMake more Capsid proteinsGenomeHost uses host mechanismsTranscription- used to synthesize (-) sense RNA for encapsulationTranslation- make more viral proteins.MaturationAssembly of new virions made inside the cytoplasm.ReleaseThe Ebola virus uses the TSG101 pathway.This is the same pathway as HIV .ExocytosisNewly formed Ebola Virus bud from cell membrane and released.Infected host cell remains alive to continue viral replication.
Virion Replication Continued..
http://content.nejm.org/content/vol352/issue25/images/large/17f1.jpegCell Ebola targetsThe main cells it will attack are fibroblastic reticular cellswhich form much of the connective tissue.These cells are under the skin and close by to blood and lymph vessels.This allows the virus to spread easily in the body.
Ebola will then go on and attack any other connective tissue and epithelial tissue.This is what causes the hemorrhaging portion of the symptoms.The virus then moves on to liver and kidney cells.
Evading the Immune SystemEbola once again works similar to HIV in how it evades the immune system.There is a cellular protein called tetherin This protein does not save the infected cell.It prevents the virions from budding off into endosome and escaping.Ebola disables tetherin like HIV does. This allows the virus to bud out of the cell.Transmission from host to hostThe virus spreads similar to HIV.It spreads through bloody fluids such a blood, semen, and feces.The only exception is the Reston Ebola virusshown to be air bornlucky for us it only attacks monkeys. The outbreaks usually happen when a human gets the disease from an animal.This is known as a zoonotic infection (from animal to human).Then the infected person infects family and friends and hospital staff.
This can be contributed to the fact these outbreaks happen some of the poorest nations .In the nations of Africa there is a severe lack of resources especially in medicine. The nurses have limited or no personal protective equipment. They also have to reuse syringes that do not get cleaned properly.This not only spreads Ebola, but it also spreads HIV and other diseases.
VaccineExperimental vaccineBeing evaluated on infected primates.Vaccine has a recombinant inhibitor factor.33% survival rate
Although this experimental vaccine shows promising results there are no anti-viral drugs available for clinical use.
The lack of a cure and vaccine makes Ebola a level 4 biohazard.Level 4 biohazards are kept in special labs known as level 4 biosafety labs.The first level is for microbial agents that do not cause harm to humans.The second level is for microbial agents that do cause human disease but transmission is limited.The third level is for microbial agents that cause severe infections and easily transmitted to humans.The fourth level is for microbial agents that have no cure or vaccine. They are also highly contagious and pose a significant health threat.
Isolation of the virus for 2-22 days.There is no treatment for filoviruses.Treatments of symptoms:Keeping fluid and electrolyte levels balanced.Maintaining blood pressure and oxygenlevels.Blood transfusions.Cause of death:NormallyOrgan shock or failure associated with fluid and blood loss.It is still unknown why some infected recover while others die. But those that die have not had a significant immune response before death.http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/090327-ebola-scientist-hmed.300w.jpgBioterrorismThe possibility of a bioterrorist attack using Ebola is unlikely. The natural reservoir isunknown.The virus is held in highlyguarded labs.Ebola would make an effectiveWeapon because of:the fear it would instill in people.how quickly the virus kills and spreads.