Ebola Hemorrhagic Fever

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Ebola:
* What is Ebola?
Ebola is a virus that causes Ebola hemorrhagic fever (Ebola HF). The Ebola virus belongs to the RNA virus family known as Filoviridae. There have been five strains of the Ebola virus identified (four of them are known to cause illness in humans). * Ebola Genome: One of two RNA viruses

* First Recognized: 1976 Zaire Africa
* Native to Africa
* Unknown Origin, or natural reservoir
* Ebola is very acute, infection is very rapid so
* There are no known effective treatments or vaccines for EBOV infection in humans, which makes the EBOV a potential bioterrorist agent.

Summary
The focus of this webpage is to describe the characteristics of the family of viruses Filoviridae specifically the Ebola virus strain. We will describe the mechanisms by which this virus infects a host, causing disease and eventually death for the majority of victims. We will also describe possibilities for treatment and therapies, and ongoing efforts to eradicate this deadly virus. Intro to Ebola virus

Ebola virions are capable of infecting a very wide range of different host cell types. This includes humans, nonhuman primates, rodents and bats. This virus is of unknown etiology but is suspected to originate from a bat reservoir. This is suspected because it was reported in 2005 that three species of fruit bats had symptomless infection (BCM). Structure

Filovirus has unenveloped helical morphology, with a single stranded negative sense RNA genome. This virus inherits a U or corkscrew shape that extends about 800 to 1000 nm. (11) (5)
Ebola Classification and Taxonomy
Ebola causes viral hemorrhagic fever from the order Mononegavirales found in the family of Filoviridae viruses. Within the Filoviridae family there are two genera Ebolavirus and Marburgvirus. There are five species in the Ebolavirus genus and two in the Marburgvirus see table 1. They are enveloped particles with single stranded RNA genome. Gene is about 19kb long. A single glycoprotein forms spikes on the virion surface. The nucleocapsid contains the RNA and viral structural proteins. http://www.stanford.edu/group/virus/filo/structure2.gif

Table 1
Family| Genus| Species|
Filoviridae| Ebolavirus| Ebola virus, Bundibugyo virus, Sudan virus, Tai Forest virus, Reston virus| | Marburgvirus| Ravn Virus, Marburg virus|

Cellular protein TIM-1 acts as a receptor for Ebola virus and Marburg virus. Microscope image shows TIM-1 expression (in green) on the surface of human airway cells. (Credit: University of Iowa)

Replication
The Virus attaches to the cell receptor via glycoprotein surface and undergoes endocytosis into the host cell. The virus envelope membrane fuses with the cellular membrane. The single stranded (-) RNA encodes into the cytoplasm. The virus uses the cells mRNA to transcribe the protein. The negative strand is used as a template to transcribe the positive strand. The positive strand is used as a replication template to make more of the negative strand. The protein and the genome are assembled together and the virus is released from the cell through budding taking part of the plasma membrane. (11) Infection and Multiplication

When ingested, Ebola finds its way to the bloodstream or the fluid in the tissue. It eventually penetrates to the tissue wall where multiplication begins. The incubation for the disease is five to seven days if contracted through needles and six to twelve days if contracted through person to person. Maximum days it will take for transmission would be twenty-one days. Ebola, spread through the blood vessels and is replicated in the organs throughout the body which includes liver, lymphatic, kidney, ovaries and tastes. The most dangerous place of infection is the liver cells and macrophages....
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