EbolaAlex Long

Classification

• Family: Filoviridae• Genus: Ebolavirus

• The Filoviridae family of viruses are thread-like viruses.• The family consists of Ebola-like Viruses and Marburg-like viruses• Both Marburg and Ebola cause hemorrhagic fevers, however, Ebola

is generally more severe.• There are five different strains of Ebola

How Ebola Replicates• The Ebola genome is single-stranded RNA. It infects many

cells related to the lymphatic system, but will go after nearly any type of cell.

• Ebola inserts itself into the target cell, and releases its -ssRNA into the cell.

• Transcriptase converts the negative RNA into positive RNA, that is used to create viral proteins. The proteins are assembled and create new copies of the virus

• The new viruses bud out of the cell, using some of the cell’s membrane to create a viral envelope.

Symptoms of Ebola• Ebola hemorrhagic fever starts

with headaches, muscle pain and general weakness.• Next, the patient will experience

stomach pain, diarrhea, vomiting, red eyes and skin rashes.• Internal and external bleeding is

common, but can be extreme in some cases.

Extreme cases of Ebola• In extreme cases of Ebola, there is uncontrollable internal

and external bleeding. • The blood clots in organs, and the rest of the blood cannot

clot.• Blood pours out of any and all orifices, and will not stop.• Parts of the brain die when they are clogged up with clotted

blood, so psychosis is common in extreme cases.• The virus liquefies organs and connective tissue, so the skin

starts to detach from the flesh, and organs are turned into a dark colored fluid.

• Once a patient develops an extreme case of Ebola, it is very likely that they will die.

Strains of Ebola

Sudan Ebolavirus• First outbreak occurred in

July of 1976 in a cotton factory in Sudan.

• A desk worker was infected, and soon spread the disease to coworkers and family members

• 284 people were infected, and 151 died, a 53% mortality rate.

Zaire Ebolavirus• Outbreak occurred in August

of 1976 in Zaire, near the Ebola River.

• A school teacher was possibly infected while on vacation, and the disease was spread through the use of dirty needles to give malaria medicine.

• 318 people were infected, 280 died, an 88% mortality rate.

Strains of Ebola

Ivory Coast Ebolavirus• Only one human case of

Ivory Coast Ebolavirus• A researcher was performing

necropsies of chimpanzees dying of Ebola in the Tai forest

• She fell ill with Ebola and was flown to Switzerland for treatment, where she survived.

• 0% mortality rate

Bundibugyo Ebolavirus• Most recent outbreak.• Occurred in November 2007

in the Bundibugyo district of Uganda

• 149 people broke with Ebola, and 37 died, a 25% mortality rate.

Strains of Ebola- Reston• Reston Ebolavirus was discovered in Reston, Virginia in 1989.• Monkeys imported from the Philippines by Hazelton Laboratories

were infected, and spread the virus throughout the building.• A team from the U.S. Army Medical Research Institute of Infectious

Diseases (USAMRIID) was sent to exterminate the virus.• Scientists from USAMRIID made the shocking discovery that

Reston Ebolavirus could easily spread through the air, making it from infected rooms of monkeys to uninfected ones through air vents.

• The monkey care-takers later tested positive for Reston Ebolavirus, however none of them ever became ill.

• The Reston strain has since been discovered in monkeys in Texas and Italy, as well as in pigs in the Philippines.

Treatment of Ebola• Once infected, there is no cure for Ebola.• The treatment that patients are given is supportive

treatment, such as oxygen, blood transfusions and liquids to combat dehydration.

• Minimally invasive procedures are also important, since a patient’s blood often does not clot.

• There has been a medication developed that, when given in proper dosages, can protect monkeys from developing disease after being infected with Ebola, however the medicine must be given 30 minutes after infection, so it will only be useful in a laboratory setting.

Prevention• Since there is no cure for Ebola, prevention is key.• The first outbreaks of Ebola were often spread by the use of

dirty needles, so clean needles are very important, especially during an outbreak.

• Also, medical staff must use protective clothing and face masks to avoid getting the disease.

• Isolation of patients is very important because although the virus has never been spread through the air in a clinic setting, it is possible.

• Families of patients must be convinced not to perform traditional burial rites, because it will cause them to come into contact with infectious fluid.

Natural Reservoir• Ebola still has no known natural reservoir.• Since it causes disease with such high mortality rates in primates,

the natural reservoir is definitely not a primate• Scientists have linked outbreaks to contact with fruit bats, and

since fruit bats can be infected without falling ill, they are believed to be the natural reservoir.

• Most humans are infected through contact with infected animals, not the natural reservoir.

• Ebola can be transmitted by eating meat of infected animals, or by contact with infected bodily fluids.

Ebola Vaccine• Scientists at USAMRIID have developed an Ebola vaccine, however

it is far from being allowed for use in humans.• The vaccine contains pieces of glycoproteins from the Zaire and

Sudan strains inserted into a common cold virus.• Once injected, the body produces antibodies to the glycoproteins.• 4 monkeys were given the vaccine and when infected, all four

survived (all 4 controls died). Surprisingly, the vaccine also protects against Ebola Bundibugyo.

• Since it will be difficult to test an Ebola vaccine in humans, the FDA has agreed to accept proof of animal efficacy to approve an Ebola vaccine, however more research is needed.

• Researchers in African gorilla sanctuaries hope to use a vaccine to protect gorillas from Ebola