Scientific Name: Ebola Virus

Filoviridae family4 strains – Ebola-Zaire, Ebola-

Sudan, Ebola-Cote d’Ivoire, Ebola-Reston

Common name: Ebola

Causes Ebola hemorrhagic fever

Description

• RNA strand virus– Coiled RNA in spike-covered envelope

from host cell• Long rods (800-1000 nm)• Replication = 8 hours

– Therefore, spreads rapidly

Natural Habitat = Africa

• Zaire (Democratic Republic of the Congo)– Ebola-Zaire

• Sudan– Ebola-Sudan

• Gabon• Ivory Coast

– Ebola-Cote d’Ivoire

• Uganda• Republic of the Congo

(not the DRC)

Ivory Coast

Gabon

Congo

DRC

Uganda

Sudan

Natural Reservoir

Suspected to be a zoonotic (animal-borne)

However, it is unknown what organism carries it naturally without being infected

Suspected vectors• Bats• Primates (in some cases, have

been confirmed)• Basically any other animal native

to Africa, including mosquitoes, ticks, birds, reptiles

No benefitsUses: Possible terror weapon

(no uses)

Never normal flora in humans(it really sucks)

Ebola hemorrhagic fever

Transmission

Ebola-Reston has shown to be airborne

The other three strains are transmitted by contact of any kind (fluids or skin)

Target Groups

Anyone who comes in contact with an infected animal or person is at high risk of contacting the disease.

However, some people seem to have natural defenses in their immune system that allow their bodies to kill the virus. Scientists do not know exactly how this occurs.

Ebola hemorrhagic fever

Target Organs and Damage Methods

Target mainly small capillary vessels. Attach to walls, cause leakage of blood and serum into surrounding tissue.

When white blood cells attack the virus, they dissolve – this releases a chemical into the blood stream that signals the release of other chemicals (pro-inflammatory cytokines, pro-coagulants, and anticoagulants)

These injure blood vessels even worse, resulting in permanent bleeding.

Eventually, the entire body is leaking and dissolving

Ebola hemorrhagic fever

Symptoms:• Severe headache• Weakness• Muscle aches

As it progresses:• Severe vomiting• Abdominal pain• Diarrhea• Pharyngitis• Conjunctivitis• External bleeding• Extremely high body

temperature• Prostration

Incubation Period: Anywhere from 2-21 days

Ebola hemorrhagic feverFatality Rates:• Ebola-Sudan – 60%• Ebola-Zaire – 77-88%• Ebola-Reston – Found in

monkeys, has not shown to be fatal in humans

• Ebola-Cote D’Ivoire – Only one human case recorded, patient survived

Not much is known about the body’s response because of the dangers of handling samples from infected patients and the short time span available for investigation.

MASS GRAVES FOR EBOLA VICTIMS

Ebola hemorrhagic fever

Diagnosis and IdentificationClinical Diagnosis:

-Difficult because early symptoms (red eye, skin rash) are nonspecific to virus.

-Takes a combination of many symptoms characteristic of Ebola.

Laboratory Testing/Diagnosis:-Antigen-capture enzyme-linked immunosorbent assay

(ELISA)-IgM ELISA test-Polymerase Chain Reaction (PCR) – a DNA test to match

the DNA from the sample to known Ebola DNA-All done within a few days of onset of symptoms

Ebola hemorrhagic fever

Diagnosis Continued

Advanced Stage Testing:

-Test for IgM and IgG anitbodies

Retrospective Testing:

-Immunohistochemistry testing

-Virus isolation

-PCR

(Occur after death)

Culture

Only grows in cells

Ebola hemorrhagic fever

THERE IS NO CURE FOR EBOLA HF

Care of Infected Persons:-Supportive therapy -Maintain oxygen status, BP-Balance fluids and electrolytes -Treatment of complicating infections

Experimental Treatment:-In the Kikwit outbreak in DRC, doctors transmitted blood from survivors to sufferers, hoping to transmit whatever antibodies helped them survive.

It is unknown whether or not survivors gain immunity from infection. Doctors believe it is possible, but because of the limited ability to test this theory, it remains to be seen.

Ebola hemorrhagic feverPrevention

Classified as Biosafety level 4 (greatest threat to humans)

Extensive precautions taken when dealing with suspected cases to limit transmission

• Several layers of protective clothing covering entire body (up to four)

• Complete equipment sterilization

• Quarantine of Ebola HF patients

Ebola hemorrhagic fever

Future outlook

A study released in December of 2003 showed that researchers studying infected monkeys have found a way to increase survival rates

100% of infected monkeys had been dying

These were injected with rNAPc2, a factor known to inhibit blood coagulation, a characteristic of Ebola HF

33% of these monkeys survived and regained health. All untreated monkeys died.

rNAPc2 is known to be relatively safe in humans – this method is being studied further

Sources

“Ebola Hemorrhagic Fever.” Special Pathogens Branch: Diseases. Nov. 26, 2003. Center for Disease Control and Prevention. 3/19/04 <http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/ebola.htm>

Murphy, Frederick A. “Ebola Virus.” Encarta. CD-ROM. Microsoft, 2002

Russell, Brett. Ebola Information. 3/19/04 <http://www.brettrussell.com/personal/ebola.html>

Col. Weeks, Byron, M.D. “Ebola – A Serious Threat.” NewsMax.com. Oct. 17, 2001. 3/19/04 <http://www.newsmax.com/archives/articles/2001/10/12/82239.shtml>