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 benefits Uses: 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 fever Fatality 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 Identification Clinical 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 fever Prevention 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 Murphy, Frederick A. “Ebola Virus.” Encarta. CD-ROM. Microsoft, 2002 Russell, Brett. Ebola Information. 3/19/04 Col. Weeks, Byron, M.D. “Ebola – A Serious Threat.” NewsMax.com. Oct. 17, 2001. 3/19/04