Ebola Virus Microbiology 401 Fall 2007 By: Shahrzad Morim Monica Delgado Janine Gilkes Case Study- Ebola Virus вЂў VECTOR- the State Research Center for Virology and Biotechnology branch вЂў вЂў вЂў Biosafety Level 4 Lab Designed specifically to create genetically altered viruses Bioweaponization- вЂў U.S. was considered вЂњdeep targetвЂќ вЂ“ potentially aerosolized вЂў The former Soviet Union вЂў Program: вЂ“ active state-supported bio-weapon research/production (1970вЂ™s to mid 90вЂ™s) вЂ“ worked with incurable pathogens While working to develop a vaccine against Ebola virus, one of the scientists accidentally stuck herself with a needle contaminated with virus. She contracted Ebola hemorrhagic fever and died. Ebola Virus Brief Background п‚§ Family Filoviridae п‚§ Genus Ebolavirus п‚§ History п‚§ First emerged in 1976 п‚§ Ebola River Valley, Africa п‚§ Sub-types (well-known) 1. 2. 3. 4. Zaire Sudan Reston Tai (Ivory Coast) п‚§ Classification п‚§ Enveloped п‚§ SS negative-sense RNA п‚§ Structure п‚§ Long, filamentous, вЂњthread-likeвЂќ structure of a filovirus п‚§ вЂњUвЂќ or вЂњ6вЂќ appearance Ebola Virus вЂў Structure-function analysis of the soluble glycoprotein, sGP, of Ebola virus вЂ“ Transmembrane protein, GP(1,2) вЂ“ GP gene encodes the soluble glycoproteins sGP and Deltapeptide. вЂў Genome has 7 genes: вЂ“ NP, VP35, VP40, GP, VP30, VP24, and L вЂў GP1 Viral Entry вЂў GP2 Fusion and Entry вЂў Likely pH dependent Currently Believed Animal Reservoir of Ebola Virus? вЂў Despite extensive studies, the natural and animal reservoir is unknown вЂ“ Seems to be the rain forests on the African continent and in the Western Pacific. вЂў Non-human primates as a source of infection for humans вЂ“ Carcasses of gorillas, chimpanzees and duikers during outbreaks in 2001 and 2003 вЂ“ High mortality from infection in these species disqualifies them from acting as reservoirs вЂў Other considered Reservoirs вЂ“ Plants, arthropods, and birds вЂў IRD researchers have identified bats as a potential natural reservoir of Ebola virus вЂ“ Of 24 plant species and 19 vertebrate species experimentally immunized with Ebola virus, only bats became infected. вЂў No clinical signs were observed in these bats вЂў This is characteristic of a reservoir species Currently Believed Animal Reservoir of Ebola Virus? вЂў Current proposal вЂ“ Bats вЂў Good vectors вЂ“ If bats are among the culprits вЂў Likely to pass virus to great apes пѓ humans вЂў May infect humans directly вЂ“ Dry season вЂў More contact because of food competition вЂў BatsвЂ™ immune systems modified вЂў Virus reproduces easier вЂў In 2001-03 вЂ“ Survey of 1,030 animals (including 679 bats) from Ebola-affected areas вЂ“ Found three bat species вЂ“ Viral genome fragments (RNA) in the liver and spleen вЂ“ Evidence of immune response вЂў antibodies against virus in the serum Transmission of Ebola Virus вЂў вЂў вЂў вЂў вЂў вЂў вЂў Direct contact вЂ“ Blood , secretions , organs Unsterilized needles Burial ceremonies Documented human infections вЂ“ Handling of infected chimpanzees, gorillas, forest antelopes Airborne transmission вЂ“ limited evidence of human-human Incubation period вЂ“ 2 to 21 days Contagiousness вЂ“ Not during early stages вЂ“ As the illness progresses, bodily fluids represent an extreme biohazard Symptoms of Ebola Virus Initial Signs вЂў Fever (at least 102В°F) вЂў Weakness & exhaustion вЂў Pain вЂ“ Severe headache вЂ“ Muscles & joints вЂ“ Abdominal pain вЂў Sore throat вЂў Nausea вЂў Dizziness Progressed Symptoms вЂў Vomiting вЂў Diarrhea вЂў Extensive bleeding вЂ“ Red eyes вЂў hemorrhage of sclerotic arterioles вЂ“ From mouth, nose, eyes, rectum & mucouse membranes вЂў Maculopapular rash вЂ“ Spreads over the body (often hemorrhagic) вЂў Other secondary symptoms вЂ“ Hypotension , Hypovolemia , Tachycardia вЂ“ Organ damage вЂ“ Internal and external bleeding Tissue Damage leads to Hemorrhaging вЂў вЂў вЂў вЂў вЂў вЂў вЂў Hemorrhagic fever syndrome late symptoms: вЂ“ toxic shock, hemorrhaging Direct tissue damage вЂў liver, combined with massive viremia Disseminated intravascular coagulopathy Endothelial susceptibility Subverts innate and adaptive immune responses Terminal stages вЂ“ diffuse bleeding, and hypotensive shock accounts for many Ebola virus fatalities Diagnostic вЂў Specialized laboratory test on blood specimens for detection of вЂ“ Antigens вЂ“ Genes of the virus вЂ“ Antibodies against the virus вЂў New techniques вЂ“ Non-invasive methods: saliva and urine samples вЂў Diagnosing вЂў ELISA Assay вЂў IgM ELISA вЂў PCR Courtesy of: http://www.ncbi.nlm.nih.gov Infection Prevention and Lab Safety Precautions вЂў Infection Prevention вЂ“ вЂ“ вЂ“ вЂ“ вЂ“ вЂ“ вЂў Isolation communication Limit direct contact Monitor those who had lose contact with infected Disinfect reusable equipment Sterilize equipment Lab Safety Precautions вЂ“ вЂ“ вЂ“ вЂ“ вЂ“ вЂ“ Education about organism Sterile environments Protective clothing Proper disposal of waste products Limit contact with contaminated medical equipment Communication Current Research On Vaccines вЂў One study found that guinea pigs were protected from Ebola virus infection by immunization with plasmids containing the viral genes for either the secreted or transmembrane forms of the viral glycoprotein (GP). This protection was correlated with antibody titer and antigen-specific T-cell responses to secreted GP or membrane GP. вЂў Another study found that harmless-Ebola-like particles (eVLPs) could confer immunological protection from Ebola virus infection. These eVLPs were found to be immunogenic both in vitro and in vivo. Mice were vaccinated with these eVLPs, and developed high titers of Ebola virus specific antibodies, including neutralizing antibodies. Additionally, all the mice in the study were protected from Ebola virus inoculation. Bio-Warfare вЂў Biological warfare (BW) aka biological weapons, is the use of any pathogen, bacteria or virus as a weapon of war. вЂў After initial release of virus, secondary infections may occur as a result of infected individuals traveling from areas of contamination to other locations. вЂў In 1972 the Biological Weapons Convention outlawed creation and storage, but not usage, of these weapons. Benefits and Hazards of U.S Aid вЂў Benefits of US Aid вЂў Hazards of US Aid - Russian Allies - VECTOR removed from - Collaborative efforts in finding a cure for Ebola - Decreased Fear - A cut of the profits biowarfare threat list; however, 4 other weapons labs exist with no U.S. inspection - Difficult to verify whether former Soviet Scientists are using the American supported research for peaceful purposes - Lack of Accountability Which is more dangerous As a Potential Bio-Weapon? Ebola Virus вЂ“ CDC classifies it as: вЂў Category A bioterrorism agent вЂ“ Sudden, severe onset of symptoms вЂ“ Believed to hide out in animals вЂ“ No approved vaccine or treatment вЂ“ Short incubation period Smallpox Virus вЂ“ CDC classifies as вЂў Category A bioterrorism agent вЂ“ Incubation period between contraction and the first obvious symptoms of the disease is usu. 12-14 days вЂ“ Initially vague, flu-like symptoms, turn into severe symptoms (fever, severe pain, characteristic rash) вЂ“ Humans are the only natural host вЂ“ Historic death rate of 1 in 3 вЂ“ Vaccination in 1967 вЂў May kill victim before вЂў Effective if administered up to 4 days transmitted to others (high after viral exposure and before rash appearance death rate) вЂў Outbreaks seem to burn out вЂ“ No effective treatment quickly вЂ“ In 1979, WHO declared eradication Smallpox (Variola Virus) вЂў Genus: orthopoxvirus вЂў DS DNA: one of the largest viral genomes вЂў Relatively stable вЂ“ If aerosolized, infective for at least several hours (without sunlight or UV exposure) вЂў Acute contagious disease вЂ“ Two main forms вЂў Variola major (30% fatal) вЂў Variola minor (<1% fatal) вЂ“ Two rare forms (almost always fatal) вЂў Hemorrhagic вЂў Malignant Which is more dangerous As a Potential Bio-Weapon? вЂў CDC: an agent must have the following properties to be used for a maximum credible event вЂ“ вЂ“ вЂ“ вЂ“ Be highly lethal Be easily produced in large quantities Be communicable from person to person Have no treatment or vaccine вЂў Smallpox вЂ“ Extremely contagious вЂў Transmission through air вЂ“ вЂ“ вЂ“ вЂ“ Can be produced in large scale Can spread in any climate or season Contaminates in a short time Preventive measures/treatments вЂў Routine smallpox vaccination was discontinued in the U.S. in 1972 вЂў Limited vaccine with questionable potency вЂў Vaccine complications References 1) Adamcek, K., Eanes, M., Shaw, S., Virology Project: Ebola Virus. Retrieved: 11/8/07 вЂў http://www.biosci.ohiou.edu/virology/Ebola 2) Miller, J. Russian Scientist Dies in Ebola Accident at Former Weapons Lab. The New York Times. Published: 5/25/2004. Retrieved: 11/12/2007 вЂў http://query.nytimes.com 3) Pappalardo, J. From Russia, with bugs [US subsidizing Russian Biological Warfare Lab]. Dallas Observer. Published: 6/22/2000. Retrieved: 11/14/07 вЂў http://freepublic.com 4) вЂњBiological Warfare.вЂќ Wikipedia: The Free Encyclopedia. Retrieved: 11/12/07 вЂў www.wikipedia.org 5) Emerging Infectious Diseases. National Center for Infectious Diseases. Vol. 5, No.4, July-Aug 1999. Retrieved 11/8/07 вЂў http://www.cdc.gov/ncidod/eid/vol5no4/pdf/v5n4.pdf 6) Tanna, J.H, Preventing вЂњDark WinterвЂќ-The Public Health SystemвЂ™s Role in Strengthening National Security. Vol. 1, No.4, Spring 2002. Retrieved 11/8/07 http://www.carnegie.org/reporter/04/preventing/index.html 7) Leroy, E., Fruit Bats a Reservoir for Ebola Virus. Indigo Base, IRD. November 2005. Retrieved 11/8/07 www.ird.fr/us/actualities/fiches/2005/fiche231.htm 8) World Health Organization. Ebola Haemorrhagic Fever. Retrieved 11/8/07 Refrences вЂў http://www.who.int/mediacentre/factsheets/fs103/en/ 9) Hoenen et al. Ebola Virus: Unravelling Pathogenesis to Combat a Deadly Disease. Trends Mol. Med. May 2006, 12(5): 206-215 10) Leroy, EM, Kimulugui, B, Pourrut, X et al. Fruit Bats as Reservoirs of Ebola Virus. Nature. 2005. 438:575вЂ“576 11) Pourrut, X, Kumulungui, B, Wittmann, T et al. The Natural History of Ebola Virus in Africa. Microbes and Infection. 2005. 7:1005вЂ“1014 12) Retrieved 11/11/07 вЂў http://www.nytimes.com/packages/html/health/20030506_Ebola_COMPARE/sci_Ebola_COMPARE_01.html# 13) World Health Organization. Smallpox. Retrieved 11/8/07 вЂў http://www.who.int/mediacentre/factsheets/smallpox/en/ 14) September 2003, p. 9733-9737, Vol. 77, No. 18 0022-538 15) BMC Microbiology 2003 3:6 doi:10.1186/1471-2180-3-6 16) www.biomedcentral.com/1471-2180/3/6/figure/F3 www.biosci.ohiou.edu/virology/Ebola/Dectec3.jpg (Courtesy of http://www.ncbi.nlm.nih.gov/ICTVdb/Images/Murphy/ebola_cell.htm 17) World Health Organization вЂў http://www.who.int/mediacentre/factsheets/fs103/en/ вЂў Provisional Revision: 2007 18) Leroy, Eric M., et al. Multibple Ebola Virus Transmission Events and Rapid Decline of Central African Wildlife. Science 303: 387 -389. 2004 19) Facts sheet: Community Health Administration вЂў http://edcp.org/factsheets/ebola.html Journal of Virology Thank you!