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EBOLA
VIRUS
• Veronica M.B. Ebo
• 09333161116
Content1. Definition2. History3. Distribution4. Epidemiology5. Life cycle6. Symptomology7. Diagnosis8. Prognosis
9. Treatment10. Recomendation
What is Ebola Virus?• A notoriously deadly virus that
causes fearsome symptoms–High Fever–Internal Bleeding
• kills as many as 90% of the people it infects
• EBOV is a Select Agent, World Health Organization Risk Group 4 Pathogen– use of a positive pressure
personnel suit, with a segregated air supply, is mandatory
• capable of causing hemorrhagic (bloody) fever
• belongs to the Filoviridae family (filovirus)
5 species of ebolavirus1. Bundibugyo (Uganda)2. Zaire ( Democratic Republic of
Congo)3. Sudan4. Côte d’Ivoire5. Reston
• Zaïre, Sudan and Bundibugyo species have been associated with large Ebola haemorrhagic fever (EHF) outbreaks in Africa with high case fatality ratio (25–90%)
• Côte d’Ivoire and Reston have not• Reston can infect humans but no serious
illness or death in humans have been reported to date.
• Ebola Reston subtype, found in the Western Pacific, has only caused asymptomatic illness, meaning that those who contract the disease do not experience clinical illness.
Medical personnel aiding in
ZAIRE
History• The Ebola virus was first identified in
the western equatorial province of Sudan and in a nearby region of Zaire in 1976 after significant epidemics in Nzara, southern Sudan and Yambuku, northern Zaire.
• Named after a river in Zaire
• morphologically identical to Marburg Virus; the cause of deadly outbreaks of hemorrhagic fever in Germany and Yugoslavia in 1967, but serologically distinct.
• The estimated case-fatality rate was over 50% in Sudan, and more than 80% in Zaire
MARBURG VIRUS
• The first case at Kikwit General Hospital was admitted on 9 April. He
had previously been admitted to another hospital in Kikwit with a
differential diagnosis of typhoid fever with intestinal perforation. A
laparotomy was performed on the patient at Kikwit General Hospital on 10 April. Three days later, on 14 April,
the patient died.
• Medical personnel who had taken care of this patient, either in the operating
theatre or in the hospital wards, became ill with fever starting 14 April.
About three-quarters of the first 70 patients in the epidemic appear to have been health workers, and the
case fatality-rate was very high in the group
KIKWIT
• In this outbreak, at least four generations of cases can be distinguished
• 1st - spouses, other relatives and close friends of those infected at the hospital, infected either during patient care or preparation of bodies for burial
• 2nd&3rd-other relatives and friends of the first generation who were infected in a similar manner
• 4th-those who tended the second and third generation cases
Distribution• Epidemics of Ebola virus have
occurred mainly in African countries: Zaire (Democratic Republic of Congo), Gabon, Uganda, Côte d’Ivoire, and Sudan
• Ebola virus is a hazard to laboratory workers and, for that matter, anyone who is exposed to it.
Cases of Ebola Hemorrhagic Fever in Africa, 1976 - 2008
Country Town Cases Deaths Species Year
Dem. Rep. of Congo Yambuku 318 280 Ezaire 1976
Sudan Nzara 284 151 Esudan 1976
Dem. Rep. of Congo Tandala 1 1 Ezaire 1977
Sudan Nzara 34 22 Esudan 1979Gabon Mekouka 52 31 Ezaire 1994
Ivory Coast Tai Forest 1 0 EIvoryCoast 1994
Dem. Rep. of Congo Kikwit 315 250 Ezaire 1995
Gabon Mayibout 37 21 Ezaire 1996
Gabon Booue 60 45 Ezaire 1996South Africa
Johannesburg 2 1 Ezaire 1996
Uganda Gulu 425 224 Esudan 2000Gabon Libreville 65 53 Ezaire 2001Republic of Congo
Not specified 57 43 Ezaire 2001
Republic of Congo Mbomo 143 128 Ezaire 2002
Republic of Congo Mbomo 35 29 Ezaire 2003
Sudan Yambio 17 7 Esudan 2004
Dem. Rep. of Congo Luebo 264 187 Ezaire 2007
Uganda Bundibugyo 149 37 Ebundi 2007
Dem. Rep. of Congo Luebo 32 15 Ezaire 2008
VICTIM OF EBOLA ZAIRE
• The origin in nature and the natural history of Ebola virus remain a mystery
• It appears that the viruses are zoonotic.– that they are transmitted to
humans from discrete life cycles in animals or insects
Epidemiology
• The infection of human cases with Ebola virus through the handling of infected chimpanzees, gorillas, and forest antelopes – both dead and alive – has been documented in Côte d'Ivoire, the Republic of Congo and Gabon.
• The transmission of the Ebola Reston strain through the handling of cynomolgus monkeys has also been reported.
• person-to-person transmission is the means by which outbreaks and epidemics progress–direct contact with infected
blood, secretions, organs or semen
s
• Hospital-acquired infections have been frequent, and many health care workers have been infected while attending patients– In the 1976 Zairian Ebola epidemic,
many cases could be linked to the use of contaminated syringes and needles
• Transmission also occurs through preparation of the dead for burials
• lysogenic life cycle. This mean that the cycle does not immediately kill the infected host cells– The virus just invade the cells and
replicates or make more copies of it self and spread to other cells and destroy the host DNA
Life Cycle
• Ebola virus docks with cell membrane
• Viral RNA is released into the cytoplasm where it directs the production of new viral proteins and genetic material
• New viral genomes are rapidly coated in protein to create cores.–These viral cores stack up in the cell
and migrate to the cell surface
Life Cycle
• Transmembrane proteins are produced which are ferried to the cell surface.
• Cores push their way through the cell membrane becoming enveloped in cell membrane and collecting their transmembrane proteins as they do so
• The Ebola incubation period is the period of time between infection with the Ebola virus and the appearance of symptoms associated with the disease.
• incubation period can be as short as 2 days or as long as 21 days.
• After four to six days on average, symptoms of Ebola can begin
• Sudden onset of fever
• Intense weakness• Muscle pain• Headache • Sore throat
Symptomology
Then followed by:• Vomiting, diarrhoea, rash, impaired
kidney and liver function, and in some cases, both internal and external bleeding
• Laboratory findings show low counts of white blood cells and platelets as well as elevated liver enzymes.
EBOLA VICTIM
• CBC• ELECTROLYTES• Tests of how well the blood
clots (coagulation studies)• Tests to show whether
someone has been exposed to the Ebola virus
Tests
• a high fatality rate for this disorder (80% to 90%)
• mortality from Ebola has ranged from 25% to 90% and recovery is slow in those who survive.– Morbidity and mortality rates are
very high, and they vary with the strain of Ebola
Prognosis
• The most highly lethal Ebola subtype is EBO-Z, which has been reported to have a mortality rate as high as 88%.
• The EBO-S subtype has a reported mortality rate of 50%, similar to that of the Ebola outbreak in Gabon, where the mortality rate was 57-66%.
• There is no known cure for the disorder at this time
• For people with Ebola, treatment involves providing relief of Ebola symptoms while the body fights the infection.–Supportive Care–intravenous fluids, antibiotics, and
oxygen. Treatment may also include the use of medications to control fever, help the blood clot, and maintain blood pressure
Treatment
• DNA vaccines, adenovirus-based vaccines, and VSIV-based vaccines have entered clinical trials
Possibility of Vaccines?
• avoiding direct contact with the body fluid of infected people. Also, it's important to avoid direct contact with the body of an Ebola victim who has died
PREVENTION
• For healthcare workers in Africa, who are most likely to encounter cases of Ebola, prevention focuses on being able to recognize cases of the disease when they appear, as well as using barrier isolation techniques to avoid direct contact with infected people.
PREVENTION
Recommendations• Containment
– Those who are infected should be isolated in order to prevent further infection
• Make sure staff member should be informed about the nature of the disease in order to take proper precautions– Wear proper clothing to prevent
contamination
Proper Clothing
• Make sure linens or any material used by an Ebola patient should by cleaned thoroughly
• Ebola victims should be properly buried in order to prevent further infection
• Make sure the community and neighbouring communities are aware of the epidemic and inform them on safety precautions.
• Ban eating/hunting of animals that are most likely carriers of the virus such as gorillas.
• If you plan on travelling to uganda, DRC, Cote d’Ivoir and sudan check with the Center for Disease Control and Prevention before travelling to these places to make sure that there hasn't been an outbreak.
SLIGHTLY
• Using genetic particles known as small
interfering RNAs (siRNAs), scientists have
halted the replication process of the deadly
Ebola virus in monkeys
–a breakthrough that the researchers say
should be reproducible in humans.
–The study represents the first
demonstration of complete protection
against a lethal human infectious disease
in nonhuman primates using RNAi
31 May 2010
• In 6 December 2011 the development of a
successful vaccine against Ebola for mice
were reported. Unlike the predecessors it
can be freeze-dried and thus stored for long
periods in wait for an outbreak. The
research will be presented in Proceedings
of National Academy of Sciences
THE END?
Sources• http://www.medterms.com/script/main/art.a
sp?articlekey=6490• http://www.cdc.gov/ncidod/dvrd/spb/mnpag
es/dispages/ebola/ebolamap.htm• http://www.psmid.org.ph/vol25/vol25num1to
pic9.pdf• http://www.dailygalaxy.com/my_weblog/200
9/07/a-hot-zone-sequel-a-new-ebola-virus-detected-in-pigs.html
• http://www.rkm.com.au/virus/ebola/• http://www.virtualmedicalcentre.com/disease
s.asp?did=321#Prognosis
• http://www.scienceagogo.com/news/20100431010042data_trunc_sys.shtml
• http://health.nytimes.com/health/guides/disease/ebola-hemorrhagic-fever/overview.html