Vnu – hanoi university of sciences
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Transcript of Vnu – hanoi university of sciences
VNU – Hanoi University of sciences
Faculty: Environmental scienceSubject: Biology L111. evolution and diversityTeacher: Asso. Prof. Thuy Tran VanClass: K57TTKHMT
Content
- General information- What is Ebola virus?- How does Ebola virus spread?- How do we adapt with Ebola virus?
-Pham Thi Minh Huyen- Le Thi Van Anh- Ho Nguyen Hoang- Duong Nhat Khanh
Nearly 40 years ago, a young Belgian scientist travelled to a remote part of the Congolese rainforest - his task was to help find out why so many people were dying from an unknown and terrifying disease. In September 1976, a package containing a shiny, blue thermos flask arrived at the Institute of Tropical Medicine in Antwerp, Belgium. Working in the lab that day was Peter Piot, a 27-year-old scientist and medical school graduate training as a clinical microbiologist. "It was just a normal flask like any other you would use to keep coffee warm, " recalls Piot, now Director of the London School of Hygiene and Tropical Medicine. But this thermos wasn't carrying coffee - inside was an altogether different cargo. Nestled amongst a few melting ice cubes were vials of blood along with a note. It was from a Belgian doctor based in what was then Zaire, now the Democratic Republic of Congo - his handwritten message explained that the blood was that of a nun, also from Belgium, who had fallen ill with a mysterious illness which he couldn't identify.
It is the river where hide the secret about one danger epidemic
An old story
In this first Ebola epidemics, 318 people were infected, of which 280 people died in Congo and 284 cases, 151 deaths in a region of Sudan. It means that the mortality rate of the disease up to 90 percent (10 were infected => 9 were death).
These were the three questions Piot and his colleagues asked:
1. How did the epidemic evolve? Knowing when each personcaught the virus gave clues to what kind of infection this was - from here the story of the virus began to emerge.
2. Where did the infected people come from? The team visited all the surrounding villages and mapped out the number of infections - it was clear that the outbreak was closely related to areas served by the local hospital.
3. Who gets infected? The team found that more women than men caught the disease and particularly women between 18 and 30 years old - it turned out that many of the women in this age group were pregnant and many had attended an antenatal clinic at the hospital.
The mystery of the virus was beginning to unravel. The team then discovered thatthe women who attended the antenatal clinic all received a routine injection. Each morning, just five syringes would be distributed, the needles would be
reused and so the virus was spread between the patients.
And the virus can be transmitted by skin because protective gears are incomplete,...
The recent Ebola outbreak that started in March 2014, however, has reached epidemic proportions and has killed more than 6000 persons as of December 2014.
This outbreak has been centered in West Africa, an area that had not previously been affected by the disease. The toll has been particularly grave in three countries:
Guinea, Liberia, and Sierra Leone.
Figures accurate from 4-6 October, depending on country. Death toll in Liberia includes probable, suspect and confirmed cases, while in Sierra Leone and Guinea only confirmed cases are shown
In the absence of any vaccine or cure, the advice for this outbreak is much the same as it was in the 1970s. "Soap, gloves, isolating patients, not reusing needles and quarantining the contacts of those who are ill - in theory it should be very easy to contain Ebola," says Piot.
What is symptoms of Ebola disease?
• According to WHO, sudden fever, stress, muscle pain, headache and sore throat are typical symptoms of Ebola virus disease known.
• This was followed by vomiting, diarrhea, rash, renal dysfunction and liver, and in some cases bleeding both inside and outside (Ebola can cause bleeding from the eyes,
ears, nose , mouth and rectum).• The incubation period of the disease Ebola virus ranges from 2 to 21 days after
exposure to the pathogen until the first symptoms. • Results of laboratory studies showed that blood cell and platelet counts are low Ebola
virus infections while higher than normal liver enzymes. • According to WHO, the patient will be contagious to other
people when they start having symptoms. During the incubation period, they are not likely to spread.
Definition - Ebola is a viral illness of which the initial
symptoms can include a sudden fever, intense weakness, muscle pain and a sore throat, And that is just the beginning: subsequent stages are vomiting, diarrhoea and - in some cases - both internal and external bleeding. (according to the World Health Organization (WHO).
- Subtype: Zaire, Sudan, Reston, and Côte d'Ivoire (Ivory Coast)
Structure Rod-shape or 6-shape Virion: filamentous, 970 nm long, 80 nm in
diameter, enveloped Genome: approximately 19 kilobase
negative-sense, single-stranded RNA Proteome: 7 sequentially arranged
proteins Infection: initiates by the attachment of GP
glycoprotein to host receptors RNA Transcript: 5' methyl cap, 3' poly-A
tail
Genome of Ebola virus RNA Transcript: 5' methyl cap, 3'
poly-A tail3-leader-NP-VP35-VP40-GP/
sGP-VP30-VP24-L-- trailer-5'
Natural Ebola virus hosts: fruit bats of the Pteropodidae family
Ebola is introduced into the human population: through close contact with the blood, secretions, organs or other bodily fluids of infected animals (chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest)
Transmission from wild animals
Direct contact : through broken skin or mucous membranes, with the blood, secretions, organs or other bodily fluids of infected people.
Indirect contact: with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.
Human-to-human transmission
Binding and entry of an infecting virion virus protein expression + RNA replication assembly and release new virion
The viral life cycle
Through contact with mucous membranes or through skin breaks
infection : endothelial cells( tb nội mô) , liver cells ( tb
gan), and several types of immune cells ( tb miễn dịch)
such as macrophages, (đại thực bào) monocytes,( bạch cầu
đơn nhân) and dendritic cells ( tb đuôi gai) lymph nodes(hạch bạch huyết) bloodstream and lymphatic system ( hệ thống bạch
huyết) throughout the body programmed cell death. low concentration of lymphocytes in the blood the weakened immune
Inside human body
As viruses replicate, their genome changes. EPA/Ahmed Jallanzo
The Broad Institute/Harvard University study
In order to better understand the origin and transmission of the current outbreak in West Africa
in collaboration with the Sierra Leone Ministry of Health, sequenced 99 virus genomes from 78 patients.
How does Ebola evolve?
Researching about early and late in the outbreak how genetic changes ( which make virus easier to spread) manage future outbreaks
How does Ebola evolve?
Ebola fears prevent the world from developing
So far, no vaccine or cure is available. Due to the current problems, finding the
ways out is very important. For everyone, just protect yourself by doing
the rules above.
Conclusion:
BBC NEWS Wiki.org The conversation - http://theconversation.com/genetic-
evolution-how-the-ebola-virus-changes-and-adapts-31525 Els Article - http://www.els.net/WileyCDA/ElsArticle/refId-
a0001022.html BBC World Service Sciencemag - http://www.sciencemag.org/site/extra/ebola/ https://flipboard.com/section/plos-ebola-collection-bRVgYj http://www.ncbi.nlm.nih.gov/genome/viruses/variation/ebol
a/ http://www.viprbrc.org/brc/home.spg?decorator=filo_ebola David M. Knipe, Peter M. Howley, et al.. Fields’ Virology. 5th
edition. 2007 Lippincott Williams & Wilkins. USA, http://www.cdc.gov/vhf/ebola/
References