ebola discussion
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Transcript ebola discussion
Viruses
• Very small
• Nucleic Acids (DNA or RNA)
• Some have phospholipid bilayer
• Protein Coat covering Nucleic Acids
• Receptors in protein coat
• Cannot self-replicate……so are they alive???
• Identify
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Phospholipid
Cholesterol
Glycoprotein
Glycolipid
Ebola
• Identify
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Phospholipid
Cholesterol
Glycoprotein
Glycolipid
Ebola: How does it work??
• RNA, not DNA
• Filovirus
• Long branched/hooked and thin (their length is about 1/16 the width of hair)
• Only 19,000 base pairs….humans have 3 billion!!!
• RNA codes for 7 proteins (humans:~20,000)
• Glycoprotein2 versions: one host cell, one released from infected cells &
may play a role in suppressing the immune system
Microbiology behind it…
• Glycoprotein attaches to glycoprotein on a human cell membrane.
• Wide range of cells (starts with immune system cells lymph nodes, spleen &
liver through the blood)
• Endocytosis (engulfs the ebola virus capsule)
• Once cells attacked triggers the release of different chemicals which cause
the symptoms of the disease.
Microbiology behind it….
• Viral membrane fuses with vesicles and
releases the nucleocapsid (small “capsule”
with the RNA) into the cytoplasm
• The virus then uses the host’s ribosomes to make all of it’s proteins.
• Viral proteins are then processed and released from cell once that level is high
enough in the host, ebola starts to replicate the new RNA wrapped up all
those proteins (encapsulating it)
• New virus in it’s new capsule travel to cell membrane wraps itself up
in a nice “blanket” of the host cell’s membrane!!
Microbiology behind it……
• The Ebola proteins (made and released from the host cell) leave
infected cell bind to receptors on the inside of the blood vessels
increases permeability of blood vessels causing leaky veins
shock and/or death
• Master at avoiding the immune systemblocks the signal to the
body’s “alarm system” not until cells begin to burt is the immune
system triggered and then it “freaks out” fever & flu-like symptoms
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Images from: https://www.bcm.edu/departments/molecular-virology-and-microbiology/emerging-infections-and-biodefense/ebola-virus
Ebola symptoms
• 2-21 day (typically 4-10) before symptoms start appearing
1. Fever, chill, headache, muscle and joint aches, & tiredness
2. Bloody diarrhea, severe sore throat, jaundice, vomiting & loss of
appetite, low blood pressure….after about 5 days of thisrash can
develop over torso
3. Massive bleeding is rare, but internal hemorrhaging (bleeding) is
more likely…50%
How contagious is it?
• Currently under debate….
• Past occurrences all documentation says only by coming into direct contact
with bodily fluids of an infected person
• Current occurrences under debate because it looks like in some cases it is
air borne (ape study)…..intentional or evolution?
• past occurrences said only contagious when ebola symptoms present
• Current situation trying to figure out timeline of it all is difficult, but it
looks like a person can be contagious before they show symptoms
How contagious is it?
• Can animals have it?
• Don’t really know where Ebola lives most of the time
• Fruit bats thought to be main reservoir of ebola in nature, but they are by no
means the only animals that carry it
• Dogs/cats? (TX man’s dog controversy) no evidence to date, but then
again…there’s just not much evidence period…..
• So far known transmissions are gorillas, chimps & Duiker (a small weird deer
in Africa)
Is it fatal
• About 50% (25-90%) mortality rate.
• Depends on how quickly it’s caught (if we can catch it before our body
realizes it, we can attack it and kill it before our body “freaks out”)
• Depends on how it is transmitted. Dirty needles…odds not so good,
close contact….a little better
Is there a cure?
• Not yet, not for humans
• Success with one ape test
• Tricky at least 416 health care workers have contracted
Ebola, and at least 233 have died…
• Two possibilities are currently being tested on humans
• Skipped a bunch of rules & regs and started testing on humans last
month….results/success pending
• Ethical?
• Possible side effects & outbreaks?
How worried should I be?
• For now, not much. It’s not in the area.
• Put it in perspective (all USA data):
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Ebola 2 confirmed cases (84,000 in Africa)
ENTEROVIRUS (remember from a few months ago?) 10-15 million ppl/year
Whooping Cough 48,277 in 2012
Drug resistant bacteria 2 million ppl/year 23,000 ppl/year (die)
Flu & Pneumonia 2010 53,000 ppl died, millions catch it a year…..and
there’s a vaccine (ppl just chose not to get it)
Issues….
• Why do we know so little?? not common + extremely deadly = not many
volunteers and funding to research it…
• Airport screenings (planes reroutes for people with a fever)
• Airport traveling (should we allow people from infected countries in our
borders?)
• Euthanization of pets from affected people
• Africa
• Health care
• Myth & methods
resources
• WHO http://www.who.int/mediacentre/factsheets/fs103/en/
• PBS http://www.pbs.org/newshour/updates/six-diseases-actuallyworry/
• http://www.ideastream.org/news/npr/342451672
• http://www.huffingtonpost.com/2014/08/02/ebola-symptomsinfection-virus_n_5639456.html
• http://health.howstuffworks.com/diseasesconditions/infectious/ebola9.htm
• https://www.bcm.edu/departments/molecular-virology-andmicrobiology/emerging-infections-and-biodefense/ebola-virus