ebola discussion

• 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
• Identify
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)
• Glycoprotein2 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 systemblocks 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
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 thisrash 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):
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)
• 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
• Euthanization of pets from affected people
• Africa
• Health care
• Myth & methods
• 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

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