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 • Phospholipid• Cholesterol• Glycoprotein• Glycolipid

Ebola

• Identify• 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

• 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, & tiredness2. 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):• 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-actually-worry/ • http://www.ideastream.org/news/npr/342451672• http://www.huffingtonpost.com/2014/08/02/ebola-symptoms-infectio

n-virus_n_5639456.html • http://health.howstuffworks.com/diseases-conditions/infectious/ebola

9.htm • https://www.bcm.edu/departments/molecular-virology-and-microbiolo

gy/emerging-infections-and-biodefense/ebola-virus