Viruses

2. 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???

3. Identify • Phospholipid • Cholesterol • Glycoprotein • Glycolipid

4. Ebola • Identify • Phospholipid • Cholesterol • Glycoprotein • Glycolipid

6. 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

7. 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.

8. 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!!

9. 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

10. Images from: https://www.bcm.edu/departments/molecular-virology-and-microbiology/emerging-infections-and-biodefense/ebola-virus

12. Ebola symptoms • 2-21 day (typically 4-10) before symptoms start appearing • Fever, chill, headache, muscle and joint aches, & tiredness • Bloody diarrhea, severe sore throat, jaundice, vomiting & loss of appetite, low blood pressure….after about 5 days of thisrash can develop over torso • Massive bleeding is rare, but internal hemorrhaging (bleeding) is more likely…50%

13. 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

14. 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)

15. 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

17. 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?

18. 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 millionppl/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)

19. 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

20. 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-infection-virus_n_5639456.html • http://health.howstuffworks.com/diseases-conditions/infectious/ebola9.htm • https://www.bcm.edu/departments/molecular-virology-and-microbiology/emerging-infections-and-biodefense/ebola-virus