Describe general characteristic of Ebola
- Family: Filoviridae
- Structure
- (-) ssRNA
- Nonsegmented
- Helical
- Envelopep
- Replicate in cytoplasm
List 3 genuses of Filoviridae
- Ebola
- Marburg
- Cuevavirus
List 5 species of Ebola
- Zaire (current outbreak)
- Sudan
- Bundibugyo
- Tai Forest
- Reston (not infectious to humans – in the “Hot Zone”)
Which species of Ebola not infectious to human?
Reston
Describe the proteins coded by Ebola
7 structural proteins
2 non-structual proteins
Ebola Glycoprotein
- Part of viral envelope
- Secreted form
- Function: attachment/entry, pathogenicity
Ebola Matrix protein (2)
- VP40: important for structure, stability, assembly, budding
- VP24: assembly, budding, nucleocapsid assembly, immune defense
Which proteins form Nucleocapsid of Ebola? (2)
- VP 30
- Nucleoproteins
Which proteins function in Ebola replication? (2)
Polymerase comples - RNA-depedent RNApol
- VP35
- Large protein
Describe Ebola Pathogenicity (3)
- Enters body through mucosal surfaces or cuts to the skin
- Infect phagocytic cells –> release chemokines and cytokines –> attact more cells
- Travel to lymph nodes with phagocytes –> infect other organs
Describe the result of Ebola initial infection of phagocytes
Induces a massive cytokine storm –> desctory vascular endothelium, induce disseminated intravascular coaculation (DIC)
How do people die from Ebola?
People die from hypovolemia +/- organ failure
- When Ebola infects parenchymal cells, get significant cell destruction/necrosis
- With infection of endothelial cells, get leakage of fluids, severe fluid loss, hypovolemic shock, organ failure (hypovolemia and direct invasion)
How do Ebola evade host immune sytem through Glycoprotein? (surface-3 & secreted-1)
Glycoprotein (surface)
- Masks antibody binding sites
- Highly variable antigenic protein
- Physically blocks the MHC ability to stimulat immune response
Glycoprotein (secreted)
- Act as decoy for antibodies
What is the role of VP35 & VP24 in Ebola infection? (2)
Interfere cell’s interferon production
- Decreasing signal for help
- Prevent cell apoptosis
- Which organ is infected early on with Ebola?
- Why is this bad?
- Liver
- Inability to shut of cytokine storm
Ebola infection clincal symptoms? (4)
- Incubation: 2-21 days
- Fever, headache, weaknessm –> NOT specific
- Leaky vessels –> losing fluid daily
- NOT contagious until symptomatic
How do patients with Ebola lose fluid?
Through effluent - vomit, diarrhea
How Ebola pt being managed?
- Provide fluid repletion
- Dialysis, ventilation
- Isolation pt
Which body fluid contains Ebola virus only in Convalescent phase? (2)
- Semen
- Vaginal
Which body fluid containing Ebola virus span both phases (acute & convalescent phases)? (5)
- Blood
- Urine
- Tears
- Rectal/feces
- Milk
Which body fluid containing Ebola virus seen only in Acute phase? (2)
- Saliva
- Sweat
Potential drugs for Ebola [as of Feb. 2015]. (6)
- Favipiravir
- Brincidofovir
- Zmapp
- Tekmira’s TKM-Ebola
- Sarepta’s AVI-7537
- BioCryst BCX-4430
How does Favipiravir work?
nucleotide analogue for RNA
How does Brincidovovir work?
nucleotide analogue targets DNA viruses
