DD- Virology of Ebola Flashcards Preview

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Flashcards in DD- Virology of Ebola Deck (40):
1

Ebola

rare and deadly disease caused by infection with a strain of Ebola virus.

2

Ebola causes

Hemorrhage from DIC

3

Filoviruses

encode their genome in the form of single-stranded negative-sense RNA.

2 members are Ebola virus and Marburg virus.

4

20% of people with ebola in recent outbreak are

health care workers

5

Ebola usually comes from

epizootic cycle

6

Ebola often is caused by ____ (animal)

fruit bat
(which can spread to other animals/humans)

7

Ebola outbreaks result from spillover events from animal reservoirs with subsequent ____________ transmission

human-to-human

8

Ebola Structure

Enveloped, negative-strand RNA, replicates in the cytoplasm

9

Ebola Enters body through:

mucosal surfaces or cuts to the skin

10

Ebola initially enters phagocytic cells, sends signal for more cells to come, which facilitates infecting those cells; also spreads efficiently when cells go to lymph nodes, which allows ebola to infect more _________

immune cells

11

After someone is infected with ebola, it is believed that he/she is________from future
infections; antibodies found out to 10 years after infection

protected

12

Antibody response to the surface glycoprotein on ebola is associated with ____

better survival

13

Ebola initially enters phagocytic cells, sends signal for more cells to come, which facilitates infecting those cells; also spreads efficiently when cells go to _______, which allows ebola to infect more immune cells

lymph nodes

14

Ebola has many ways to evade the human immune system

Glycoprotein (surface)
Glycoprotein (secreted)
VP35 and VP24

15

EBOLA:
Masks antibody binding sites/ highly variable/dispensible

Physically blocks the MHC and other cell surface proteins in order to block their role in triggering an immune response

Glycoprotein (surface)

16

Ebola initially enters ________, sends signal for more cells to come, which facilitates infecting those cells; also spreads efficiently when cells go to lymph nodes, which allows ebola to infect more immune cells

phagocytic cells

17

EBOLA:
secreted by the cell, act as decoys; antibodies against ______ aren’t very good at neutralizing the virus

Glycoprotein (secreted)

18

EBOLA:
both interfere with the cell’s interferon production, which plays a role in signaling for “help” and also inhibits the cell from apoptosis

VP35 and VP24

19

Initial cytokine release signaling for more immune cells to come to the area of initial infection, helps:______

ebola to spread

20

______ is the genetic material for Ebola

RNA

21

Found on viral envelope (also a secreted form)

Function: attachment and entry, key for pathogenicity

Glycoprotein = GP

22

Main part of virion/matrix, plays a role in virus structure, stability, assembly and budding

VP40:

23

Assembly, budding, nucleocapsid assembly, immune defense

VP24

24

Form the nucleocapsid (capsule around the genetic material/nucleus)

Nucleocapsid and nucleoprotein = VP30 and nucleoproteins

25

Ebola spead/infection

Only need a few virions for infection

Travels in immune cells (white cells) to regional lymph nodes where it replicates and spreads throughout the body

26

In the cell, ebola induces a massive:

“cytokine storm”

These molecules destroy vessel walls, also induce disseminated intravascular coagulation (DIC) - shock
Causes a dysregulated immune response

27

Get leakage of fluids and blood leading to severe fluid losses and possibly bleeding
Hypovolemic shock
Organ failure due to hypovolemia and/or direct destruction from virus

Effects of Ebola in vessel cell walls

28

People Die from ebola with________ +/- end-organ failure

hypovolemia

(Don’t die from hemorrhage)

Patients can lose 5-10 liters of fluid/day through “effluent” (vomit, diarrhea)

29

hypovolemia

state of decreased blood volume

30

These molecules destroy vessel walls, also induce disseminated intravascular coagulation (DIC) - shock
Causes a dysregulated immune response

“cytokine storm”

31

Effects of Ebola in vessel wall

Get leakage of fluids and blood leading to severe fluid losses and possibly bleeding
Hypovolemic shock
Organ failure due to hypovolemia and/or direct destruction from virus

32

Interfere with a cell’s signaling pathway that alerts immune cells that it’s infected

VP35 and VP24

33

EBOLA Incubation is _______days after exposure, but usually 6-10 days

– NOT contagious until symptomatic

2-21

34

monoclonal antibodies against 3 targets on GP

Zmapp
Drugs for Ebola

35

targets DNA viruses, nucleotide analogue, found to have in vitro efficacy against Ebola; a few of those treated in the US received it

Brincidovovir

Drugs being studied for ebola

36

under development in Japan for influenza, nucleotide analogue for RNA

Favipiravir

Drugs being studied for ebola

37

Ebola Rx
Management is symptomatic by

o Fluid repletion
o Electrolyte corrections
o Renal replacement, ventilation
o Need critical care
o Need to isolate patients

38

Symptoms of Ebola

GI, fever, fatigue/weakness; very similar to
other illness which are common (malaria, typhoid, dysentery)

39

After initial Ebola infection of phagocytes, then goes to infect many other cells/organs
in the body including:

endothelial cells
liver
spleen
lungs

40

EBOLA: Once in the cell, induces a massive cytokine storm –
cytokines and similar
molecules destory vascular endothelium, induce _________

disseminated intravascular coaculation (DIC)