Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Infection and Immunity > Viral Haemorrhagic Fevers > Flashcards

Viral Haemorrhagic Fevers Flashcards

1
Q

What can happen in Viral Haemorrhagic fevers (VHF)?

A

Severe multisystem syndrome
Damage to the vascular system
Haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the disease spectrum for viral haemorrhagic fever?

A

Mild illnesses

Fatal (roughly 90% cases)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Who is the primary host for VHFs?

A

Humans not primary host
Range of viruses associated with VHFs
Relatively rare worldwide & not usually found in Scotland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some examples of VHFs in Glasgow?

A 
Crimean-Congo haemorrhagic fever virus (2012)
Ebola virus (2014 & 2015)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are common features of VHFs?

A

Enveloped RNA viruses
Animal or insect hosts
Sporadic human outbreaks
Generally no effective vaccine or antivirals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is required as a host for VHFs?

A

Natural reservoir
Arboviruses
Geographically restricted: determined by host species range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do human outbreaks occur with VHFs?

A

Due to contact with host species
Can be transmitted between humans
Cannot be predicted
Seasonality (rainy/warmer/trees fruiting)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the only VHFs with a vaccine?

A

Yellow fever virus vaccine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are examples of Arenaviridae?

A 
Lassa
Machupo
Junin
Guanarito
Sabia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some examples of Bunyaviridae?

A 
Hantaan
Crimean-congo
Rift valley fever
SFTSV
Heartland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some examples of Flaviviridae?

A

Dengue (DHF)
Yellow fever (YF)
Chikungya (CHF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some examples of filoviridae?

A

Ebola (EHF)

Marburg (MHF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the Ebola virus?

A 
Filoviridae
Filo- thread like
Ebola- river in DRC
Filamentous, plemorpic particles
Can be stained and viewed in patients blood by electron microscopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the filovirus outer structure?

A

Outer envelope has glycoproteins (GP) on surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the outer envelope of the filovirus surround?

A

A matrix containing the nucleocapsid (NP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is genomic RNA encapsilated by in the filovirus?

A

NP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do regulatory regions do in filovirus?

A

Flank the coding regions (7 genes)
Nucleoproteins (NP & VP30)
Polymerase complex (VP35 & L)
Membrane associated proteins (GP, VP40 & VP24)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are viral proteins translated from?

A

Subgenomic messenger RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is filovirus subgenomic mRNA transcription?

A

L protein binds at 3’ end
Subgenomic mRNA generated from transcription start signals
Terminates at stop signal
Polymerase releases at stop and reinitiates
mRNA capped and Poly (A)d
Transcriptional gradient of mRNA levels 3’ to 5’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the filovirus replication cycle?

A

Receptor binding
Genome transcribed & replicated in cytoplasm
Viral proteins translated
Proteins and negative strand genome packaged into particles
Virus buds from the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When does acute onset of Ebola occur?

A

2-21 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the symptoms of acute onset of Ebola?

A

Fever, chills, myalgia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are then the further symptoms of ebola?

A

Vomiting, abdominal pain, diarrhoea, chest pain, wheezing, headache, confusion, coma
Haemorrhage
Shock and convulsions (roughly 50% cases)

24
Q

Where is the natural host reservoir for Ebola?

A

Fruit bats
Direct contact with infected animals
Fruit bats thought to infect primates

25
Q

How did humans get Ebola?

A

Transmission from pigs to non-human primates

26
Q

Where do localised outbreaks of Ebola continue to occur?

A

Central and West Africa

27
Q

What are the number of infections in central and west africa?

A

1900

28
Q

How many deaths have there been in central and west africa?

A

1300 deaths pre 2013

29
Q

How many deaths were there between 2013-2016?

A

> 12,000 deaths

30
Q

What could see the spread of Ebola?

A

Global warming, increased air travel

31
Q

What do more outbreaks of Ebola increase?

A

The potential for bioterrorism

32
Q

What is required urgently for Ebola?

A

Effective and safe vaccine

33
Q

What is the ebola vaccine using glycoprotein gene?

A

Trialled in the UK- 72 participants
Phase 1 clinical trial vaccine/Placebo
Protected monkeys- Zaire

34
Q

What is the ebola vaccine using GSK (Adenovirus+ Zaire & Sudan)

A

Trialled in the USA- 20 participants

Antibodies produced, well tolerated and seems effective

35
Q

What work is being done for a vaccine in the national microbiology lab, Canada?

A

Phase one trial, called VSV-ZEBOV (Vesicular stomatitis virus)
Volunteers reported joint pain
Resumed the trial- lower dose of vaccine
VSV-EBOV one gene of VSV has been replaced with GP of Zaire EBOV

36
Q

What is Yellow fever?

A

Liver disease
Jaundice a major symptom
Hence the name
1st human virus 1901

37
Q

What is acute infection of yellow fever?

A

3-6 days incubation
Death in 20-50% of severe cases
After 7-10 days of illness

38
Q

What is Dengue?

A

Dengue haemorrhagic fever

Fatality rates 1-10%

39
Q

What is both Yellow fever and dengue?

A

Arboviruses

40
Q

How can human to human transmission occur in HF?

A

Mosquito (YF)

Blood/needles (Ebola)

41
Q

What is the flavivirus genome organisation?

A

Positive sense RNA genome
10kb in length
Transcribed then translated into a glycoprotein that is cleaved by viral proteases
Structual genes 5’ end & NS 3’

42
Q

How did Yellow fever (YF) and mosquito vector spread to the US?

A

Via shipping

43
Q

What were the original fatalities in the US due to YF?

A

15% in Philidelphia (1793)

28% in New Orleans (1853)

44
Q

Who discovered mosquitoes caused YF?

A

Carlos Finlay and Walter reed (1880-1900)

45
Q

What vaccine was developed for yellow fever and when?

A

17D vaccine developed in 1937

46
Q

How many deaths were due to yellow fever?

A

> 10,000 deaths pa ww

47
Q

What is the Yellow fever vaccine?

A

Live attenuated yellow fever vaccine (mutations in E)
Grown in infected chicken embryos
95% protection, 10 days p.i.
Life-long immunity

48
Q

What is the safety of yellow fever vaccine?

A

Very few side effects (allergic reactions & some reports of neurological complications, 1 in 1,000,000)

49
Q

What can not be infected orally with 17D?

A

Ae. Aegypti

50
Q

Why can’t Ae. Aegypti be infected orally?

A

No natural transmission of vaccine virus

No chance of reversion to virulence

51
Q

What is dengue haemorrhagic fever (DHF) vector controls?

A

Aedes aegypti- mosquito host for dengue and yellow fever
Vector control measures collapse in 70s/80s
Mosquito reinvades
Emergence of epidemic dengue and dengue haemorrhagic fever
Increased in yellow fever

52
Q

Where does dengue occur?

A

Asia, Afria and the Americans

53
Q

Where does yellow fever not occur?

A

Asia

54
Q

What are some of the ecological changes that are risk factors in contracting a VHFs?

A

Travel- globalisation
Urbanisation- changing vector habitats or moving humans into new areas
Environmental manipulation- Dam building

55
Q

What are some large scale changes in virus ecology introduced by humans?

A 
Air conditioning 
Blood transfusion 
Xenotransplantation 
Long distance movement of animals
Sexual practices 
Drug use
Irrigation
Deforestation 
Used tires
Uncontrolled urbanisation 
Day care centres
Cruise ships
Rerouting of migratory patterns

Infection and Immunity (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions