Brainscape's Knowledge GenomeTM

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


See full index

Virology > Arboviruses > Flashcards

Arboviruses Flashcards

1
Q

Classification of West Nile Virus

A

Flavivirus

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

When was it first discovered in N. America and when does it seasonally peak

A

1999 discovered AND peaks usually in late summer/fall each year

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

What are the vectors and hosts for WNV

A

culex mosquitos and many types of birds.

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

How has transmission occurred?

A

Usually arthropod although some human-to-human via blood transfusions, organ transplants, transplacental psread, breast milk, and sometimes… percutaneous occupational exposure.

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

What % of WNV infections are asymptomatic?

A

75% are asymptomatic

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

What % of infections lead to neuroinvasive disease

A

1%

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

Describe the clinical sx of WNV

A
  1. fever
  2. headache
  3. backache muscle aches
  4. vomiting (may lead to dehydration)
  5. diarrhea
  6. loss of appetite
    Transient macular rash may occur
    This is called West Nile Fever. Often followed by persistent fatigue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How long does this West Nile Fever usually last

A

3-6 days

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

What is the outcome of neuroinvasive diasease

A

meningitis, encephalitis, polio-like paralysis… death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Who is at risk

A

the elderly (>50), immunodeficiency. 10% mortality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you dx WNV

A

IgM detection in serum for acute disease. retrospectively by looking for >4x increase in IgG

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

Prevention of WNV?

A

draining water

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

Classification of Eastern Equine Encephalitis? How many cases each year in US

A

alphavirus - single stranded RNA. only 5-15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Who is at risk of EEE? death rate? Long-term

A

young children and elderly. 50-70% death rate. Long-term = seizures, spastic paralysis, personality changes, and mental retardation

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

What makes it different from WNV?

A

transmitted by a different mosquito species AND is maintained in birds in the fresh water swamps of gulf of mexico and atlantic states

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

Where is Western Equine Encephalitis found and classification

A

alphavirus. Found in Western plains of the US, canada, and South America. Similar to EEEV, BUT it only causes CFR of 3-10%

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

Distribution and classification of St. Louis Encephalitis

A

flavivirus, distributed throughout western hermisphere

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

Mosquito vector

A

culex mosquito… just like WNV

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

At risk AND CFR?

A

persons >60 are at risk. CFR is 22%

20
Q

Classification of Dengue? # of serotypes?

A

Also a flavivirus. there are 4 serotypes - each provide specific lifetime immunity and short-term cross-immunity

21
Q

How many infections occur each year? how many are hemorrhagic

A

Dengue is the most common arbovirus in the world with 100 million infections annually. about 500,000 are hemorrhagic

22
Q

Describe pathogenesis of dengue.

A

DENV will replicate locally and in lymph nodes. Within 2-3 days it will spread to the blodo and makes its way to various tissues including the skin.

23
Q

When do sx start?

A

2-3 days after infection correlating with viremia, replication in certain tissues (like muscle), and cytokine release

24
Q

What is dengue shock syndrome (DSS)?

A

After sudden extravasation of plasma into the extravascular sites including the pleural and abdominal cavities. This leads to intense immune activation and formation of immune complexes that will activate complement.

25
Q

Who is at risk of DSS

A

those with pre-existing partial anti-dengue immunity. Heterologous antibodies may enhance viral uptake and replication. This is called ANTIBODY-DEPENDENT ENHANCEMENT.

26
Q

What is the dengue vector. What time do they bite?

A

Aedes aegypti mosquito. Female. daytime feeders

27
Q

What are the 4 fates of dengue clinically?

A
  1. Undifferentiated fever (most common manifestation)
  2. classic dengue fever
  3. dengue hemorrhagic fever
  4. dengue shock syndrome
28
Q

What is dengue fever?

A

fever, headache, muscle and joint pain (“break bone fever”), nausea/vomiting

29
Q

What are the hemorrhagic manifestations?

A

skin hemorrhages (petechiae), gum bleeding, nasal bleeding, gastro-intestinal bleeding, hematuria (blood in urine), increased menstrual flow

30
Q

What are labs associated with dengue hemorrhagic fever?

A 
1. low platelet count (<100,000)
leaky capillaries evidence:
2. elevated hematocrit
3. low albumin
4. pleural or other effusions
31
Q

What are the 4 clinical criteria for dengue shock syndrome

A
  1. rapid, weak pulse
  2. hypotension
  3. cold/clammy skin
  4. altered mental status
32
Q

How does one lab test for dengue?

A
  1. viral detection by RNA PCR
  2. ELISA for nonstructural protein 1
  3. virus isolation
  4. IgM antibody test for serologic diagnosis
  5. 4-fold rise in IgG antibodies for chronic infections
33
Q

Classification of yellow fever and where did it come from slash where is it found?

A

flavivirus that came from Old-World. Now it is found in tropical areas of sub-Saharan Africa and South America

34
Q

What is the vector

A

Aedes

35
Q

What are the only two major arboviruses where humans are the major vertebrate host

A

dengue and yellow fever

36
Q

How many YF deaths per year and where?

A

30,000 deaths (just like dengue) and 90% in africa

37
Q

how long is the incubation period

A

3-6 days.

38
Q

Describe the unique acute period

A

after incubation, there are 3 days of viremia with flu-like symptoms, then there is 1 day of defervescence and improvement (24 hrs) and then it all returns with vomiting epigastric pain, prostration, jaundice.

39
Q

What happens in severe disease?

A

It can progress to hemorrhagic phase in a minority of cases. you see the following:
petechiae, ecchymoses, melena. intravascular volume depletion. Renal failure
decreased urine output and increased albuminuria (albumin in urine)

40
Q

What is the vaccine like?

A

95% effective. It is a live attenuated vaccine. need a new one every 10 years

41
Q

What classification is chikunguya (CKV)?

A

alphavirus

42
Q

What happened to CKV spread and what is its vector

A

it spread from africa to indian subcontinent and asia. What let it do this was a change that allowed it to utilize vector of A. aegypti to A. albopictus.

43
Q

Describe chikunguya acute sx.

A

severe polyarthralgias, arthritis, rash, fever, headache, GI sx

44
Q

what are hallmark lab findings

A

lymphopenia, hypocalcemia, thrombocytopenia

45
Q

How is dx made

A

IgM antibody or virus detection. confirmed by IgG rise in convalescent serum

46
Q

What are the long-term sequelae

A

arthralgias and arthritis may persist for months (70% past 2 months and 13% past 6 months)

Virology (9 decks)

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