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Flashcards in L83 Deck (40):
1

Flavi viruses: RNA or DNA?
Capsid spherical or icosohedral?
Released diseases

+ssRNA - "..flavored Coronas..."
Icosohedral capsid
4 diseases
1. Hep C
2. West Nile
3. Dengue fever + St. Louis
4. Yellow fever

2

Toga viruses: RNA or DNA?
Capsid spherical or icosohedral?
Released diseases

+ssRNA "I went to a retro toga party..."
Icosohedral capsid
Disease = chikungunya

3

Bunya viruses: RNA or DNA?
Capsid: helical, spherical, icosohedral?
Released diseases

-ssRNA "always Bring..."
Helical capsid
Hantavirus

4

Arena viruses: RNA or DNA?
Released diseases

-ssRNA "Always bring..."
Lassa

5

Filo viruses: RNA or DNA
Related disease

-ssRNA "always bring pol or Fail rep"
Ebola

6

What is common to all the zoonotic diseases?

All enveloped in lipid membrane - will break down in detergent
Aka main leaving mechanism is BUDDING

7

How do you diagnose all the zoonotic diseases?

Serology & PCR
Clinical picture isn't enough b/c non-specific symptoms

8

What is the common disease category for all of these viruses? What must be part of treating any pt with one of these diseases?

Viral hemorrhagic fevers
Pt isolation required!

9

Brazil
Ab pain + fever
Intractable vomiting
Abnormal coag, renal + liver failure
5 days after symptoms - died: shock, seizures, excessive bleeding at line sites
WHAT IS THE DISEASE?

Yellow fever

10

What virus causes yellow fever?

Flavi

11

What is the main organ target in yellow fever?

Liver --> hepatitis

12

How is yellow fever transmitted?

Mosquito
1. Urban - man to mosquito over and over
2. Jungle

13

You're worried about travelers from WHERE with yellow fever?

Brazil aka Amazon
Middle Africa around the equator

14

What are the 1ary, 2ary, and terminal symptoms of YF?

1 - fever + ab pain
2 - liver is failing = abnormal coag + black vomit
+ renal failure
Terminal - excessive bleeding, general shock

15

Diagnose YF

PCR for RNA

16

1: fever + headache + chills - bacteruria & hematuria
2: retro-orbital pain, worse when move eyes
↓WBC ANDDDD platelets!!
3: petechiae on LE
WHAT IS THE DISEASE?

Dengue

17

What virus causes Dengue Fever?

Flavi

18

You're worried about travelers from WHERE with Dengue Fever?

Caribbean - Key West
South America
Asia

19

What is Dengue Fever vs Dengue shock syndrome?

1st infection = DFever - mild, acute infection
2nd infection w/ different serotype (no Ab protect) = DSS, hemorrhagic fever & shock

20

Describe Dengue Fever pathogenesis

Mosquito bite
Infect DCs & monocytes
--> LN --> 1ary viremia
Develop immune response here - specific to the infecting serotype (no lasting immunity to other serotypes)

21

Describe 2nd infection of DF

Same serotype - Ab protection
Different serotype - DSS
- Abs try to bind new serotype --> ineffective
- Now these Abs are a "new binding site" for uptake of active virus into APCs
- Virus infects these APCs --> accelerated infection --> worse outcomes
Net: hemorrhage syndrome & shock

22

Does DF always present with petechiae?

No - can if there is hemorrhage in the 1ary infection

23

Acute fever for 1-3 wks
Followed by severe, debilitating joint pain lasting for months/years
WHAT IS THE DISEASE?

Chikungunya virus

24

Since Degnue and chikungunya viruses often co-circulate and present similar clinical pictures, how do you differentiate?

Dengue - thrombocytopenia & can have shock
Not in chikungunya

25

What viral family is chik in?

Toga

26

Describe chik pathogenesis

Mosquito bite
Local replication of virus at bite site --> LN
Moves to muscles and joints
Virus persists in muscle cells and macrophages for chronic infection
Immune system will clear infection - just a question of how long

27

What is the immune response for the acute phase vs chronic phase of chik?

Acute - Th1 response
Chronic - Th2 response

28

What type of immunity is the primary mediator of chik?

Ab

29

What viral family is hanta virus in?

Bunya

30

Hanta transmission

Rodents - deer mouse
- fecal-RESP through their droppings
"Sweeping out cabin with animal droppings"

31

What organ system symptoms are hallmarks of hanta?

Hanta pulmonary syndrome - SOB, respiratory distress

32

What virus family is lassa in? What is unique about the genome?

Arena
Lassa has 2 genetic RNA segments - each has specific polarity

33

Where are you worried about travelers and lassa fever?

West Africa

34

Lassa transmission

rats

35

Symptoms and disease of lassa fever

= Viral hemorrhagic fever
Fever/chills, sore throat, back pain

36

Who are you worried about dying from lassa fever?

Pregnant women (3rd trimester) & fetus

37

Treat lassa fever

Ribavirin

38

Describe how liver enzymes and platelets change during Ebola?

Liver enzymes - rise early, go VERY high late
Platelets plummet

39

Which of these infections can be transmitted back to the vector after a person has been infected?

Mosquito borne ones:
- YF
- Dengue
- Chik

40

In general, can you treat any of these with meds? Vaccinate?

Treat - no, all supportive
Vaccinate - only YF