L83 Flashcards
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
Toga viruses: RNA or DNA?
Capsid spherical or icosohedral?
Released diseases
+ssRNA “I went to a retro toga party…”
Icosohedral capsid
Disease = chikungunya
Bunya viruses: RNA or DNA?
Capsid: helical, spherical, icosohedral?
Released diseases
-ssRNA “always Bring…”
Helical capsid
Hantavirus
Arena viruses: RNA or DNA?
Released diseases
-ssRNA “Always bring…”
Lassa
Filo viruses: RNA or DNA
Related disease
-ssRNA “always bring pol or Fail rep”
Ebola
What is common to all the zoonotic diseases?
All enveloped in lipid membrane - will break down in detergent
Aka main leaving mechanism is BUDDING
How do you diagnose all the zoonotic diseases?
Serology & PCR
Clinical picture isn’t enough b/c non-specific symptoms
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!
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
What virus causes yellow fever?
Flavi
What is the main organ target in yellow fever?
Liver –> hepatitis
How is yellow fever transmitted?
Mosquito
- Urban - man to mosquito over and over
- Jungle
You’re worried about travelers from WHERE with yellow fever?
Brazil aka Amazon
Middle Africa around the equator
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
Diagnose YF
PCR for RNA
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
What virus causes Dengue Fever?
Flavi
You’re worried about travelers from WHERE with Dengue Fever?
Caribbean - Key West
South America
Asia
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
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)
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
Does DF always present with petechiae?
No - can if there is hemorrhage in the 1ary infection
Acute fever for 1-3 wks
Followed by severe, debilitating joint pain lasting for months/years
WHAT IS THE DISEASE?
Chikungunya virus
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
What viral family is chik in?
Toga
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
What is the immune response for the acute phase vs chronic phase of chik?
Acute - Th1 response
Chronic - Th2 response
What type of immunity is the primary mediator of chik?
Ab
What viral family is hanta virus in?
Bunya
Hanta transmission
Rodents - deer mouse
- fecal-RESP through their droppings
“Sweeping out cabin with animal droppings”
What organ system symptoms are hallmarks of hanta?
Hanta pulmonary syndrome - SOB, respiratory distress
What virus family is lassa in? What is unique about the genome?
Arena
Lassa has 2 genetic RNA segments - each has specific polarity
Where are you worried about travelers and lassa fever?
West Africa
Lassa transmission
rats
Symptoms and disease of lassa fever
= Viral hemorrhagic fever
Fever/chills, sore throat, back pain
Who are you worried about dying from lassa fever?
Pregnant women (3rd trimester) & fetus
Treat lassa fever
Ribavirin
Describe how liver enzymes and platelets change during Ebola?
Liver enzymes - rise early, go VERY high late
Platelets plummet
Which of these infections can be transmitted back to the vector after a person has been infected?
Mosquito borne ones:
- YF
- Dengue
- Chik
In general, can you treat any of these with meds? Vaccinate?
Treat - no, all supportive
Vaccinate - only YF
