Viral hemorrhagic fever Flashcards
Name the 3 types of viral hemorrhagic fever
Rodent-associated
Bat-associated
Arthropod-borne
Which viral hemorrhagic fevers are transmitted by mosquitoes?
Yellow fever
Rift valley fever
Which viral hemorrhagic fevers are transmitted by ticks?
Crimean congo fever
Which viral hemorrhagic fevers are transmitted by rodents?
Lassa fever
Lujo fever
Which viral hemorrhagic fevers are transmitted by bats?
Ebola
Marburg
What are viral hemorrhagic fevers?
ssRNA viruses (easily killed by bleach)
Are all viral hemorrhagic fevers notifiable conditions?
Yes! By law!
Which VHFs have a vaccine?
Yellow fever
Rift valley fever (animals)
Which VHFs have treatment?
Lassa fever
CCHF
What is the differential diagnosis for VHF?
Bacterial septicemia
Rickettsia
Spirochete (leptospirosis)
Parasitic (malaria)
Viral (hepatitis)
Non-infective (drug reactions, snake bite)
What are the 4 genera of filoviridae?
- Marburgvirus
- Dianlovirus
- Cuevavirus
- Ebola virus
What are the 2 strains of Marburgvirus?
MARV (Uganda)
RAVN/RAAV (Kenya)
What is the species of dianlovirus?
Mengla virus
Which 2 viruses is mengla virus like phylogenetically?
Between Ebola and Marburg
Is the actual disease-causing capability of menglavirus known?
No
New, from China, potential to be severe
What are the species in cuevavirus?
Lloviu (LLOV) from Spain, France, Portugal
Are cuevavirus pathogenic?
Only to bats
No human cases described
What are the species of Ebolavirus?
Bundibugya (BDBV)
Sudan (SUDV)
Tai forest (TAFV)
Ebola (EBOV)
How is ebolavirus transmitted?
Direct contact with human bodily fluids during acute illness
Describe the pathogenesis of ebolavirus
- Initial infection of MPS in regional lymph nodes
- Replication, suppression of INF and rapid dissemination
- Large cytokine and chemokine release
- Endothelial permeability, macromolecular leakage, tissue destruction -> coagulopathy and hepatic dysfunction
How are coagulation defects induced in ebolavirus infection?
Indirectly through host immune response
What happens to platelets during filovirus infection?
Filovirus directly infect and destroy megakaryocytes
What criteria is required to define ebola?
- Travel from affected area <21d
- Exposure to bodily fluids
- Fever
- Symptoms
- Decreased platelets
- Increased LFTs
What are the 2 ebola vaccines?
Ervebo
Zabdeno and Mvabea
How is lassa fever transmitted?
Direct contact with infected rodents or aerosols
What is the incubation period of lassa fever?
3-16 days
What is treatment of lassa fever?
Ribavirin
MUST (max use of supportive therapy)
How is CCHF transmitted?
Tick bites or direct contact with infected blood/tissue
What is the incubation period of CCHF?
Tick (1-3d)
Blood/tissue (5-6d)
What is treatment of CCHF?
Ribavirin
MUST
What must you ALWAYS consider in acute febrile illness in young patients?
Meningococcemia
Which virus is associated with “green monkey fever”
Marburg virus
Which bats are a resevoir for marburgvirus?
Rousettus aegyptiacus
What tests can be done for marburgvirus?
Blood/saliva PCR
Serology
How do you treat marburgvirus?
Monoclonal antibodies
Is there a vaccine for marburgvirus?
Not technically
Mvaboa vaccine produces 4 glycoproteins (zaira ebola, sudan, tai forest and marburg) but unproven
How is dengue fever transmitted?
Aedes aegypti
Aedes albopictus
What is the clinical presentation of dengue according to WHO classification?
Dengue w/o warning signs
Dengue w/ warning signs
Severe dengue
When is dengue fever highest risk for severity?
> 18 months apart from 1st infection
What is the incubation of dengue fever?
3-14d
What are the disease phases of dengue fever?
- Febrile
- Critical
- Recovery
What clinical test can be done for dengue?
Tourniquet test
What are the clinical markers in dengue fever?
Low platelets
Low white cells
Elevated AST
Synthetic liver dysfunction
What are the 2 licensed dengue vaccines?
Dervaxia
TAC-003 (QDENGA)
What is the backbone of Dervaxia?
Yellow fever
What is the backbone of QDENGA?
DENV-2
Which vaccine does not require previous dengue exposure?
QDENGA
