L1: Viral Hemorrhagic Fevers Flashcards
Case Presentation of VHF
DDx of VHF
Def of VHF
Different Famelies of VHF
Survival dependent on an animal or insect host, for the natural reservoir
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Site of Filoviridae
Case Fatality of Filoviridae
Agents of Filoviridae
Site of Arenaviridae
Agents of Arenaviridae
Case Fatality of Arenaviridae
Site of Bunyaviridae
Agent of Bunyaviridae
Case Fatality of Bunyaviridae
Site of Flaviviridae
Agents of Flaviviridae
Case Fatality of Flaviviridae
Genome of VHF
All are single-stranded RNA.
Structure of VHF
All are enveloped (transmission by foods or drinks???)
Infectivity of VHF
- Infectious during viremia stage.
- Low infectivity dose (1-10 viruses can cause infections).
Reservoir of VHF
Humans are not the natural reservoir but accidentally infected when comes in contact with infected hosts.
Outbreaks of VHF
Human outbreaks are sporadic and irregular.
Infectivity of Humans in VHF
Human infected can infect another human
Type of VHF
- VHFs are zoonosis: Animal hosts (Rodents) and arthropod vectors are main reservoirs.
MOT of VHF
- Bite of infected arthropod (ticks or mosquitos)
- Aerosol from infected rodent excreta
- Direct contact with infected animals / carcasses or fomites
Pathogenesis of VHF
Target organ of VHF
The target organ is the vascular bed (hemorrhage)
Replication of VHF
The replication of virus is intracellularly
What do VHF release?
Cytokine release leads to shock and hypotension.
What do cytokines of VHF cause?
- Affects Platelet functions and numbers (thrombocytopenia)
- Affects bone marrow and clotting factors.
CP of VHF
Initial Symptoms of VHF
 Marked fever
Fatigue
 Dizziness
Muscle aches
 Exhaustion
More severe symptoms of VHF
 Bleeding under skin ( Petechiae, ecchymosis, conjunctivitis )
 Bleeding in internal organs
 Bleeding from orifices
Blood loss rarely cause of death