Viral Hemorrhagic Fever 87-88 Flashcards
VHF caused by 4 viral families
Flaviviridae, Bunyaviridae, Arenaviridae, Filoviridae
Transmission of VHF
Arthropod Vector, Rodent Excretions
VHF Clinicopathological features
Fever Hemorrhagic manifestations Thrombocytopenia Shock Neurological disturbances
VHF Signs and sxs
Fever Fatigue Dizziness Muscle aches Loss of strength Exhaustion
Serious VHF conditions
bleeding under skin
interal organs
body orifices
Sever Ill VHF
renal fail, shock nervous system coma delirium seizures
What does the virus infect?
Tissue macrophages
Dendritic Cells
VHF effect on dendritic cell
reduce costimulatory molecules
↓ immune responses
Hemorrhagic complications of VHF
Hepatic Damage
Consumptive coagulopathy
Thromboctopenia
Flavivirday
\+ RNA Enveloped glycoproteins Structural Non Structural coding regions NS1 antigen
Bunyaviridae
- RNA Enveloped Gn Gc proteins in envelope L segment M segment S segment
Arenaviridae
Ambisense ssRNA
Enveloped
Segmented
Filoviridae
- ssRNA
Filamentous
Pleomorphic
Enveloped
Types of Flaviviruses
West Nile
St Louis
Dengue
Yellow Fever
Dengue
4 serotypes
Dengue Host
Primate
But now humans by accident
Transmission of Dengue
Aedes mosquito — arbovirus
Clinical of Dengue
- DF
2. DHF
DF
acute infection high fever plus 2 of following headache eye pain joint pain muscle pain rash mild bleeding low WBC RESOLVES 2 WEEKS
DHF
infection from 2nd dengue Recurrent Fever Hemorrhgic manifestations positive tourniquet Thrombocytopenia Plasma leakage Pleural effusion
DHF Pathogenesis
Non-neutralizing abs promote uptake by 1. macrophages 2. Monocytes 3. Dendritic Cells Activate Tm cells, Effector T Cells release inflammatory vasoactive
Dengue Immunity
IgM 3-5 days
IgG shortly after
accumulation of complexes= tissue damage
NO CROSS IMMUNITY BETWEEN STRAINS
Yellow Fever Two Strains
Dakar
17D
yellow Fever Host & Vectors
Primate Humans (similar to Dengue) Mosquito (Vector) Aedes Haemagogus Sabethes
Yellow Fever Clinical
Biphasic Acute • fever • HA • LOA • shivers, skin flushing red eyes Toxic • return of fever • jaundice, GI Hemorrhage • Dissemination: Kidneys Heart, Vasculature