Arboviruses Flashcards
1
Q
Flavivirus and Togavirus
A
- minus rubella, all transmitted by insects
- establish viremia and target CNS and/or joints
- enveloped, positive-ssRNA
- capacity to infect wide variety of vertabarate and invertabrate hosts
- E (flavi) E2 (toga) glycoprotein cell attacment to GAGs moeities
- clathrin-mediated endocytosis
- low pH uncoating, E (flavi), E1 (toga)
- cytoplasmic assembly and ER budding
2
Q
West Nile
A
FLAVIVIRUS
Key:
- bird (crows) <–> mosquite bite -> human (dead-end host)
- elderly, immunocompro - aseptic encephalitis, meningits
- flaccid paralysis (neuron destruction)
- bird migration patterns
- no vaccine, no therapy
Extra:
- mosquitobite -> reticuloendothelial system -> secondary viremia -> CNA replication
3
Q
Dengue virus
A
FLAVIVIRUS
Key:
- mosquito bite
- DF (d. fever): breakbone fever, arthralgia, myalgia rarely fatal
- DHF (hemorrhagic): DF + thrombocytopenia, bleedin, shock, 10-40% mortality
- antibody depedent enhancement (previous Ab facilitate uptake of virus into macrophages) -> increased viral load
Extra:
- mosquite -> primary viremia -> reticuloendothelial replication -> secondary viremia (sustain transmission) -> replication in endothelium (muscles & synovium)
- no therapy
4
Q
Chikungunya virus
A
TOGAVIRUS
Key:
- fever, rash, arthritis
- caribbean current outbreak
- no treatments
Extra:
- current caribbean outbreak
- mosquite bite -> primary viremia -> reticuloendothelial replication -> secondary virema (sustain transmission) -> muscle and synovium replication
- africa, southeast asia
5
Q
Rubella virus (German Measles)
A
TOGAVIRUS
Key:
- *not arthropods (only human -> human), infected respiratory secretions
- febrile exanthem
- congenital - (placental transmission) first trimester: more severe CNS, second trimester: less severe
- live attenuated vaccine (MMR), no tx
Extra:
- aspiration -> respiratory replication -> primary viremia -> secondary reituloendothelial replication -> secondary viremia -> dissemination to conjunctive, skin, joints
