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13 Cards in this Set
- Front
- Back
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What is diff between 'respiratory droplets' and 'true aerosol'?
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Droplets = 1 meter
Aerosol = floats in air |
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Describe different routes of infection + & - s.
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Vector-borne, blood-bone, congenital = virus usually unstable outside of body. Often result in hi viremia and severe ds.
Fecal-oral: virus us stable outside body(must pass pH~2 in stomach and survive stool) Airborne - usually unstable outside body Sexual - us persistent infections (latent enough so no sick much) |
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Describe hosts and definitions
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Arthropods - invertebrate with jointed appendages and chitinous exoskel
Arthropod-Borne Virus = Arbovirus Vector: agent that transmits organism from one host to another Zoonosis: Inf transmitted betw humans and animals Nat Host: Provides reservoir for inf agen in environment (usually not affected) Amplifier host: Augments transmission by Inc #s virus needed to transmit. Dead-end host: no further transmission - Ebola |
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What is stage one in Transmission
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I - Replication and transmission
1. virus transmitted to human in mosq saliva 2. virus replicates in target organ 3. virus infects WBCs & lymphatics 4. Virus released and circulates in blood. |
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What is stage two in Transmission
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Stage II
5. 2nd mosq ingests virus w/blood 6. virus replicates in mosq midgut, infects saliva 7. virus replicates in sal glans |
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Talk about horizontal transmission and incubation period
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Viremia(0-5 day) - mosq feeds (day 5 or so, gets virus) - Extrinsic inculation period (to day 12) - Mosq refeeds, transmits virus - intrinsic incubation period(day 12-20) - new viremia in human #2(day 20-28)
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What is vertical transmission
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infected arthropod feeds on vertebrate(may or may not infect)~Arthropod Ovposts - Egg contains viral RNA ~ Egg hatches: larval, pupal and adult stages ~ Adult emerges, already infected and capable of transmission
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What does FLAVIVIRIDAE family mean in latin?
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"yellow" - yellow fever
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What 3 Genera included in Flaviviridae?
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Flavivirus
Hepacivirus Pestivirus |
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What is included in Flavivirus Genera?
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yellow fever, dengue, JE, STLE, Murray Valley enceph, Tick borne Enceph
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What is vector for Flaviviridae
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All mosquitos-borne except TBEV
(all arthropod borne) |
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Hepacivirus includes what?
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Hepatitis C
which is a blood-borne (parenteral) transmission |
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Characteristics of Flavivirus
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POSITIVE STRANDED, NON-SEGMENTED, RNA ~ 9-13 kc, ~ 50 nm diameter
Icosahedral nucleocapsid Enveloped thru maturaton at intracytoplasmic membranes GlycoP - lie flat along envelope surface Single ORF translated into long pprotein cleaved to make numerous ppeptides |
