MICR 483 Module 6 Study Guide
Arbovirus - Answer arthropod borne virus
→ mosquitoes, sand flies, lice, fleas, ticks, mites
80 different diseases, 500 different viruses
can be +ssRNA, -ssRNA, dsRNA
Flaviviridae viruses - Answer +ssRNA: divided into 4 genera
Genus Flavivirus
→ Zika, West Nile, Dengue. also Yellow Fever, Chikungunya, Japanese encephalitis.
Genus Hepacivirus
→ Hepatitis C virus
Genus Pegivirus
→ Pegivirus A; infects humans but doesn't cause disease
Genus Pestivirus
→ Bovine viral diarrhea virus (BVDV)
Arthropod Vectors - Answer most common vector for emerging arboviruses
illnesses from arthropods have tripled from 2004 to 2016.
→ 9 new species found.
epidemiology: infections occur when vector is present
→ temperate climates: seasonal—when mosquitoes are out.
→ less annual in tropical climates.
Animal Reservoirs - Answer zoonoses; about 58% of human pathogens are zoonotic
among "emerging" viruses, proportion is even higher
,→ 13% of all human pathogens are emerging; 73% of those are zoonotic
Infectious Disease cycles - Answer sylvatic life cycle
→ most viruses follow this, but it spills over in both domestic animals & humans, initiating the
next two.
Rural life cycle
urban life cycle
Sylvatic Life Cycle - Answer a life cycle that occurs in wild animals—aka *enzootic* cycle
animal infected by insect vector, that infects other insect vectors. cycle leads to viral
amplification
animal = reservoir host.
Rural cycle - Answer sylvatic leads to here.
aka *epizootic* cycle
virus cycled between non-wild/domestic animals & insect vector
leads to outbreak of viral disease in domestic animal population; amplified virus in host
→ *amplifying host*
implication it can spill over to human hosts
Urban Life cycle - Answer *epidemic* cycle
pathogen cycles between insect vector and humans
homans are source of infection due to high viremia
mosquito bites human and moves on to infect other humans
, humans can also be infected via *bridge vector*, becoming *incidental host*
Bridge vector - Answer arthropod that acquires virus from an infected wild animal and
subsequently transmits the agent to human or secondary host
human infected from sylvatic cycle
Incidental host - Answer intermediate host that does not allow transmission of virus to
definitive host
insufficient viremia to be picked up by insect vectors
Mosquito species - Answer Anopheles
→ plasmodium
Aedes
→ Zika
→ Dengue
→ Chikungunya
Culex
→ West Nile
→ Japanese Encephalitis
Aedes mosquito - Answer Feeding
→ bite during daytime unlike normal
→ so, medicated bed-nets aren't effective
→ gentler landing & softer btie that you can't feel due to anesthetic evolution
→ no buzzing noise
Reproduction
→ lay gs just above water line, use natural pools
→ mosquito eggs remain dormant if pool dries up; but rain water will flood eggs, causing
hatching
Arbovirus - Answer arthropod borne virus
→ mosquitoes, sand flies, lice, fleas, ticks, mites
80 different diseases, 500 different viruses
can be +ssRNA, -ssRNA, dsRNA
Flaviviridae viruses - Answer +ssRNA: divided into 4 genera
Genus Flavivirus
→ Zika, West Nile, Dengue. also Yellow Fever, Chikungunya, Japanese encephalitis.
Genus Hepacivirus
→ Hepatitis C virus
Genus Pegivirus
→ Pegivirus A; infects humans but doesn't cause disease
Genus Pestivirus
→ Bovine viral diarrhea virus (BVDV)
Arthropod Vectors - Answer most common vector for emerging arboviruses
illnesses from arthropods have tripled from 2004 to 2016.
→ 9 new species found.
epidemiology: infections occur when vector is present
→ temperate climates: seasonal—when mosquitoes are out.
→ less annual in tropical climates.
Animal Reservoirs - Answer zoonoses; about 58% of human pathogens are zoonotic
among "emerging" viruses, proportion is even higher
,→ 13% of all human pathogens are emerging; 73% of those are zoonotic
Infectious Disease cycles - Answer sylvatic life cycle
→ most viruses follow this, but it spills over in both domestic animals & humans, initiating the
next two.
Rural life cycle
urban life cycle
Sylvatic Life Cycle - Answer a life cycle that occurs in wild animals—aka *enzootic* cycle
animal infected by insect vector, that infects other insect vectors. cycle leads to viral
amplification
animal = reservoir host.
Rural cycle - Answer sylvatic leads to here.
aka *epizootic* cycle
virus cycled between non-wild/domestic animals & insect vector
leads to outbreak of viral disease in domestic animal population; amplified virus in host
→ *amplifying host*
implication it can spill over to human hosts
Urban Life cycle - Answer *epidemic* cycle
pathogen cycles between insect vector and humans
homans are source of infection due to high viremia
mosquito bites human and moves on to infect other humans
, humans can also be infected via *bridge vector*, becoming *incidental host*
Bridge vector - Answer arthropod that acquires virus from an infected wild animal and
subsequently transmits the agent to human or secondary host
human infected from sylvatic cycle
Incidental host - Answer intermediate host that does not allow transmission of virus to
definitive host
insufficient viremia to be picked up by insect vectors
Mosquito species - Answer Anopheles
→ plasmodium
Aedes
→ Zika
→ Dengue
→ Chikungunya
Culex
→ West Nile
→ Japanese Encephalitis
Aedes mosquito - Answer Feeding
→ bite during daytime unlike normal
→ so, medicated bed-nets aren't effective
→ gentler landing & softer btie that you can't feel due to anesthetic evolution
→ no buzzing noise
Reproduction
→ lay gs just above water line, use natural pools
→ mosquito eggs remain dormant if pool dries up; but rain water will flood eggs, causing
hatching
