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25 Cards in this Set
- Front
- Back
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What are arboviruses
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Arthropod borne viruses
Have obligatory intermediate step in infections where they must go through arthropod vector |
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Differentiate between enzootic and epizootic cycles
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See presentation/syllabus
Enzootic is normal between insect and maintenance host Epizootic, transfer to dead-end host |
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What are two examples of Urban epidemic cycles
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Transmission chain between vector and humans
Dengue and Yellow fever viruses |
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Define zoonosis
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Infection of a human with an animal pathogen
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What are three dominant arbovirus groups (that we discussed)
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Togaviridae, Flaviviridae, Bunyaviridae
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What are the common features of all dominant arboviruses (that we discussed)
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All are single stranded RNA viruses with envelopes
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Describe the genome, biosynthesis, and name examples of togaviridae
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Genome - + ssRNA
Has a polyprotein and subgenomic RNA Arbovirus eg. - Eastern equine encephalitis virus Non-arbovirus eg. - Rubella |
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Describe the genome, biosynthesis, and name examples of flaviviridae
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Genome - + ssRNA
Polyprotein Arbovirus eg. - Yellow fever virus Non-arbovirus eg. - Hep. C virus |
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Describe the genome, biosynthesis, and name examples of bunyaviridae
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Genome - segmented - ssRNA
Polyprotein on one segment Subgenomic RNA from one segment Arbovirus eg. - La Crosse encephalitis Non-arbovirus eg - hantavirus |
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Describe yellow fever virus (YFV)
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Flavivirus
Mosquito-borne Causes jaundice & hemorrhagiv fever High mortality rate |
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Describe the two transmission cycles of yellow fever virus
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Jungle cycle- enzootic = mosquitoes and monkeys; epizootic = human infection, humans infected by jungle mosquito
Urban cycle - High viremia in humans, mosquitoes transmit between humans |
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What are the clinical features of a yellow fever virus infection
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Biphasic illness
Initial phase - headache/fever/chills, muscle pain, nausea, head/neck flushing, strawberry tongue, faget's sign Second phase - brief remission, fever, vomiting, protration, hematemesis (black vomit), deepening jaundice, renal failure, stupor, shock |
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What is the treatment for a yellow fever virus infection
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Treat symptoms, fluid replacement, etc.
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Is there a vaccine for YFV?
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Yes, live attenuated
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Describe the transmission of Dengue Virus (DEN)
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Predominant mode of transmission is by mosquitoes with humans as reservoir
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What are the two diseases caused by the dengue virus
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Classic Dengue Fever ("Bone break fever"
Dengue Hemorrhagic Fever/Dengue Schock Syndrome |
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Describe classic Dengue fever
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Sudden onset of: flu-like symptoms, macular rash, nausea/vomiting, severe muscle/bone pain, arthralgia
Recovery after ~6-7 days |
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Describe Dengue Hemorrhagic Fever
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Two phases
1 - Classic dengue fever with brief remission 2 - Profound prostration, circulatory collapse, dermal & mucous membrane bleeding, hemorrhagic pneumonia, thrombocytopenia ?Immune mediated? |
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What is the treatment for a dengue fever virus infection
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Supportive
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Describe Saint Louis Encephalitis
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Viral encephalitis
Mosquito vector, bird host Febrile headache to encephalitis No antivirals and no vaccine |
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Describe Eastern Equine Encephalitis
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Mosquito vector
Most severe arboviral encephalitides, permanent brain damage common |
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What are the clinical features of Eastern Equine Encephalitis
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Fever, headache, myalgia, photophobia & numbness leading to neurological symptoms
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What is the treatment for Eastern Equine Encephalitis
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Supportive
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Is Western Equine Encephalitis similar to Eastern Equine Encephalitis
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Yes
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Describe La Crosse Encephalitis Virus
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A Bunyavirus
Mosquito vector, squirrel reservoir Most infections subclinical, can cause encephalitis No antivrals, no vaccine |
