RNA viruses - arboviruses Flashcards
What are the types of arboviruses?
Toga, Flavi, Bunya.
What are the subtypes of togavirus?
Alpha viruses (cause encephalitis in horses, birds and humans) Rubivirus (rubella)
What are the three alpha togaviruses that cause encephalitis? What is the vector.
WEE: western equine encephalitis (west US and CAN)
EEE: eastern equine encephalitis (eastern US)
VEE: Venezuelan equine encephalitis
Vector = mosquito.
What the heck is Chikungunya?
Mosquito-borne alpha toga virus that does NOT typically cause encephalitis. Aedes mosquito. Tropical Asia/Africa.
What are the sx of Chikungunya?
Fever, rash (resolves after a few days), joint/pain swelling.
What is the classic clinical presentation of rubivirus?
Rubella
What else is rubella called?
German measles/3-day measles.
What is the presentation of rubella?
Similar to measles but not as bad. Prodrome of fever/flu-like sx, followed by head to toe rash. Resolves in 3 days.
How can rubella present in young women?
self-limiting arthritis.
What happens when rubella is transmitted to a fetus?
Congenital rubella = very bad. Chromosomal breakage and inhibition of mitosis if occurs in first trimester. Presents with heart, eye, and CNS abnormalities.
What does the blueberry muffin appearance of congenital rubella represent?
Extramedullary hematopoesis.
What are the major viruses in the flavivirus family?
HCV, Yellow Fever, Dengue fever, West Nile, and St. Louis encephalitis
Which of the flaviviruses is NOT arthropod borne?
HCV
What is the vector for flaviviruses other than HCV?
mosquito
What is the clinical presentation of yellow fever?
Febrile illness, JAUNDICE, n/v, *black vomit, backache.
Where is yellow fever prevalent?
Africa (90% of cases). Vaccination required for travelers going.
What is the vector for yellow fever?
Aedes mosquito transmitting flavivirus.
What is a liver biopsy finding for yellow fever?
Councilman bodies - eosinophilic apoptotic globules
What kind of virus causes dengue fever? what is the vector?
Flavivirus, mosquite-borne.
Where is the distribution of dengue fever?
Primarily in the tropics, but can occur warm enough - even has occur in US along mexico border.
What is the clinical presentation of Dengue fever?
Initial presentation: backacke, muscle, joint pain, fever.
What is the worst thing to happen re: Dengue?
Repeat infection with a second serotype, especially serotype 2. Causes Dengue hemorrhagic fever - mortality 10%.
What is west nile virus?
A member of a group of closely related flaviviruses that likely spread to the US by bird/mosquitos.
What is the clinical presentation of west nile virus?
Ranges from asymptomatic (most patients) to mild fever & rash, +/- confusion, to frank encephalitis, aseptic meningitis, or paralysis/paresis, with high mortality in the latter group. Immunosuppressed more vulnerable, children fare the best.
What is the second leading cause of viral encephalitis in the US?
St. Louis encephalitis, a flavivirus.
What are the clinical presentations associated with bunyaviridae?
California encephalitis, Sandy/Rift Valley Fever, Crimean-congo hemorrhagic fever, and hantavirus
Where have outbreaks of hantavirus in the US been centered?
Southwestern US: New Mexico, Arizona, Colorado, and Utah
What has been the presentation of hantavirus in the US?
Flu-like symptoms followed by pnuemonia and sudden respiratory failure, often fatal.
What is the vector and reservoir for hanta virus?
Rodents
What clinical presentation is hantavirus associated with in Asia and Europe?
Hemorrhagic fever with renal failure
