Other scary RNA viruses that cause badness Flashcards
What kind of virus causes rabies?
Rhabdoviruses.
What is distinctive about the rhabdo capsid?
Bullet shaped.
What happens when a human is bitten by a rabies infested animal?
Virus replicates locally at the wound site for a few days, then migrates (slowly, weeks to a year) up nerve axons to CNS (binds to Ach receptors), causing fatal encephalitis.
What histologic findings are associated with rabies?
Negri bodies - collections of virions in the cytoplasm of purkinje cells of the cerebellum and in hippocampal neurons.
Progression of rabies disease?
1) prodrome w/ non-specific sx, + sensitive nerves around healed wound site
2) acute encephalitis: hyperactivity and agitation/seizures - madness!
3) Brainstem encephalitis: cranial nerve dysfunction leads to pain with swallowing - hydrophobia, hypersalivation.
4) Paralysis, coma, death due to respiratory center dysfunction.
What is the post-exposure prophylaxis for rabies exposure?
Wound cleaning + immunization with killed vaccine and rabies immunoglobulin.
What happens to the animal who bit?
Captured and confined/destroyed.
If confined, observe for 10 days, if no sx, no rabies.
If killed, dead animals brain can be examined for negri bodies.
What are two famous filoviruses?
Ebola and marburg
How does ebola virus works?
Targets endothelial cells, phagocytes and hepatocytes.
What is the clinical presentation of ebola?
Flu-like symptoms, followed by diarrhea/vomiting, high fever, myalgia. Can progress to DIC/diffuse hemorrhage, shock.
How is ebola transmitted?
direct contact with bodily fluids or fomites. High incidence of nosocomial infection.
What are the arenaviruses?
Lassa Fever virus, and 4 south american hemorrhagic fever viruses: Junin, Machupo, Guanarito, and Sabia virus. Similar to ebola but treatable with ribavirin.
