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25 Cards in this Set
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croup
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parainfluenza virus
occurs in children, you get airway narrowing and stridor (blockage) and barking cough Has Fusion protein (causes multinucleated giant cells - syncytia) and HA and NA |
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#1 cause of pneumonia and bronchiolotis in infants (esp <6 mo)
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RSV
also causes otitis media in children, pneumonia in elderly and pts with chronic cardio-pulmonary disease Has Fusion protein (causes multinucleated giant cells - syncytia) but no HA or NA |
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Measles - its prodrome?
its 4 "c's" why does the rash form? how does the rash spread? what is a complication? |
Rubeola virus
Prodrome - high fever, eyelid swelling/conjunctivitis, photophobia, rhinitis, hacking cough, malaise Cough, Coryza (runny nose), conjunctivitis, Koplick's spots & high fever & rash (due to cell mediated immunity after virus infects vascular endothelium) rash spreads: forehead --> face --> neck --> torso + upper extremities --> lower extremities. It begins disappearing on head as it reaches legs. (like pouring paint) complication: SSPE (subacute sclerosing pan-encephalitis - slow encephalitis w/ mental deterioration) Has Fusion protein (causes multinucleated giant cells - syncytia) and HA and NA |
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Mumps
what are two main sites involved and also some complications? |
Mumps virus (a paramyxovirus)
parotitis, orchitis (possible sterility), Comp: meningitis, encephalitis, deafness, pancreatitis Has Fusion protein (causes multinucleated giant cells - syncytia) and HA and NA |
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Hepatitis A
What family of viruses? Mode of transmission? What liver enzymes are elevated? How do you tell if person has immunity |
Picornaviridae, fecal-oral transmission (as with most picornaviridae)
Elevation of AST/ALT (more so than GGT/alkphos/bilirubin) Anti-HAV IgG confers protection, indicates an old infection |
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Hepatitis B
What family? Whats a intact particle called? What does it have in it? What does the vaccine consist of? What antigens? What antibodies are protective? What do the antibodies against the 3 different antigens mean? |
Hepadnaviridae
Intact virus: Dane particle DNA polymerase, icosahedral capsid, envelope, proteins, dsDNA HBcAg (-->HBeAg), HBsAg antiHBsAg antibodies are protective (patient is immune to HBV) antiHBcAg antibodies are not protective but can be used for timeline (IgM = new infection, IgG = old infection) HBeAg antigen indicates active disease/infectious state bc its only released when virus is growing anti-HBeAg means not infectious Vaccine consists of HBsAg ONLY (so they wont have anti-HBeAg or anti-HBcAg) |
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What antibody profile would a chronic HBV carrier show?
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failure to develop anti-HBsAg antibodies, has HBsAg antigen
may have anti-HBcAg antibodies (first IgM then IgG theyre not protective) may have anti-HBeAg or not, depending on if theyre non-infectious or are infectious |
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How is one protected against Hep D?
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Antibodies against HBsAg (anti-HBsAg) also protect against HDV because it uses the HBV envelope/proteins
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Rabies
How is it caused? What histologic sign is pathognomonic of Rabies? What symptoms does it cause? |
Rabies is caused by Rhabdovirus, which has bulletshaped, enveloped, helical symmetry nucleocapsids
It is caused by bite of dogs/bats/racoons or any warm-blooded animal Negri bodies - collections of virions in cytoplasm of brain cells (pathognomonic) Bite --> general viral prodrome + painfully sensitive nerves at bite site --> acute encephalitis + mental confusion--> classic brainstem encephalitis (foaming of mouth due to inability to swallow and inc saliva production) --> death due to respiratory center dysfunction |
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Retroviruses:
Whats the difference between acute transforming viruses and non-acute transforming viruses? |
acute transforming viruses carry a oncogene and insert it into our DNA,
whereas non-acute transforming viruses merely integrate viral DNA into a key regulatory area, activating a host proto-oncogene |
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Retroviruses:
What is: LTR |
LTR: long terminal repeats, serve 2 functions:
1) has sticky ends to integrate into host, 2) proteins may bind to it and activate its promoter/enhancer function |
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Retroviruses:
What is: gAg (gag=Group Antigen) |
gAg: codes for virion's major structural proteins that are antigenic (nucleocapsid, capsid-p24, matrix)
Remember: gAg = group Ag, codes for proteins that are Ags |
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Retroviruses:
What is: pol |
pol: codes for protease, integrase + reverse transcriptase. (protease cleaves gag and pol proteins from larger precursor molecules, integrase integrates DNA into hosts DNA)
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Retroviruses:
What is: env |
env: codes for the ENVelope that glycosylates to form gp spikes gp 120 and 41. gp 120 = the head, gp 41 = the stalk, together they are gp 160 and bind CD4 receptors.
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Retroviruses:
What are tat, rev and nef? |
they are regulatory proteins:
tat: encodes viral trans-activator protein (binds to viral genome and activates transcription) rev: promoter that revs up viral production (by binding to env gene to decrease its splicing --> thus increasing reading of gag, pol and env (big genes) to make virions - this works because ENV is a big gene that may be cut up to make tat, rev, nef) nef: unknown mechanism |
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What are the Receptors involved in HIV binding?
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Primary interaction is HIV's gp160 (gp120+gp41) binding to CD4.
Secondary interaction is with CXCR4 (primarily on CD4+ T cells) OR with CCR5 (primarily on macrophages) |
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What are the main opportunistic infections once CD4+ T cell goint goes below 200 in HIV?
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Pneumocystis carinii pneumonia, Cryptococcus neoformans (meningitis), Toxoplasma gondii (brain mass)
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What is a pathogen that infects once CD4 T cell count drops below 50 in HIV+ patients?
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Mycobacterium Avium-intracellulare
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How are multinucleated giant cells formed in HIV?
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when virus infects, it leaves its gp160 in the membrane of the cell.
These gp 160 in the infected cell can bind to CD4 receptors on adjacent CD4 T helper cells, resulting in cell-to-cell fusion. (up to 500 can bind together) |
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How is HIV virus carried to the CNS and result in neurologic disease?
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It is carried to CNS in monocytes and macrophages, which migrate across the blood-brain barrier. It can result in encephalopathy (causing AIDS dementia complex). Meningeal infection can result in aseptic meningitis. Spinal cord can be affected --> myelopathy, and PNS involvement --> peripheral neuropathy
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What malignancies do AIDS patients often suffer from?
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1) B cell lymphomas which often present as brain mass- (due to disturbed B cell regulation by CD4 T cells; there is also polyclonal activation of B cells resulting in hypergammaglobulinemia)
2) Kaposi's sarcoma - which requires HHV-8 |
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What causes Oral Hairy Leukoplakia?
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Epstein Barr Virus in immunocompromised patients (think AIDS)
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Viral cause of pleurodynia?
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Coxsackie B
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What does Coxsackie A cause?
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Herpangina! (only coxsackie A)
Also causes resp infections, rashes, aseptic meningitis (coxsackie B does this all too) |
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What is the most common cause of aseptic meningitis in US?
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enteroviruses (coxsackie a and b, echoviruses and "new" enteroviruses)
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