RNA viruses + mixed! - Sheet1 Flashcards
Reoviruses
“REO: Rapid Enteric Orphan” = children get diarrhea!
dsRNA**, linear (10-12 semgents), naked -ICOSAHEDRAL (double) =Coltivirus: Colorado tick fever =ROTAVIRUS: #1 cause of fatal diarrhea in children --> villous destruction.atrophy (decr absorption of Na+ and loss of K+) **ROTA vaccine! ROTA: Right Out The Anus
Picornavirus
“Enterovirus”
ssRNA +, naked (–> 1 large polypeptide that is cleaved by proteases–>fxnl)
-ICOSAHEDRAL
=Poliovirus: Salk IPV / Sabin OPV: aseptic meningitis, assymmetric paralysis, hyporeflexic.
=Echovirus: aseptic meningitis
=Rhinovirus: “common cold” (acid-labile=destroyed in GI, binds to ICAM-1/CD54)
=Coxsackievirus: aseptic meningitis, herpangina (mouth blisters,fever): HAND FOOT MOUTH ds, Myocarditis
=HAV: acute Hepatitis A
-all are fecal-oral except rhino(acid-labile)
PERCH your NAKED self on this Railing for the PICture, you look POSitively goregous!!
**most common cause of aseptic meningitis (Polio, Echo, Coxsackie)
Hepevirus
ssRNA+, naked, icosahedral
=Hepatitis E
Calcivirus
ssRNA+, naked, icosahedral
=Norovirus –> viral gastroenteritis (cruise ships!)
-NORa wanted to drink enough CALCIum crystal/icosahedral before her SINGLE Ride on the beach/naked cruise ship
Flavivirus
ssRNA+, evenloped, Icosahedral =Hepatitis C =Yellow Fever (Aedes mosquito) =Dengue (m) "Breakbone fever" =St. Louis encephalitis (m) =West Nile Virus (m)
Wear a rain jacket/envelope in Africa down the West Nile (river = single stranded, raft: icosahedral shaped)!
Togaviruses
ssRNA+, envelope, icosahedral
=Rubella (“german measles”)
=Eastern equine encephalitis (mt)
=Western equine encephalitis (mt)
Toga party at the German Equine center! sounds Positively fun!
Retrovirus
ssRNA+, envelope (reverse transcriptase activity)
=HTLV-1: icosahedral, T-cell leukemia
=HIV: complex/conical
-do not replicate in the cytoplasm like the other RNA viruses
Wear a condom/Envelope so you don’t get HIV and HTLV-1!
Coronavirus
ssRNA+, envelope, helical*
=Coronoavirus: common cold and SARS
Orthyomyxovirus
ssRNA-, evenlope, helical, (8 segments)
=INFLUENZA! contains hemagluttinin (promotes viral entry) and Neuraminidase (promotes progeny virion release)
-does not replicate in the cytoplasm like the other RNA viruses
-pts at risk for bacterial superinfection
-Rapid genetic changes
Those ORTHO guys think they are awesome (do 8 sets at the gym, helical bench-press bar) but they didn’t get the flu shot this year: INFLUENZA shot (NEGative)
-also they have sex a lot probably so they need alot of envelopes, but they make your head spin/HELICAL bc they have no emotional maturity - hence they are SINGLE
Paramyxoviruses
ssRNA-, envelope, helical
=Parainfluenza: croup (upper resp sxs –> hoarseness, barking/brassy cough, strider)
=RSV: bronchiolitis in babies, Rx: Palivizumab/Ribavirin (anti-F) upper resp sxs –> wheezing, cough, resp distress
=Measles
=Mumps
-all contain surface F/FUSION protein: causes respiratory epithelial cells to fuse –> MULTINUCLEATED cells
PaRaMyxo (Parainfluenza, RSV, Mumps/Measles)
“Myxo” mix it all up, created fused cells! multinucleate!
Rhabdovirus
ssRNA-, envelope (BULLET-SHAPED), helical
-glycoprotein spikes that bind to nicotinic Ach receptors
=RABIES
dogs like helical chew toys bc they look like bones. wrap it up in an envelope so you don’t have to touch their gross saliva!
Filoviruses
ssRNA-, envelope, helical
=Ebola/Marburg hemorrhagic fever
Filo dough that E-BOWL-right-UP!
(filo dough = ENVELOPE, rolled tight like a HELIX
Arenavirus
ssRNA-, CIRCULAR 2 segments, envelope, helical
=LCMV: Lymphocytic choriomeningitis virus (mice!); febrile aseptic meningoecephalitis
=Lassa fever encephalitis: spread by mice (mice!)
Arenas are CIRCULAR. Tibetan mice on the race track (Lassa Fever), Let’s Cee them MoVe! 2 segments = the Tibetan Mice vs the others (2 teams)
Bunyaviruses
ssRNA-, CIRCULAR 3 segments, envelope, helical
=California encephalitis (mt)
=Sandfly/Rift valley fevers (mt)
=Crimean-Congo hemorrhagic fever (mt)
=Hantavirus- hemorrhagic fever, pneumonia (rats)
Bunyans are on the big toe and are tumors that are CIRCULAR
Delta virus
ssRNA-, CIRCULAR, envelope, shape?
=Hepatitis D (D for delta) - is “Defective” and requires HBV co-infection
The Delta virus has CIRCULAR RNA bc it looks the most like HBV then - whoes coating it neds
Negative stranded RNA viruses (-ssRNA)
Always Bring Polymerase Or Fail to Replicate (transcribe neg to positive) Arenavirus Bunyavirus Paramyxovirus Orthomyxovirus Filovirus Rhabdovirus
Segmented viruses
All are RNA viruses: BOAR (you cut up to serve!) Bunyavirus Orthomyxovirus (influenza) Arenaviruses Reoviruses
Yellow Fever
- a Flavivirus
- transmitted by Aedes mosquito, Human or Monkey reservoir
- sxs: High fever, BLACK vomit, JAUNDICE (“yellow” fever bc you turn yellow)
Influenza: Shift and Drift
- Shift: pandemics. Reassortment of virla genome, segments undergo high-frequency recombination
- Drift: epidemics. Minor (antigenic drift) from random mutations
Sudden Shift is more deadly than graDual Drift
Rubella
“German measles!”
- Togovirus
- sxs: Fever, post-Auricular** lymphadenopathy, arthlragias*, fine truncal rash (head –> moves down = truncal rash (no hands and feet vs measles))
- Congenital in children: deafness, cataracts, cardiac malformation (PDA)
Measles
- Paramyxovirus
- 3 C’s: Cough, Coryza (nasal mucosal inflammation), Conjunctivitis
- sxs: KOPLIK spots (cheek mucosa: red spots w blue-white center), Descending rash (head –> down) that can darken/coalesce (presents last, includes hands and feet vs rubella).
- -> possible sequale: SSPE Subacute Sclerosing Panencephalitis (yrs later), Encephalitis, Giant Cell Pneumonia
Mumps
- Paramyxovirus
- sxs: Parotitis, Orchitis (inflammation of testes), aseptic Meningitis –> sterility in puberty
mumps make your parotid glands and testes as big as POM-poms
Rabies
Rhabdovirus
- NEGRI body inclusions (Purkinje cells in cerebellum)
- Long incubation period
- Postexposure rx: wound cleanign, vaccination + rabies IgG
- virus goes to CNS by retrograde travel on nerve axons (attachs to nicotinic Ach receptors)
- sxs: Fever malaise –> dysphagia/pharyngospasm, AGITATION, PHOTOPHOBIA, HYDROPHOBIA, excess saliva –> Paralysis, coma, death
- Bats (caves), raccoons, skunk bites, dogs
Hepatitis: short incubation periods
Hep A, E, and D when it’s super-infecting
Hepatitis A
- RNA Picornavirus
- Fecal-oral, shellfish/oysters
- short incubation period, no HCC risk
- Asxs (usually), Acute, Alone (no carriers)
- sxs: AVERSION to SMOKING. anorexia, abdml pain, fever, etc.
Hepatitis B
- DNA Hepadnavirus
- Blood, semen, saliva, sweat, tears, breast milk*
- Long incubation
- carries its own RNA-dependent DNA polymerase
- -> HCC bc integrates itself into host virus (acts as oncogene)
Hepatitis C
- RNA Flavivirus
- primary blood transmission (IVDU, post-transfusion)
- long incubation
- -> HCC from chronic inflammation
- Enevelope has high mutation rate - ab’s lab behind
- Chronic, Cirrhosis, Carcinoma, Carrier, CURE
Hepatits D
RNA Delta virus
- Blood, semen, saliva, sweat , maternal-fetal*
- superinfxn: short incubation. co-infection: long incubation
- Defective virus, Dependent on HBV
- superinxn? poor prognosis
Hepatitis E
RNA, hepevirus
- fecal oral, esp w waterborne epidemics
- no envelope
- short incubation period, High mortality in pregnant women**
- Enteric, Expecting mothers, Epidemic
Path: acute hepatitis
Ballooning degeneration, mononuclear cell infiltrates, Councilman bodies/eosinophilic apoptotic hepatocytes
-fever, jaundice, elevated ALT/AST
HIV proteins
- gp120: enveleop, attachment to CD4+ (anti gp-120 can cross placenta, see false positve in babies born to infected mothers)
- gp41:fusion and entry
- gp120 and gp41 made from cleavage of gp160
- gag(p24): capsid protein
- pol: reverse transcriptase, aspartate protease, integrase
HIV replication
- T cells: Binds to CD4+ and CCR5 (early) or CXCR4 (late)
- macrophages: CD14 and CCR5
HIV dx
- 1) ELISA: sensitive (rule it out)
- 2) Western blot: specific (rule it in)
- HIV PCR/viral load test: monitoring
Time course of HIV
- 1) Flu-like sxs (acute - drop in CD4, dissemination of virus, seeding of Lymphoid organs)
- 2) Feeling fine (latent: HIV replicate in LNs)
- 3) Falling count
- 4) Final crisis
As CD4 count drops…
- risk of reactivation of past infxns (TB, HSV, shingles)
- dissemination of bacterial and fungal infxns (e.g. coccidiomycosis)
- NHL (latent EBV reactivation): DLBCL
Prions
- nl protein: Prion PrPc –> Prpsc
- -> Spongiform encephalopathy, dementia, ataxia, death
- Creutzfeldt-Jacob ds: sporadic
- Gerstmann-Straussler-Scheinker syndrome: inherited
- Kuru: acquired