Clinical virology Flashcards

Question

Coronaviruses

Answer 1

ssRNA, helical, enveloped | - "common cold" and SARS

Answer 2

ssRNA, helical, enveloped | - Influneza virus

Answer 3

ssDNA, helical, enveloped *Have surface F (fusion) protein --> resp endothelial cells fuse/multinucleate * PaRaMyxovirus* - Parainfluenza (Croup = seal-like bark cough) - RSV - bronchiolitis in infants, Rx = ribavarin - Measles, Mumps * Palivizumab = monoclonal Ab against F protein, prevent pneumonia from RSV in premies * MMR = live attenuated vaccine

Answer 4

ssRNA, helical, enveloped | - Ebola/Marburg hemorrhagic fever --> often fatal

Answer 5

ssRNA, helical, enveloped - LCMV = lymphocytic choriomeningitis virus - Lassa fever encephalitis - spread by mice

Answer 6

ssRNA, uncertain capsid, enveloped | - HDV = "defective" virus that requires HBV co-infection

Answer 7

ssRNA, helical, enveloped - California encephalitis - Sandfly/Rift Valley fevers - Crimean-Congo hemorrhagic fever - Hantavirus - hemorrhagic fever, pneumonia

Answer 8

Must transcribe neg strande to positive - Virion brings own RNA-dependent RNA polymerase - Arenavirus, Bunyaviruses, Paramyxoviruses, Orthomyxoviruses, Filoviruses, Rhabdoviruses "Always Bring Polymerase Or Fail Replication"

Answer 9

All are RNA viruses BOAR: - Bunyaviruses - Orthomyxoviruses (influenza) - Arenaviruses - Reoviruses

Answer 10

Flavivirus - Transmit: Aedes mosquito (monkey/human reservoir) - Sxs: high fever, black vomitus, jaundice *Flavi = yellow, jaundice*

Answer 11

Reovirus, dsDNA, segmented - Major caused of diarrhea in kids --> infantile gastroenteritis! - Villous destruction w/ atrophy = decr Na+ absorption, loss of K+ * ROTAvirus = Right Out The Anus* - Vaccination (live attenuated)

Answer 12

Orthomyxoviruses - ssRNA, enveloped, 8-seg genome - Hemagglutinin (vira entry) and neuraminidase (progeny virion release) - Rapid genetic changes - At risk for fatal bacterial superinfection * Vaccines: contain few strains - Killed - injected, most common - Live attenuated - intranasal (replicates in nose, not lung)

Answer 13

Togavirus --> Rubella = German measles - Fever, postauricular and other LAD, arthralgia, fine rash (start face, move centrally + extrem) - Mild disease in children - Serious congenital (ToRCHeS infection!) --> cataracts, deafness, blueberry muffin appearance (extramedullary hematopoeisis)

Answer 14

Paramyxovirus, causes measles (rubeola) - CCC: coryza, cough, conjunctivitis - Koplik spots + descending maculopapular rash - SSPE - subacute sclerosing panencephalitis --> yrs later * Mutated/absent matrix protein, evades immune system + replicates in neurons * MMR vaccines - live attenuated * VitA to prevent exfoliative dermatitis in malnourished

Answer 15

Paramyxovirus Mumps makes parotid/testes as big as POM-poms: - Parotitis, Orchitis (inflamm testes), aseptic (viral) Meningitis *Can cause sterility after puberty

Answer 16

Bullet-shaped, Negri bodies in Purkinje cells of cerebellum/hippocampus - Incubation = wks-months before sx - Travels to CNS retrograde (up axon cells) - Sx: fever, malaise --> agitation, photophobia, hydrophobia --> paralysis, coma --> death * More from bat, raccoon, skunk bites than dogs in US - PEP = wound wash, vaccine +/- rabies Ig

Answer 17

Sx - fever, jaundice, high ALT/AST "Picked Hell - Fibrosis Death Hepatomegaly" - HAV - RNA picornavirus - HBV - DNA hepadnavirus - HCV - RNA flavivirus - HDV - DNA delta virus - HEV - RNA hepevirus *A and E = fecal-oral (vowels hit your bowels) --> naked viruses, dont rely on envelope, so not destroyed by gut

Answer 18

RNA picornavirus - Fecal-oral transmission - No carries - Short incubation = weeks - No risk HCC *HAV = Asymptomatic, Acute, Alone (no carrier)*

Answer 19

DNA Hepadnavirus - Parenteral, sexual, maternal-fetal - Carriers - Long incubation = months - HCC risk - integrates into host genome (acts as oncogene)

Answer 20

RNA Flavivirus - Blood transmission (IVDU, tattoos) - Carriers - Long incubation - HCC risk - chronic inflammation *HCV = Chronic, Cirrhosis, Carcinoma, Carrier*

Answer 21

RNA Deltavirus - Parental, sexual, maternal-fetal - Carriers - Superinfection (HDV after HBV) = short incubation - Co-infection (HDV with HBV) = long (like HBV) - HCC risk *HDV = Defective virus Dependent on HBV; superinfection is worse prognosis*

Answer 22

- Anti-HAV (IgM) - IgM ab to HAV (detects active HAV) - Anti-HAV (IgG) - IgG ab to HAV (detects prior infec/immuniz) - HBsAg - antigen on surface of HBV = HBV infection - Anti-HBs - Ab to HBsAg --> HBV immunity - HBcAg - antigen assoc w/ HBV core - Anti-HBc - Ab to HBcAg; IgM = acute/recent infection, IgG = prior exposure/chronic infection * + during window period* - HBeAg - active viral replication = high transmissibility - Anti-HBe - ab to HBeAg = low transmissibility *SECES: SE = antigens, CES = abs

Answer 23

RNA Hepevirus - Fecal-oral (esp waterborne epidemic) - No carriers - Short incubation - No HCC risk - High mortality in pregnant women! * Biphasic: 1 = self-limited, 2 = high serum transaminases, rise in IgM anti-HEV (correlates w/ disease) *HEV - Enteric, Expectant mothers, Epidemic*

Answer 24

- Anti-HBs appear late (after HBsAg disappear = window period) - Anti-HBc appear early, continue (IgM vs. IgG)

Answer 25

Viral: ALT>AST Alcoholic: AST>ALT

Answer 26

- Binds CCR5 (early) or CXCR4 (late) co-receptor + CD4 on Tcells - Binds CCR5 and CDR on macrophages * Homo CCR5 mutation = immunity * Hetero CCR5 mutation = slower disease progression

Answer 27

Retrovirus, carries own reverse transcriptase 3 structural genes: 1) env (gp120, gp41 --> cleavage of gp160) - gp120 = docking protein (attach to CD4Tcell) - gp41 = fusion/entry 2) gag (p24) = capsid protein (conical) 3) pol - reverse transcriptase, aspartate protease, integrase * Reverse transcriptase synthesizes dsDNA from RNA --> incorporates into host genome 2 regulatory genes: - tat + rev (for viral replication)

Answer 28

1) ELISA - high false positive (rules-out) 2) If +, do Western blot - high false negative (rules-in) 3) PCR/viral load - higher viral load = worse prognosis; can monitor drug response this way * ELISA/western blot test antibody to viral proteins - False neg in mo 1-2 - Babies born to infected mom (anti-gpl120 crosses placenta)*

Answer 29

4 stages: - Flu-like feeling (acute) - dissemination of virus, seed lymphoid organs - Feeling fine (latent) - viral replic in LNs - Falling CD4 count - Final crises - constitutional sx/opportunistic disease

Answer 30

- CD4 count < 200 - HIV + AIDS defining illness (OIs) - CD4 count <14%

Answer 31

As CD4+ drops, risk of reactivation of past infections (TB/HSV/shingles), dissemination of bacterial/fungal infections (coccidioidomycosis), non-Hodgkin lymphoma

Answer 32

Convert normal a-helical protein termed prion protein (PrPc) to B-pleated form (PrPsc) = more transmissible - PrPsc resists protease degradation, converts more PrPc to PrPsc - Get spongiform encephalopathy - from accumulation of PrPsc - Sx - encephalopathy, dementia, ataxia, death - Cruetzfeldt-Jakob disease - rapidly progressive dementia, sporadic - Also acquired (GSS syndrome) or acquired (kuru)