RNA virus 3.17.14 Flashcards
Double Stranded, Segmented, Non envoloped RNA Viruses (2)
Reoviridae
1) Rotavirus
2) Coltivirus
Picornaviruses: envelope? Structure? Capsid? Viruses? Clinically?
1) No envelope
2) RNA SS+ linear
3) Icosohedral
4) PERCH
Polio; Echo; Rhino; Coxsackie; HAV
5) Asceptic meningitis (except rhino); Fecal-oral route (except rhino)
Polio Virus: Virus family? RNA structure? Clinical
1) Picornavirus
2) RNA SS+ linear
3) flaccid paralysis of lower limbs and trunk; troubled breathing; lymphocytosis on CSF; normal glucose and protein
Coxsackie A,B: Family? Structure? Clinical?
1) Picornavirus
2) RNA SS+linear
3a) Herpangina: sore throat and fever; vesicles in oral cavity (hand foot and mouth disease)
b) Pleurodynia: myocarditis; pericarditis
A/B Asceptic meningitis; paralysis; URT infection
1) Picornavirus
2) RNA SS+ linear
3) flaccid paralysis of lower limbs and trunk; troubled breathing; lymphocytosis on CSF; normal glucose and protein
Polio Virus: Virus family? RNA structure? Clinical
1) Picornavirus
2) RNA SS+linear
3a) Herpangina: sore throat and fever; vesicles in oral cavity (hand foot and mouth disease)
b) Pleurodynia: myocarditis; pericarditis
A/B Asceptic meningitis; paralysis; URT infection
Coxsackie A,B: Family? Structure? Clinical?
Most common causes of asceptic meningitis? 3
Coxsackie (Picorna)
Echo (Picorna)
Mumps
Causes of Palm and sole rash (3)
1) Syph
2) Rocky Mountain Spotted Fever
3) Coxsackie
Hep A: Family? Structure? Capsid? Transmission?Clinical
1) Picorna
2) RNA SS+
3) Icosohedral
4) Fecal oral
5) Jaundice; elevated liver enzymes; (A and E are the less toxic forms of Hep); will see IgM in serum; IgG indicative of past infection
5 out of 10 children in a fourth grade class present with nausea, vomiting, loss of appetite and appear yellow. What is the virus? Family? Structure? Capsid?
1) Hep A
2) Picorna
3) SS+
4) Icosohedral
Rhino: Family? Structure? Capsid? Clinical?
1) Picorna
2) RNA SS+
3) Icosohedral
4) Common cold; replicates in the cooler nose and the warmer lungs
rhino has a runny nose
Norwalk: Family? Structure? Capsid? Clinical?
1) Calici
2) RNA SS+
3) Icosohedral
4) Gastroenteritis; contaminated water/food; major cause of group related diarrhea
Family goes out to dinner and develops bout of diarrhea. Organism? Family? Structure?
1) Norwalk
2) Calici
3) SS+
Hep E: Family? Structure? Capsid? Clinical?
1) Calici
2) RNA SS+
3) Icosahedral
4) Jaundice and hepatomegaly; must rule out HAV; high mortality in pregnant women;
1 cause of fatal diarrhea in children? Family? Structure?
Rotavirus; RNA Double stranded (only double stranded RNA virus)
Colorado Tick Virus: Envelope? Structure? Capsid? Clinical? Transmission?
1) No envelope
2) DS linear RNA 10-12 segments (only double stranded RNA Virus)
3) Icosahedral
4) Fever; myalgias; ocular pain; headache
SHOULD AVOID ASPIRIN FOR FEAR OF HEMORRHAGE
5) Rodents
Rockey Mountain hicker begins to feel fever and muscle aches. Bit by ticks. Diagnosis? Type of bug? What should patient avoid?
1) Colorado Tick Virus
2) Reoviridae Coltivirus (RNA double stranded)
3) Avoid Aspirin and any contact to prevent hemorrhage
Rotavirus: Envelope? Structure? Capsid? Clinical? Transmission? Diagnostic test?
1) No envelope
2) RNA DS linear; segmented
3) Icosahedral
4) Watery diarrhea (Gastroenteritis)– make sure to rehydrate
5) Fecal oral
6) ELISA
3yo presents with severe bouts of vomiting and watery diarrhea for past two days. No blood in diarrhea. Diagnosis? Lab?
1) Rotavirus (RNA DS linear)
2) ELISA
EEE/VEE/WEE: Envelope? Structure? Capsid? Clinical? Transmission?
1) Togaviruses have an envelope (need an invitation to the toga party)
2) RNA SS+
3) Icosahedral
4) Photophobic; head/neck pain; hemiparesis
5) Carried in birds or horses and transferred to humans via mosquitos
8yo girl presents to ED with head and neck pain; photophobia; heiparesis and CN deficits. Bitten by mosquitos recently. Bug? Transmission?
1) EEE/WEE/VEE
2) Carried in birds and horses; transmitted to humans via mosquitos
Rubella: Envelope? Structure? Capsid? Clinical? Transmission?
1) Togavirus has an envelope (need invitation to toga party) (but NOT transmitted by arthropod!)
2) RNA SS+
3) Icosahedral
4) Fever followed by descending rash
5) Transmitted by aerosol
33yo woman presents with rash on her face that traveled to her arms in recent days. Before rash, pt. had a fever for a couple of days that resolved. Pt. is unsure of her vaccinatio history. Diagnosis? Transmission?
1) Rubella (Togavirus= SS+ RNA virus)
2) Aerosol (unlike the other togaviruses which are transmitted via aerosol)
West Nile Virus: Family? Envelope? Structure? Capsid? Clinical? Transmission?
1) Flavivirus
2) Yes envelope–Flaviflav sends out envelops for his parties
3) RNA SS+ linear
4) Non specific sx or encephalitis (hx is impt)
5) Virus cycle between birds and mosquitoes; clusters of dead crows herald human cases
75yo man from NY brough to ED with fever, ehadache, nasua and muscle ache; confused and tremor in hands. CT and MRI are unrevealing. CSF shows elevated protein, normal glucose and lymphocytosis. Have seen lots of dead cows in town recently. Bug? Transmission?
1) West nile virus ( Flavivirus– SS+RNA)
2) Usually between birds and mosquitos; humans are incidental hosts
Patient from South America presents with hepatitis and jaundice; black vomit. Recently bitten by a mosquito. Possible diagnosis? Family? What kind of mosquito?
1) Yellow Fever
2) Flavivirus (RNA SS+)
3) Aedes
Patient from tropical area with flu-like sx and SEVERE joint/muscle pain. Recently bitten by a mosquito. Possible diagnosis? Family? Complications?
1) Dengue Fever
2) Flavivirus (RNA SS+)
3) If pt. becomes infected with a different serotype, the antibodies from the first rxn can cross link–>immune complexes–>hemorrhage and shock
Major mosquito vector for Yellow Fever and Dengue Fever
Aedes Aegypti
Hep C: Family? Envelope? Structure? Capsid? Presentation? Treatment?
1) Flavivirdae
2) Yes
3) RNA SS+
4) Icosahedral
5) Jaundice acutely; cirrhosis long term
6) Pegylated alpha interferon; ribavirin
Pt presents with fatigue. Received blood transfusion a few years ago and had an episode of jaundice. After confirmation of the likely disease, 1) what drug would you use to treat this man? 2) MOA of drug?
Ribivarin (inhibits IMP dehydrogenase)
Retroviridae: Envelope? Structure? Capsid?
1) Yes ( need an invitation to the retro party)
2) SS+ linear
3) Icosahedral
HTLV: Family? Envelope? Structure? Capsid? Presentation?
1) Retroviridae
2) Yes (invitation to retro party)
3) SS+ RNA
4) Icosahedral
5) White matter lesions on brain and paraventricular gray matter; sensory loss; T-cell leukemia/lymphoma
Where is HTLV 1 endemic to? HTLV2 endemic?
1) Japan and Caribbean
2) Native American
Japanese woman presents with stiffness in her legs. Lesions of white matter and paraventricular gray matter on MRI. Diagnosis? Family?
1) HTLV 1 (probably not 2– 2 is endemic to native america)
2) Retroviridae
Delta Virus (Hep D): Envelope? Structure? Capsid? Presentation? Diagnosis? Treatment?
1) YES
2) RNA SS- circular
3) Uncertain
4) Hepatitis
5) delta antigen detection
6) Alpha IFN
Patient, chronic drug user, with hx of HBV presents with severe signs of chronic hepatitis. What other condition may this patient have? Treatment?
1) Hep D (SS- circular; delta)
2) Alpha IFN
Coronavirus: Envelope? Structure? Capsid? Presentation? Why called corona?
1) Yes (need invitation to party with corona)
2) SS+ linear
3) Icosahedral
4) common cold
5) Club shaped projections on envelope (glycoprotein spikes)
Child presents with runny nose and common cold. It is not a rhinovirus. What is the second most common cause of cold?
1) Corona
Yes envelope, SS+ linear RNA virus
Bunyavirus: Envelope? Structure? Capsid? Transmission?
1) Yes envelope (bunnies send messages)
2) SS- Circular RNA
3) UNCERTAIN
4) Rodents to mosquitos
4 types of Bunyavirus? Structure?
1) California encephalitis
2) Sandfly/Rift Valley fevers
3) Crimean-congo hemorrhagic fever
4) Hantavirus
5) SS- circular RNA
California encephalitis Virus: Family? Envelope? Structure? Capsid? Clinical? Transmission?
1) Bunya
2) Yes (bunnies send letters)
3) SS- Circular RNA
4) Encephalitis
5) Forest rodents–>humans via mosquitos–>direct damage to neurons
Higher risk in Midwest Forests
10yo pt. presents with severe headache, + babinski, tremors, confusion. Nroaml glucose and protein but PMN and Mononuclear cells on CSF. Illness acquired fro mosquitos near Michigan forest. Bug? Transmission?
1) California Encephalitis Virus (RNA SS- circular)
2) Rodents to mosquitos to humans
Hantavirus: Family? Envelope? Structure? Capsid? Clinical? Transmission?
1) Bunya
2) Yes envelope (bunnies send letters)
3) unclear
4) Deer mice; fever; vomiting; cyanotic; tachypneic; respiratory failure; interstitial pulmonary edema
5) NO ARTHROPOD
23yo M, from arizona, presents with cyanosis, hypotension, tachypnia. Interstitial edema is evident on CXR. Pt. develops respiratory failure and dies the next day. Bug? Class? Transmission?
1) Hantavirus
2) Bunya (SS- circular)
3) Rodents (no arthropods)!
Arenaviruses: Envelope? Structure? Capsid?
1) Yes
2) SS- Circular
3) helical
Lassa Virus: Family? Envelope? Structure? Capsid? Clinical? Transmission?
1) Arenavirus
2) Yes envelope (send messages to “Las” Vegas)
3) SS- circular RNA
4) Helical
5) hemorrhagic fever
6) WEST AFRICA; Rodents
34yo woman, visit to Nigeria, fever, headache, nausea, diarrhea. Pericardial effusion; GI bleed. Possible disease? transmission?
Lassa Virus (RNA SS-; Arenavirus)
Rodents
Presents with hemorrhagic fever
Orthomyxovirdae influ: Envelope? Structure? Capsid? Clinical? Transmission? Associated syndrome when treated with aspirin?
1) Yes
2) SS- linear (8 segments– MYX up the types of flus)
3) Helical
4) Altered mental status and seizures; RLQ pain; epistaxis; family member with similar
5) Aerosol
6) Reyes syndrome
10yo presents with altered mental status and seizures. He has fever, myalgia, and cough. His mother said she had the same thing last week. She gave her son aspirin for his condition. Bug? Family? other?
1) Flu
2) Orthomix ss- segmented
3) Reye’s syndrome! Aspirin caused this syndrome
Paramyxovirus: Envelope? Structure? Capsid? Bugs (4)
1) Yes
2) SS- linear
3) helical
4) Parainfluenza; RSV; measles; Mumps
Baby girl brought to ED with high fever, nasal discharge, and barking cough. Cough disappeared when pt went outside in the cold. Dx?
Croup (Parainfluenza)
Baby with previous illness returns to hospital 2 days later with cough fever and wheezing. CXR reveals hyperinflated lungs with infiltrates. Possible dx? Treatment? Characteristic cells? Why?
RSV
Ribavirin
Syncytial cells dt viral fusion F surface proteins
16yo testicular pain. Tender and enlarged over last day. Swollen parotid glands. Muscle aches. Dx? Labs?
1) Mumps (URT)
2) Elevated serum amylase generally
11month old presents with rash, fever, conjunctivitis and runny nose. Rashes spread from hairline to trunk and then to extremities; bright red and raised. Dx? Other sx? complications?
Measles
Koplik spots followed by rash; encephalitis
3) Can lead to subacute sclerosing panencephalitis (neuro sx of measles)
Protein common to all Paramyxoviridae?
Viral Fusion (F) protein–>causes infected cells to produce multinucleated giant cells
Rabies: Envelope? Structure? Capsid? Pathobio?clinical? Histology?
1) Yes
2) RNA SS-
3) helical
4) Glycoprotein spikes bind to ACh receptors and are vital for rabies virulence
5) Negri bodies
Graduate student bitten by wild dog. Few months later begins to have trouble swallowing; hallucinations; sensitivity to bright light. Dies. DX? Pathobio? Histology?
1) Rabies duh
2) Glycoprotein spikes bind to ACh receptors– vital for virulence of rabies
3) NEGRI BODIES
Filovirus (Ebola, Marburg): Envelope? Structure? Capsid? Clinical? resevoir?
1) yes
2) SS- linear
3) helical
4) hemorrhagic fever
5) In marburg is monkeys; unknown in ebola (Subsaharian Africa)
Negative Strand RNA viruses
Always Bring Polymerase Or Fail Replication
Arenavirus
Bunyavirus
Paramyxovirus
Orthomyxovirus
Filoviruses
Rhabdovirus
Segmented RNA viruses
BOAR
Bunyavirus
Orthomyxovirus
Arenavirus
Reoviruses
Most important cause of infantile gastroenteritis?
Rotavirus
Medication against the F protein?
Palivizumab
paramyxovirus…
What does a high HBeAg tell us?
Indicative of ACTIVE viral replication– highly transmissible
Catalase positive Coagulase positive? Complication?
S. Aureus can cause toxis SS
Beta hemolytics: Group A?
Group B?
Sensitive or resistent to?
A=S. pyogenes; bacitracin sensitive
B= S. agalactiae; bacitracin resistant
Catalase positive; coag negative (2)– what are they resistant or sensitive to?
1) Staph epi; novobiocin sensitive
2) S. saprophyticus; novobiocin resistant
Alpha hemolytics? (2) Sensitivity or resistance?
1) S. pneumonia; optochin sensitive; capsule
2) S. viridans; optochin resistant; no capsule
Gamma hemolytics: group D? Nonenterococcus?
1a) E. faecalis; growth in bile and NaCl
2) Nonenteroccus; growth in bile but NOT nacl
5 gram positive rods
1) Clostridium (anaerobic)
2) Cornebacterium
3) Listeria
4) Bacillus
5) mycobacterium
Important surface antigen in gram positive bacteria?
Techoic acid
Quellung reaction? (2 examples)
diagnositc test in which specific antiserum causes the capsule to swell (s pneumoniae; h flu)
Componenets of LPS
Lipid A= endotoxin component of gm- that causes fever and shock
Polysaccharide= important surafce antigen
Stap Aureus: Virulence factor? Clinical presentations (3)?
1) Protein A binds Fc-IgG region inhibiting complement fixation and phagocytosis
2) a) Skin infections (scalded skin syndrome)
b) Food poisoning– heat stabile toxin
c) TSS= TSST- 1 is a superantigen which promotes excess release of cytokins–>hypotensive shock
Young women develops high fever 2 days after menses. She used tampons. Dizziness, hypotension, myalgias, and diffuse chest rash ensue. Desquamation of palms is observed. Describe pathophys of this bug? Class of drugs to treat?
1) S. aureus–> TSS
2) Superantigen binds to MHCII and TCR resulting in polyclonal Tcell activation
3) block IL-1 and TNF
Virulence factor of S. aureus?
Protein A which binds up Fc portion of IgG–>blocks complement fixation
IV drug user presens with fever and signs of heart failure. Echo reveals tricuspid vegetations. Patient put on penicillinase resistant penicillin and improves. Bug? pathophys? Who else is susceptible to this?
1) S. aureus infection–> acute endocarditis on tricuspid valve particularly
2) Protein A binds Fc portion of IgG
3) CGD patients (impaired neutrophil function)
What is the leading cause of osteomyelitis in children and adults?
S. aureus
What class of drugs is MRSA resistant to?
Beta lactams
S. epidermitis: Cat? Coag? clinical? Virulence?
1) Gm+ cat+ coag-
2) infects prosthetic devices and IV catheters
3) Produces ADHERENT BIOFILMS
Patient recently in hospital for chemo. Has an IV catheter. Develops fever; erythema and tenderness at IV site. Pathophys of organism?
1) Staph Epi
2) Produces adherent biofilms
Strep pneumo: Describe? Clinical? Virulence?
1) Gm+; cat-; alpha hemolytic; optochin sensitive
2) Lobar pneumonia
3) No virulence without capsule; also have IgA PROTEASE
S. saprophyticus: Description? Clinical? Virulence?
1) Cat+, coag-
2) UTI; cystitis
3) nothing important
Sexually active woman develops dysuria, pyuria and fever. Cultures show gm+, cat+ coag-. What should patient be put on? what does patient have?
1) Staph saprophyticus
2) TMP-SMX
Strep pyogenes: Description? Clinical? Virulence?
1) Group A beta hemolytic; bacitracin sensitive
2) Pyogenic= pharyngitis
Toxigenic= scarlet fever, TSS
Immunologic= rheumatic fever
3) M protein resists phagocytosis
Jones criteria for Rheumatic Fever
1) Joints
2) O (heart) carditis
3) Nodules
4) Erythema marginatum
5) Syndenhams chorea= jerky movement of hands and feet
8yo with fever and skin rash around lips and arms. Rash appears pustular with yellow crusts. Cultures from impetigo show gm+ cocci; beta hemolytic. Virulence?
M protein resists phagocytosis–> can give rise to rheumatic fever
Young girl has rough appearing rash on trunk and neck that has spread to arms. Palms and soles are spared. Fever and sore throat. ASO+. Bug? Condition?
1) Strep pyogenes; gm+ group A beta hemolytic; bacitracin sensitive
2) Scarlet fever– rash starts at trunk and moves outward; desquamation of hands and soles after rash subsides
Adolescent presents complaining of brownish urine. Two weeks earlier had sore throat that resolved. High BP and slight swelling around eyes. Elevated Bun and Creatinin, ASO+; What would you expect to see in complement? Urinalysis? EM? Virulence factor?
1) decreased C3 levels
2) RBC casts and protein; hematuria;
3) Subepithelialm humps
Possible endocarditis pathophys?
Valves damaged by rheumatic fever (strep pyogenes) makes the valves susceptible to enterococci or Viridans–>endocarditis
Strep Agalactiae: Description? Clinical? Virulence?
1) Gm+, Group B beta hemolytic; bacitracin resistant
2) Baby develops seizures, poor feeding and fever; most common cause of meningitis in newborn
3) Produces CAMP factor which
Baby develops seizure; poor feeding; fever. Prolonged labor. Bug? Virulence factor?
1) Strep agalactiae; Gm+ group B beta hemolytics; bacitracin resistant
2) CAMP which enlarges area of hemolysis by S. aureus
Most common cause of neonatal meningitis?
Strep Agalactiae
Top 3 causes of neonatal meningitis?
1) Strep agalactiae
2) Ecoli
3) Listeria
Enterococcus Faecalis: Description? Clinical? Resistant to what drug? Treatment?
1) Gm+; can be any of the hemolytics; grows in Bile AND NaCL
2) UTI; biliary tract infection
3) RESISTANT TO CEPHALOSPORINS (coccus are cocks bec they are resistant to vanco)
** **4) Vancomycin (d-ala d-ala)
Old man develops UTI after admission to hospital. Receiving cephalosporin for unrelated infection. Bug?
Enterococcus faecelis– second most common cause of nosocomial infection and RESISTANT TO CEPAHLOSPORIN
Strep Bovis: Description? Clinical? Virulence?
1) Gm+; nonenterococus; alpha beta or gamma; grows in BILE only
2) Subacute bacterial endocarditis in colon cancer patients; bacteremia (Bovis in blood= cancer in colon)
3) Invades through GI lesions; may signal COLONIC CARCINOMA OR IBD
Elderly man develops low grade fever and signs of endocarditis over 2 weeks. Bug grows on Bile but not NaCl. Bug? What should doctor be concerned about?
1) Strep bovis
2) Colon cancer– bug travels through lesions in the GI tract
