SketchyMicro: Viruses Flashcards
Piconavirus: 3 main features
Piconaviruses:
- positive sense: meaning the RNA is directly translated into proteins
- RNA virus
- naked
3 main subgroups of piconaviruses
Piconaviruses: positive sense RNA viruses w/o capsules (naked)
ABC
- A for Hepatitis A
- B for birds = Enterovirus
- C for common cold = Rhinovirus
Main manifestation of the three classes of piconoviruses
(a) Hep A
(b) Enterovirus
(c) Rhinovirus
(a) Hep A => anicteric acute febrile self limited
(b) Enterovirus = MC cause of aspetic (aka nothing grows on gram stain b/c there’s no bacteria) meningitis
(c) Rhinovirus => common cold
MC cause of aspetic meningitis
Aspetic meningitis = viral meningities, MC cause = enterococcus species = poliovirus, coxsackie A and B, echovirus
Called aseptic b/c the gram stain doesn’t grow anything (b/c it’s viral not bacterial)
Where does the polio virus replicated?
(a) Duration of latency period
Polio virus replicated in Peyers patches of the GI tract
(a) Remains latent for about 2-3 weeks, then infects anterior horn cells of the spinal cord
Differentiate the 2 vaccines for poliomyelitis
- Salk = inactivated, killed vaccine given intramuscularly
- IM so bypass Peyer’s patches => mostly IgG not IgA - Sabin = oral live attenuated vaccine- gives both IgA and IgG but can shed in feces and revert to infectious strain
- rare but this is why we don’t use it in the US (we use Salk)
Where does the poliovirus infect to cause symptoms?
(a) Clinical presentation
(b) Cause of death
Poliovirus infects the anterior horn cells of the spinal cord
(a) Ascending asymmetric paralysis
(b) Paralysis rises to diaphragm => respiratory insufficiency
Compare and contrast coxsackie A and B viruses
Both coxsackie viruses are enteroviruses, which are picornaviruses = positive sense RNA naked viruses
A => hand-foot-mouth disease, red vesicular rash, and aseptic meningitis (like the other enteroviruses)
B => dilated cardiomyopathy and Devil’s grip
Name 3 rashes that involve the hands and feet
- Hand-foot-mouth disease = Cocksackie A
- Syphilis
- Rickettsia Ricketsia
Buzzwords
(a) Devil’s grip
(b) Child immigrant p/w descending rash and lymphadenopathy
(a) Cocksackie B caused syndrome of severe unilateral CP that makes it hard to breathe
(b) Rubella = German measles
Which of the picornaviruses is acid labile?
3 subgroups of picornaviruses = ABC
- A: Hepatitis A
- B: Birds = Enterococcus
- C: Common cold = rhinovirus
Rhinovirus is the only acid labile one of the three => can’t survive gastric acid => not fecal/oral transmitted, instead by fomites and respiratory droplets
While Hep A and enterococcus are acid stable => transmitted fecal/oral
What group of virus causes
(a) Rhinovirus
(b) Cruise ship diarrhea
(c) Dengue fever
Viral group
(a) Rhinovirus = picornavirus- positive sense RNA naked virus
(b) Cruise ship diarrhea = Norwalk virus = Calicivirus = ssRNA naked positive sense
(c) Dengue fever = flavivirus
What group of viruses causes
(a) Yellow fever
(b) Rubella
(c) Hepatitis A
Viral group
(a) Yellow fever = flavivirus
(b) Rubella (German measles) = togavirus
(c) Hepatitis A = picornavirus
What group of viruses causes
(a) West Nile Virus
(b) SARS
Viral group
(a) West nile = Flavivirus
(b) SARS = coronavirus
Explain why rhinovirus infects the location it does
Rhinovirus prefers cooler temps (33 C) as in colder than body temp, so likes the upper respiratory tract where air comes in and is colder
Why don’t we have a vaccine for the
(a) Common cold
(b) Hepatitis C
(a) Ummm b/c there’s literally 113 serotypes of rhinovirus- can’t cover for all of them
(b) Hep C envelop proteins have a ton of antigen variability b/c their virion encoded RNA polymerase lacks 3’ to 5’ exonuclease proofreading activity
MC mode of transmission of Hepatitis A
(a) Underdeveloped countries
(b) US
Hepatitis A
(a) Contaminated water in underdeveloped countries
(b) US- uncooked shellfish
Smoker suddenly develops aversion to smoking
Buzzword for Hepatitis A infection
Describe the clinical presentation of Hepatitis A
(a) Duration
Usually asymptomatic (esp in children), but can be acute febrile illness w/ RUQ pain and jaundice (jaundice esp in adults)
Lasts about 1 mo without a chronic state! No carrier/chronic state
Who gets the Hep A vaccine?
MSM, travel to endemic area, other chronic liver disease
Viral group
(a) Hepatitis A
(b) Hepatitis C
Viral group
a) Hepatitis A = picornavirus
(b) Hepatitis C = flavivirus (also Dengue, West Nile, Yellow fever
Break bone fever
Break bone fever = Dengue fever, infects bone marrow and can cause thrombocytopenia
Which flavivirus has a vaccine?
Live attenuated vaccine available for yellow fever
-not Dengue or West Nile Virus
Differentiate clinical presentation of Dengue vs. Yellow fever
Dengue fever- break bone fever (infects bone marrow) => thrombocytopenia, hemorrhagic fever, high risk renal failure
Yellow fever- jaundice, back ache, bloody diarrhea
Both by the same species of mosquito