ID 12 Flashcards
rhabdovirus structure
enveloped, single strand, negative sense, helical
filoviruses
Ebola
Marburg hemorrhagic fever
filovirus structure
*enveloped
SS, negative sense, linear, helical
Arena viruses…
LCMV - lymphocytic choriomeningitis virus
Lassa fever encephalitis
Lassa fever encephalitis transmission
spread by rodents
arenavirus structure
enveloped, SS positive or negative, circular, 2 segments, helical capsid
Bunyaviruses
1) california encephalitis
2) Sandfly/Rift Valley fevers
3) Crimean-Congo hemorrhagic fever
4) Hantavirus-
Bunyavirus structure
*enveloped
SS negative sense, circular, 3 segments, helical capsid
Delta virus structure
*enveloped
SS negative sense, circular
segmented viruses
1) bunyaviruses
2) orthomyxoviruses
3) arena viruses
4) reoviruses
picornavirus memory trick
picoRNAvirus = small RNA virus
picornavirus characteristics
1) all enteroviruses (fecal-oral) except rhinovirus
2) RNA is translated into 1 large polypeptide that is cleaved by proteases into functional viral proteins.
rhinovirus characteristics
1) over 100 serotypes
2) acid labile (explains why it doesn’t affect GI tract)
yellow fever virus vector
Aedes mosquito
yellow fever reservoir
monkeys or humans
councilman bodies
eosinophilic apoptotic globules
rotavirus season
winter
rotavirus pathophys
villous destruction with atrophy leads to decreased absorption of sodium and loss of potassium
most common pathogens with flu superinfection
1) s aureus
2) s pneumonia
3) h flu
other name for genetic shift
antigenic shift
genetic shift causes…
pandemics
other name for genetic drift
antigenic drift
cause of genetic drift
random mutation in hemagglutinin or neuraminidase genes
rubella presentation and rash characteristic
1) fever
2) post auricular or other lymphadenopathy
3) arthralgia
4) fine, confluent rash starting on face and spreading centrifugally to involve trunk and extremities.
croup cough description
seal-like barking cough + inspiratory stridor
shared characteristics of paramyxoviruses…
1) F, fusion protein
Croup other name
acute laryngotracheobronchitis
croup on CXR
narrowing of upper trachea and sub glottis leads to characteristic steeple sign
croup sequela..
Can result in pulses paradoxus secondary to upper airway obstruction.
measles prsentation
1) prodromal fever with cough
2) coryza
3) conjunctivitis
4) koplik soos
5) followed 1-2 days later by a maculopapular rash starting at head/neck and spreading downward
Warthin-Finkeldey description
Giant cells (fused lymphocytes) in a background of paracortical hyperplasia.
koplik spot description
bright red spots with blue-white center on buccal mucosa
sequela of measles…
1) SSPE
2) encephalitis
3) giant cell pneumonia (rarely, in immunosuppressed)
treatment for measles
Vitamin A can reduce morbidity and mortality, especially in malnourished
mumps symptoms
Parotitis
Orchitis
aseptic meningitis
pancreatitis
negri body description
cytoplasmic inclusions commonly found in Purkinje cells of cerebellum and in hippocampal neurons
classic example of passive-active immunity…
rabies
postexposure prophylaxis for rabis
1) wound cleaning + immunization w/ killed vaccine + rabies immunoglobulin
rabies pathophys
travels retrograde to CNS after binding to ACh receptors
rabies disease progression
fever, malaise –> agitation, photophobia, hydrophobia, hyper salivation –> paralysis, coma –> death
common sources of rabies infection
More commonly from bat, raccoon, and skunk bites than from dog bites in the US. Aerosol transmission in bat caves also possible.
what does ebola target?
endothelial cells + phagocytes + hepatocytes
ebola virus pathogenesis
incubation period of up to 21 days then abrupt onset of flu-like symptoms + diarrhea/vomiting + high fever + myalgia. Then can progress to DIC –> diffuse hemorrhaging –> shock.
ebola diagnosis
RT-PCR within 48 hours of symptom onset
ebola transmission
1) direct contact with bodily fluids OR fomites (dead bodies) OR infected bats or primates.
2) high incidence of nosocomial infection
treatment for ebola?
supportive. strict isolation and barrier practices for healthcare providers.
hepatitis viruses lacking envelope? characteristics?
HAV and HEV. They are not destroyed by the gut. Vowels hit your bowels.
HBV lifecycle
enters nucleus –> polymerase completes partial dsDNA –> host RNA polymerase transcribes mRNA from viral DNA to make viral proteins –> DNA polymerase reverse transcribes viral RNA to DNA, which is the genome of the progeny virus.
HCV genetics
lacks 3’-5’ exonuclease activity. This is what causes variation in antigenic structures of HCV envelope proteins. Host antibody production lags behind production of new mutants strains of HCV.
Common sources of HAV…
1) shellfish
2) travelers
3) day care
Hantavirus causes…
hemorrhagic fever + pneumonia
