Micro - Adenovirus Flashcards
Key characteristic of adenovirus
Respiratory, ocular, GI infections
Which AdV infection occurs in isolation of the other two?
GI infection (can have pharyngotracheal infections but GI serotypes don't cause respiratory/ocular sx)
AdV is (enveloped, nonenveloped) (RNA+, RNA-, DNA)
Nonenveloped DNA
only AdV and rhinovirus aren’t enveloped
Seasonality of AdV
Winter to spring
like flu and hPIV3
Consequence of AdV being nonenveloped?
Resistant to detergent, low pH of stomach, alcohol, and can live for long time outside body in water
Transmission of AdV
Water droplets via inhalation, fecal-oral route, direct inoculation
AdV 4-7
Linked to ARDS in military recruits; only strains for which there is a vaccine
AdV 36-37
May cause obesity
AdV 40-41
Linked to GI infections
Eye + nose symptoms =
AdV!!!
What is unique about recovery from AdV infection?
AdV can persist in lymphoid tissues, i.e. tonsils, ADENOids, Peyer’s patches for 6-18 months
What kind of tissue damage does AdV cause?
Epithelial cell necrosis and inflammation
2 virulence factors of AdV
- Capsid penton protein - attachment protein responsible for toxic effects
- Hexon protein - elicits complement-fixing Abs but doesn’t confer immunity, just aids in testing
What is significant about penton-specific Abs?
Confer immunity for life + can be used diagnostically to determine serotype of AdV
Sx of respiratory AdV infx?
Fever, cough, sore throat
Sx of ocular AdV infx?
Sand in eyes + runny nose
Sx of GI AdV infx?
N/V
Diarrhea
How to dx AdV
- Culture
- Penton-specfic Abs = serotype
- Complement fixation assay for hexon-specific Abs = whether it’s AdV
- Hemagglutinin inhibition assay
Why do hemagglutinin inhibition assay for AdV?
Some serotypes have penton proteins that can cause RBCs to clump
Tx of AdV?
Supportive
Live attenuated vaccin of AdV 4-7 to prevent ARD in military recruits only
Who does AdV most commonly infect?
Young children
Where does AdV replication occur?
Nucleus, initially at site of infx (pharynx, conjunctivae, intestine)
(same as influenza)
What defines an AdV serotype?
Type of penton protein
Where would one contract AdV that causes conjunctivitis?
Inadequately chlorinated swimming pool
Who gets GI infection from AdV?
Kids
Where would one contract AdV that causes epidemic keratoconjunctivitis?
Contaminated eye drops
Who is at greatest risk for respiratory illness caused by AdV?
Children < 3 yo
Sore throat + inflamed eye =
Pharyngoconjunctival fever
AdV is second most common cause of:
GI tract infx in kids, behind rotavirus
Characteristic of AdV in culture?
Severe cytopathic effects on cells within 2-5 days
Why is it difficult to determine AdV as cause of infection?
It can persist for months, so detection of AdV doesn’t necessarily mean it’s the cause of current infection
What is required to etermine AdV as cause of infection?
Comparison of acute vs. convalescent serum with titer 4x higher in convalescent serum
How is AdV vaccine formulated?
Enveloped so it’s released slowly from GI tract to cause subclinical infection so immunity is built
