most common viral cause of bronchiolitis
RSV( and HMPV)
has surface protein, F, that fuses w/cell membrane @ neutral pH
replicates in ciliated epithelial cells lining respiratory tract
rhinovirus attaches via_____to target cell
induces the production of ______ and ______ to induce vasodilation and inflammation
rhinovirus attaches via ICAM1 to target cell
induces the prodcution of bradykinin and IL8 to induce vasodilation and inflammation
complications of flu?
increases risk of s.aureus pneumonia and pneumonia in general
FEVER, HA, MYALGIA, MALAISE
+ resp symptoms(cough, sore throat)
most susceptible population for bronchiolitis?
neonates/bebes are most at risk;
any abnormal/birthing complications/defects will predispose the child to bronchiolitis;
monoclonal Ab prophylaxis for RSV
give to premies/bebes @ high risk
most common viral cause of croup
CPE for influenza
kills ciliated epithelium in throat
internal ribosome entry sites
regions which ribosomes bind to on rhinovirus mRNA to initiate translation
why does rhinovirus have nasal specificity
grows better at 33/34C than 37C; colder temps
peak season for parainfluenza infections?
FALL OR LATE SPRING
like the common cold...
hallmark of croups?
narrowing of subglottic region
duration of common cold
peak viral growth?
~a week(5-7 days)
peak growth @ ~day 3
presentation of rhinovirus
nasal mucosa ifection: sneezing, rhinitis, nasal obstruction,sore throat
describe pathogenesis of RSV
infects nasopharyns(turbinates) then spreads to lower respiratory tract
causes necrosis of bronchiolar epithelium and destroys epithelial cells
inflammation, mucous, cell debris clog bronchioles
peak season for rhinovirus
FALL, LATE SPRING
Relavent respiratory viruses(transmited via respiratory droplets)
peak season for bronchiolitis
october-may - Patel
most susceptible to flu?
very young and very old
still nasty for anyone
most common viral cause of common cold
antigenic drift vs shift for influenza genome
shift is combo of 2 influenza genomes = pandemic
drift is minor changes to genome through mutation as it moves through population
describe the genome of influenza
what determines influenza strain?
segmente genome(8 segments); RNA(-)
HA, NA types determine influenza strain
describe entry/replication of influenza
HA binds sialic acid on surface
- Enters in endosome
- endosome acidifies, changing conformation of HA to fuse with endosome membrane;
M2 dependent uncoating
- RNA heads to nucleus for replication/transcription
where does influenza virus replicate w/in the cell?
2nd leading cause of childhood hospitalizations for acute respiratory infections
most common/suscpetible age for croups
pre-school age; dont see it much after age 6
SARS - ACE2; ciliated epithelium
MERS - DPP4; alveorlar