Whitt: Gi viruses Flashcards
“most important agent of severe Diarrheal illness in infants and young children worldwide”
Rotovirus-(reoviridae)
followed by ETEC, UNKNOWN, Adenovirus
reoviridae stands for
respiratory
enteric
orphan
NON-ENVELOPED particles
2-3 concentric icosahedral capsids
rotavirus
rotavirus characters
non enveloped
2-3 concentric icosahedral capsids
rotavirus G
VP7-neutralization antigen
rotavirus P
VP4-neutralization antigen
rotavirus: only 4 G-P combos cause 90% of the Dz
* basis of the success of the vaccine
G1-P8
G2-P4
G3-P8
G4-P8
replication cycle of rotorviruses
- taken up by endocytosis (capsid prots are processed either in the gut or in the lysosome)-forms infectious subviral particle
- core enzymes-begin synthesizing mRNAs-asymettric only 10-12 +strands
- capped + strands to “assortment complexes
- negative strands made
- dsRNA genome complete
- lysis and release
asembly of rotoviruses occurs entirely within the
cytoplasm in cytoplasmic viroplasms (viral factory)
calciviridae
noroviruses
foodborne epidemic acute gastroenteritis in older children and adults
noroviruses (calciviridae)
non-enveloped, non-segmented
+ strand RNA virus
Norovirus
“hospitalized with D in first 2 years of life”
rotovirus
community based outbreaks in older school aged children and adults-non bacterial D
norovirus
winter vomiting disease
norovirus
transmission of roto-noro viruses
fecal oral mainly
*extremely stable in the environment
this bug outbreaks are located to a single source
1. contaminated food
(icing, oysters, salads)
2. cruise ships and nursing homes
norovirus
this virus can be airborne
norovirus
clinical course for noro and rotoviruses
N/V/D/F
leading to dehydration
noro and rotoviruses initiallty infect +_+__
tips of villi in the small bowel
NORO and ROTO role in Diarrheal disease
do not activate cAMP-unlike cholera toxin
- they do cause loss of villious cells-> FUNCTIONAL ALTERATIONS IN SMALL/LARGE intestines
- >
most important factor for protection agfaisnt rreinfection by both rota and noroviruses is….
local (intestinal) immunity
antibodies to rotaviruses
obtained early in life
ab’s to noroviruses
acquired gradually in childhood and icnrease steadily over life time
two vaccines for rotoviruses
rotateq
rotarix
rotateq
- Approved for sale in U.S. by FDA in February, 2006
- Pentavalent bovine-human reassortant viruses (serotypes G1-G4 and P8) -Live, attenuated vaccine given orally at 2, 4, and 6 months
rotarix
- Human-derived monovalent (G1, P8), live, attenuated vaccine
- Administered orally in two doses starting at 6-weeks of age
norovirus vaccines
none
non-enveloped, icosahedra;, single stranded, +sense RNA
STAR LIKE APPEANCE
Astroviruses
after reoviruses-second most common cause of childhood D in children <1 year old
Astroviruses
whatr % of 5-10 year olds have Ab’s to astroviriuses
80%
spread by astroviruses
oral-fecal route
peak incidence of astrovrisues
winter-self limiting
vaccine for astroviruses
not available
picoviridae
enteroviruses
small icosahedral nonenveloped + sense RNA viruses
enteroviruses
pico=
small-RNA virus
name the enteroviruses
picornoviridae
polio
enterovirus
cocksackie A and B
echoviruses
causes flaccid paralysis
polioviruses
ECHO virus stands for
enteric, cytotoxic, human orphan
also an enterovirus-like virus
hepatitis A
what differentiates enteroviruses from rhinoviruses
a. acid stability
b. replicaiton at 37 degrees
* enteroviruses can do both of these thangs
spread of enteroviruses
fecal-oral route
humans only reservoir
initially replicate in the lymph tissue of URT and Gut
enteroviruses
enteroviruses can be cultured from
throat swabs
viremia with enteroviruses causes
Spinal cord and brain infectin
myocardium
skin
meninges
how quick is enteroviruses in stool and throat
10 days in stool and throat
blood in 9
csf in 14
vaccines for enteroviruses
polio only
adenoviridae
adenovirus
large, non enveloped, linear dsDNA
adenovirus
two ADENO stereotypes associated with gastroenteritis
40 and 41