VIRAL GASTROENTERITIS VIRAL GASTROENTERITIS. Viruses associated with gastroenteritis Etiologic...
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Transcript of VIRAL GASTROENTERITIS VIRAL GASTROENTERITIS. Viruses associated with gastroenteritis Etiologic...
VIRAL GASTROENTERITIS
Viruses associated with gastroenteritis
Etiologic agents in severe diarrheal illnesses requiring H of infants & young children Other viruses;
Coronaviruses ,Toroviruses & Enteroviruses
Epidemiology
Distribution ; Worldwide in poor hygiene, overcrowding, and
poverty
Age ; Infants & young>>Older children
Transmission ; Faecal-oral route
Season ; Winter months
Endemic inf ; Gp A rota & adeno 40,41
Epidemic inf ; Norovirus
VGE
Clinical Features VGE
IP ;ShortSymptoms:
D, V, Fever & abdominal cramps
Dehydration with Na Life threateningWinter vomiting disease:
Vomiting > Diarrhoea Calicivirus
VGE
Cell culture: [c/c]
Fastidious growing poorly not used
Electron microscopy: [EM]
Catch all techMany disadvantages not used
Specific test:ELISA for detection of viral ags in stool
[rota , adeno , astro & caliciviruses]
Lab diagnosis
VGE
Treatment:Rehydration
Prevention: Sanitation & hygiene measures
No vaccines except for rotavirus
Management
ROTAVIRUSFamily:
Reoviridae [Respiratory& Enteric Orphan]
Description:11 segments dsRNADouble-layered icosahedralNonenveloped
~ 70 nmRNA – dependent RNA polymerase
7 groups [A-G]----- GpA most common
EpidemiologyRota
Rota
Spread:Faecal-oral route
Age: all age groupsSymptomatic inf ;
6 -24 M
Peak ; Winter months
Inf ; Endemic
RotaRota
Pathogenesis
Clinical featuresRota
Rota
Intestinal inf:Infants & young children
gastroenteritis or infantile GE IP = 1-2 dsWatery, nonbloody D,V & FDehydrationOutcomes Vary
~1/2 of all GE cases AdmissionIn developed count. Mortality is lowIn developing count. Mortality is sig
Deaths reported
Clinical featuresRota
Rota
Intestinal inf:Infants & young children GEOlder children+ adults asymptomaticImmuno ed hosts chronic D
Extra-intestinal inf:Encephalitis small n.
Rota
Rota
Sample; stool Immunoassay Most used
ELISA & latex agglutination (gp A rotavirus Ag)
EMGel electrophoresisRT.PCRCell culture
Diagnosis
Rota
Rota
ManagementTreatment:
Rehydration
Prevention:Sanitation & hygiene measuresVaccine; LAV, oral
Rotashield ( withdrawn)RotarixRotaTeq
ENTERIC ADENOVIRUSESFamily: AdenoviridaeDescription:
Nonenveloped, icosahedral,dsDNAOnly V with a fiber protruding from each of
the vertices of the capsid Fiber Attachment
Hemagglutinin
Type-specific ag
ENTERIC ADENOVIRUSESClassification:
Adenovirus 6 subgenera[A-F]
51 serotypes Grow in C/C
Enteric adenoviruses Subgenus F 40&41serotypes
Fastidious
ENTERIC ADENOVIRUSESClinical feature:
Longer IP Less severe than rotavirusProlonged illness
Diagnosis:Ag detection in stool by ELISA
CalicivirusesFamily ; Caliciviridae [Calyx =cup]
Description :NonenvelopedssRNA,+ve polarityIcosahedral
Two morphologic typesTypical caliciviruses (Sapoviruses)Small Rounded Structured Viruses . (Noroviruses)
EpidemiologyFaecal-oral route [water, shellfish]Outbreaks of GE in schools, camps &cruiseAll age gps
Clinical featuresChildren vomiting [projectile]Adults diarrhea
DiagnosisViral Ag in stool by ELISA
NOROVIRUS(Norwalk virus)
Astroviruses
Family; Astroviridae [astro= a star]
Description:NonenvelopedssRNA,+ve polarityIcosahedral
8 serotypes
AstrovirusesClinical featuresMild GEOutbreak of diarrhea <5 ys
Lab. Diagnosis:Ag detection in stool by ELISA
عنه الله رضي هريره أبي عن: قال وسلم عليه الله صلي الله رسول أن
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الرحمن إلي : حبيبتان
سبحان الله وبحمده ,
سبحان الله
{العظيم