Osmosis High-Yield Notes
This Osmosis High-Yield Note provides an overview of Reoviruses essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Reoviruses:
Chapter 2 Acyanotic Defects NOTES REOVIRUSES MICROBE OVERVIEW ▪ Rotavirus: most important Reovirus in clinical practice Genetic Material ▪ RNA viruses with segmented double stranded linear RNA Morphology ▪ Encapsulated (icosahedral capsid) ▪ Nonenveloped Replication/multiplication ▪ Replicates in cytoplasm ROTAVIRUS osms.it/rotavirus PATHOLOGY & CAUSES ▪ A major cause of acute diarrhea, especially in children ▫ Most important cause of severe gastroenteritis in infants, young children worldwide ▪ Short incubation period ▫ ↓ activity of brush-border enzymes (such as maltase, lactase) → malabsorption of nutrients → presence of reducing substances in stools → osmotic diarrhea ▫ Direct effects of enterotoxin nonstructural protein 4 (NSP4) on gastrointestinal mucosa (apoptosis of enterocytes) ▫ Activation of enteric nervous system → ↓ absorption of Na+, loss of K+ CAUSES ▪ Transmission by fecal-oral route (ingestion of water/food contaminated by stools) ▫ Spreads easily; minimal infective dose (10 viral particles) RISK FACTORS ▪ Age ▫ Usually affects children between 6–24 months of age ▪ Cooler months in temperate climates ▪ Hospitalization, long term care facilities, day care centers, kindergartens, college dormitories ▪ Immunodeﬁciency ▪ Non-immunized status COMPLICATIONS ▪ Secondary lactase deﬁciency ▪ Severe dehydration ▫ Shock, multisystem failure ▪ Central nervous system complications ▫ Seizures, encephalopathy ▪ Persistent gastroparesis, diarrhea ▪ Necrotizing enterocolitis ▪ Intussusception ▪ Biliary atresia ▪ Can be fatal OSMOSIS.ORG 499
SIGNS & SYMPTOMS ▪ Average duration: 8 days ▪ Children: watery diarrhea, vomiting, fever ▪ Adults: less severe symptoms DIAGNOSIS LAB RESULTS Blood tests ▪ ↑ blood urea nitrogen (BUN) ▪ Hyperchloremic acidosis ▪ ↓ serum calcium Stool analysis ▪ Immune based assays ▫ Enzyme linked immunosorbent assay (ELISA), latex agglutination tests (best diagnostic tests); PCR, culture 500 OSMOSIS.ORG TREATMENT OTHER INTERVENTIONS ▪ Most cases are self-limited, do not require pharmacotherapy ▫ Antidiarrheal medications not recommended (they delay elimination of infectious agent from intestines) ▪ ↑ ﬂuid intake; oral rehydration solutions ▪ Good nutrition ▪ If infection is severe ▫ Hospitalization for IV ﬂuids Prevention ▪ Live attenuated vaccine is indicated routinely for all infants, except for those with history of intussusception/severe combined immunodeﬁciency (SCID)
Osmosis High-Yield Notes
This Osmosis High-Yield Note provides an overview of Reoviruses essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Reoviruses by visiting the associated Learn Page.