Rotavirus and Hepatitis Viruses Flashcards
nucleic acid of rotavirus
dsRNA, encapsulated
nucleic acid of norovirus
naked, positive sense ssRNA
nucleic acid of adenovirus
naked, DNA
VP1 protein, rotavirus
- transcriptase
VP3, rotavirus
- mRNA capping
VP4, rotavirus
- hemagglutinin, involved in attachment
VP7, rotavirus
- induces formation of neutralizing antibodies, leads to immunity
rotavirus capsid
- protects virus from stomach acid
- partial acid digestion cleaves VP4
- produces infectious sub-viral particle (ISVP)
ISVP, rotavirus
- penetrates cell
- dsRNA replicated
- VPs made
- lyse cell
NSP4, rotavirus
- promotes Ca influx into enterocytes
- secretion of water and loss of ions leads to watery diarrhea
transmission of rotavirus
- fecal oral
- survives well on fomites and hands
clinical disease of rotavirus
- major cause of gastroenteritis in infants
- vomiting, diarrhea, fever, dehydration
- no RBCs or WBCs
transmission of norovirus
- fecal oral
- cruise ships and infected food handlers
clinical disease of norovirus
- 24-48 hour incubation
- acute onset of diarrhea and N/V
- virus compromises intestinal brush border function and prevents absorption of water and nutrients
- NO blood
nucleic acid of YF
- positive sense, ssRNA, enveloped
vector for YF
- Aedes aegypti mosquito
pathogenesis of YF
- kupffer cells infected in 24 hours
- viremic phase: malaise, fever, chills, headache
- conjunctival infection and facial flushing
- jaundice, dark urine, pale stools, generalized itching
black vomiting with jaundince
YF
YF vaccine
- live attenuated
- safe and effective in HIV patients with CD4 cells > 200/ ul
- DO NOT give to pregnant women
nucleic acid of hep A
- heparna virus (hep A RNA)
- picronavirus- RNA, naked
NA of hep B
- hepadna virus (hepa DNA)
- DNA, enveloped
NA of hep C
- flavivirus
- RNA, enveloped
NA of hep D
- delta virus
- circular RNA, enveloped
NA of hep E
- hepevirus (hep E virus)
- RNA, naked
transmission of hep A and E
- fecal oral
- vowels in the bowels
transmission of hep B,C, and D
- contaminated blood
characteristics of hep A
- naked, icosahedral capsid
- positive sense, ssRNA
- transmitted via fecal oral
pathogenesis of hep A
- virus ingested, enters bloodstream via GI tract
- replicates in hepatocytes and Kupffer cells
- released into bile and then stool
- shed about 10 days before symptoms
symptoms of hep A
- prodrome: fatigue, nausea, loss of appetite, ab pain
- icteric phase: jaundice, dark urine appears first then pale stool, ab pain, pruritus, arthralgias, skin rash
hep A prevention
- avoid uncooked shellfish
- vaccine: killed vaccine for infants at 2 and adults along with the HBV vaccine
hep B characteristics
- small, enveloped DNA virus
- encodes a reverse transcriptase and replicates through an RNA intermediate
immunopathogenesis of acute HBV infection
- T cell response causes:
- degeneration of liver parenchyma
- cellular swelling and necrosis
- inflammatory cell infiltrate
- jaundice
immunopathogeneis of chronic HBV infection
- insufficient T-cell response causes mild symptoms
- HBV DNA integrates into hepatocyte DNA
neutralizing antibody (nAb)
- can block virus binding and infection
- made against HBsAg (vaccination)
- immune complexes can form between HBsAg and nAb leading to type III hypersensitivity reactions and vasculitis, arthralgia, rash, glomerulonephritis
transmission of HBV
- contaminated blood
- sexual contact
- birth
- needlestick injuries
symptoms of acute HBV infection
- preicteric: fever, malaise, anorexia, nausea, vomiting, ab discomfort, chills
- icteric: liver damage (jaundice, dark urine, pale stools), fulminant hepatitis
symptoms of chronic HBV infection
- scarring, cirrhosis, liver failure or PHC
HBsAg
- indicates infection
- if present, actively replicating virus
- if present for more than 6 months, then chronic infection
HBsAb
- confers immunity
- if present, indicates resolution or immunization
HBeAg
- correlates with active viral replication
- present during acute disease and active chronic disease
- indicates extremely infective
HBeAb
- present in chronic disease
- indicator of actively making virus
HBcAb
- first Ab to appear
- presence indicates recent infection
- both IgM and IgG Ab present
treatment of hep B
- hep B immune globulin for recent exposure (within 1 week of exposure)
- HIV RT inhibitors or nucleoside analogs for 1 year
HBV vaccine
- contains HBsAg S gene
- series of 3 injections
characteristics of hep C
- positive sense, RNA, enveloped
- chronic, cirrhosis, cancer
- flaviviridae family
transmission of hep C
- blood and body secretions
- IV drug abusers prominent
replication of hep C
- coats itself with LDL or VLDL and uses these for uptake into hepatocytes
- virion buds into and remains in ER
HCV pathogenesis
- HCV proteins inhibit apoptosis and INF-a by binding to TNF-R and protein kinase R
- CMI responsible for producing tissue damage
HCV symptoms
- 3 types of disease: acute, severe rapid progression and chronic persistent infection
diagnosis of HCV
- ELISA for anti-HCV antibody
treatment for HCV
- recombinant INF-a +- ribavarin
characteristics of hep D
- HBsAg is essential for packaging the virus
- coinfection occurs with hep B
- superinfection can occur
- very small, ssRNA
coinfection
- Hep B and D transmitted together
- takes 2-3 months to make surface antigen
superinfection
- have hep B and then get hep D
- acute liver failure in days to weeks
replication of hep D
- HBsAg binds to hepatocytes and the virus enters
- original genome forms a ribozyme
- promotes association of genome with HBsAg to form virion
symptoms of hep D
- fulminant hepatitis common: severe, alters brain function, extensive jaundice, massive hepatic necrosis
prevention of hep D
- immunization with HBV vaccine protects against HDV
characteristics of hep E
- norovirus
- fecal oral transmission
- mostly in developing countries
- serious in pregnant women - 20% mortality
major glycoprotein component of HBV virion
- S
essential glycoprotein component of HBV virion assembly
- L
replication of hep B
- HBV attaches to hepatocytes mediated by HBsAg
- DNA genome delivered to nucleus
- copies genome in the cytoplasm