Viral Hepatitis Flashcards
What is a viral tegument?
A.K.A. viral matrix - cluster if proteins that line space between envelope and nucleocapsid in herpesviruses
Explain Viral structure
2 components make nucleocapsid
-Nucleic acid genome (ss/ds RNA/DNA)
-protein capsid - composed of capsomeres
~Some viruses contain a lipid envelope
Aetiology of viral hepatitis
Mediated by viral pathogens e.g. Hepatitis A & E (faecal-oral transmission) & Hepatitis B,C, &D (bloodborne)
Hepatitis A Virus
~FAMILY - Picornavirus
~GENUS - Hepatovirus
~GENOME - RNA
~ENVELOPE - Nonenveloped
Hepatitis B Virus
~FAMILY - Hepadnaviridae
~GENUS - Orthohepadnavirus
~GENOME - DNA
~ENVELOPE - Lipid envelope
Hepatitis C Virus
~FAMILY - Flaviviridae
~GENUS - Hepacivrus
~GENOME - RNA
~ENVELOPE - Lipid envelope
Hepatitis D Virus
~FAMILY - kolmioviridae
~GENUS - deltavirus
~GENOME - RNA
~ENVELOPE - Lipid envelope
Hepatitis E Virus
~FAMILY -Hepeviridae
~GENUS - Orthohepevirus
~GENOME - RNA
~ENVELOPE - Noneneveloped
Spread of HepA & HepE
Contaminated food, human waste in drinking water, poor personal hygiene, poor sanitation, intimate contact
Hepatitis A
~Nonenveloped ssRNA
~25% Hepatitis in developed world - 3.8/100,000
~Very contagious - incubation period (especially later1/2)
~Humans are the only natural reservoirs
~Acute hepatitis - severe among immunocompromised - acute liver failure
~Vaccine - 2 shots within 6 months
Hepatitis E
~E = enteric
~Enveloped ssRNA
~1/8 cases - more in Asia & Africa
~zoonosis - porcine & rodent
~Acute hepatitis - low DR - severe among immunocompromised - les severe than B & C
~Vaccine
HepA & HepE signs & symptoms
~EARLY - fever, joint pain, arthritis, rash, oedema
~MID (PRE-ICTERIC) - fatigue & muscle pain (anaemia), cold symptoms, fever, abdo pain, anorexia, nausea, dark urine & light stool (juandice)
~LATE (ICTERIC) - skin lesions (jaundice then causes pruritus & scratching)
HepA & HepE pathogenesis
Acute hepatitis
~15% fulminant hepatitis (immunocompromised) - hepatocyte necrosis - functions impaired
HepA & HepE diagnosis
~Biochemistry - LFT (increase in AST, ALT, & GGT) - Later stage: hypoalbunaemia & hyperbilirubinaemia
~Haematology - FBC & blood film - thromobocytopenia, haemolytic anaemia, iron defficient anaemia (low ferritin), long clotting times
~Microbiology - serology - IgM detected whem symtopns begin - 6 months - IgG afterwards (immune memory/vaccine)
Hepatitis B
~ enveloped icosahedral capsid dsDNA
~ Bloodborne - IV drugs, unprotected sex, contaminated medical/tattoo/piercing instruments
~Vertical transmission (woman-neonate)
~Vaccine
