8 Hepatitis C Flashcards
Hepatitis E. virus RNA family
RNA virus – herpesvirus family
hep E spread
faecal-oral spread
is hep E a chronic infection
if immunocompromised it is chronic
effect of hep E on pregnancy
higher mortality than HAV – especially in pregnancy
what is hep E associated with
usually associated with travel abroad, but endogenous infection increasingly recognised
which animal transmits hep E
zoonosis – genotype 3 virus found in pigs
hep C family
flavivirus
hep C RNA
+ve ss linear
what is the hep C capsid
icosaedric capsid
Quasispecies
swarm of closely related sequences within an individual
HCV genetic diversity: consequence - Diagnosis
may result in false negativity
HCV genetic diversity: consequences - pathogenicity
all genotypes equally dangerous
HCV genotypes: UK
Predominantly types 1 and 3
Some type 2
Anti-HCV positive
Evidence of infection at some time
problem with anti-HCV positive
Gives no indication as to when infection occurred
Gives no indication as to whether infection was cleared or is still present
Anti-HCV: Negative
No evidence of infection with HCV
problem with anti-HCV negative
BUT - be aware of possible false negatives
- if infection very recent (window period)
- if patient immunosuppressed at time of infection
Genome Detection
Look for the viral genome
what does genome detection require
Requires amplification e.g. Reverse Transcriptase Polymerase Chain Reaction
benefit of genome detection
Technically more exacting
con of genome detection
expensive
Interpretation RT/PCR result - Positive
- infectious
- risk of chronic liver disease
- requires liver biopsy
Interpretation RT/PCR results - negative
- not infectious
- not at risk of chronic liver disease
- no biopsy required
Hepatitis C virus routes of transmission
strongly linked to blood
Parenteral
- injecting drug use
- blood/blood products
- other needles
- failure of infection control e.g. outbreaks
Prevalence of anti-HCV amongst blood donors
HCV infection clearance %
20
HCV infection chronic infection %
80
Chronic HCV infection: Predictors of disease progression
Male sex
Older age at infection (aging liver doesn’t handle virus well)
Increase alcohol intake
Needlestick transmission of blood-borne hepatitis viruses
Infected patient to healthcare worker
or
Infected healthcare worker to patient
Protection of HCWs: HCV
- no vaccine, no passive immunisation
- treatment of acute infection = very high clearance rates
- encourage reporting of needlestick exposures
- monitor for evidence of HCV infection
- treat
