Public health and viral hepatitis Flashcards
What is the management of chronic HCV infection?
Rx dependent on genotype (1-6)
IFN treatments no longer recommended
Aim to have undetectable HCV titre of RNA at 6 months post-Rx
Current Rx: proteosomal inhibitors combo ± ribavirin
What are the side effects with ribavirin?
haemolytic anaemia,
cough.
Women should not become pregnant within 6 months of stopping ribavirin as it is teratogenic
What are the side effects of interferon-alpha based Rx?
flu-like symptoms, depression, fatigue, leukopenia, thrombocytopenia
How is chronic hepatitis C defined?
persistence of HCV RNA in blood for 6 months after exposure
What are the potential complications of chronic HCV infection?
rheumatological problems: arthralgia, arthritis
eye problems: Sjogren’s syndrome
cirrhosis (5-20% of those with chronic disease)
hepatocellular cancer
cryoglobulinaemia: typically type II (mixed monoclonal and polyclonal)
porphyria cutanea tarda (PCT): it is increasingly recognised that PCT may develop in patients with hepatitis C, especially if there are other factors such as alcohol abuse
membranoproliferative glomerulonephritis
What are the main stages in viral hepatitis Sx presentation/infection?
Stage 1: NO Sx
infected, viral replication
Stage 2: NON-SPECIFIC Sx
- anorexia, nausea, vomiting, arthralgia, malaise, fatigue, itchy skin
- difficult to Dx based on Sx
Stage 3: DARK URINE, PALE STOOLS
- GI Sx and malaise
- jaundice
- may also develop RUQ pain and hepatomegaly
Stage 4: Sx RESOLVE
- LFTs return to normal
- jaundice disappears
How do some people not realise they have chronic hepatitis?
the initial (acute) infection may have been insidious and likely asymptomatic Would not be able to tell unless there were Sx
What is a clinical diagnosis of viral hepatitis based on?
- history (jaundice and other associated Sx)
- exposure (risk groups)
- grossly elevated ALT/AST, moderately elevated GGT and ALP
- vaccination history: (HAV and HBV absent)
- Absence of other Sx indicating neoplasia or other causes
What is a laboratory Dx of viral hepatitis based on?
Serology: detection of Ab and/or Ag
- usually by enzyme linked assays
- detection of RNA or DNA by PCR
What are alternative older terms for HAV and HBV?
HAV: infectious jaundice
HBV: serum hepatitis (as spread via blood products)
What are the main points about HAV?
most infectious before Sx develop, but many are asymptomatic and mild. More severe in those with chronic liver disease.
Sx more common in adults than in children
Very rarely fatal
No chronic infection, individuals are immune following infection
No Rx, vaccine available
Faecal oral transmission
What is the relationship between Sx and Ig serotype for most viral infections?
by the time Sx appear, there will be detectable IgM titres
exception: measles
What are the methods to prevent HAV?
PRE-EXPOSURE
immunisation with purified inactivated whole virus vaccine
at risk groups in UK and travellers are encouraged to get vaccine
POST-EXPOSURE
public health will contact at risk individuals in outbreak
Vaccines and/or immunoglobulins are given
What are the main points about HBV?
spread by bodily fluids e.g. blood Vertical transmission is an important problem
many asymptomatic infections, but can cause fulminant infection leading to death
chronic infection leads to cirrhosis and HCC risk, but can be treated to keep viral load low
Vaccine available
Large number of people worldwide are infected with HBV
Highest susceptibility for chronic HBV with acute infection at birth (90%)
What are the different types of HepB Ag?
HBsAg: surface Ag, produced in mass so one of the first Ag that the immune system will generate Ab against
HBcAg: nucleocapsid core Ag, associated with having had an infection either chronic or resolved
HBeAg: only present in some strains of HBV, usually indicates acute or chronic active disease
HBeAg is a splice variant of HBcAg
