viral hepatitis Flashcards
what are non viral causes of hepatitis
toxoplasmosis (a parasite) drugs- paracetamol alcohol poisons other- pregnancy, circulatory insufficiency
what are the stages of viral replication
- Adsorption
- Penetration
- Uncoating
- Replication of nucleic acid
- Maturation / assembly
- Release
what are the features of Hep A
• Picornaviridae family • Single-stranded RNA virus • Non-enveloped virus (naked) • Only 1 serotype usually mild and acute
how is hep A spread
faecal oral poor hand hygeine contaminated food and water shellfish (improperly cooked) not common in the uk
what are the stages of HAV infection
• Incubation period of 2-4 weeks (prodromal
phase)
• Virus excreted in faeces for 1-2 weeks before
symptoms
• Translocation from GI tract to blood
• Infection of liver cells
• Passage to biliary tract and back to GI tract
• Excretion in faeces
what are the features of HAV
• Fever, anorexia flu like symptoms, joint pain • Nausea, vomiting • Jaundice • Dark urine, pale stools • Liver moderately enlarged • Spleen palpable in 10% patients • No chronic carriage • Diagnosed by presence of anti-HAV IgM • Prognosis excellent (mortality 0.1%) in young adults • Death if fulminant hepatic necrosis occurs
what is the treatment for HAV
- No specific treatment
- Maintain comfort and nutritional balance
- Fluid and electrolyte replacement
How is HAV prevented
- Vaccine
* Good hygiene
what are the viral features of HBV
- Hepadnaviridae
- Double-stranded DNA virus
- Enveloped virus
how is HBV transmitted
• Sexual intercourse
• Intra-uterine, peri- and post-natal infection
• Blood or blood products
• Contaminated needles and equipment used
by intravenous drug users
• In association with tattooing, body piercing
and acupuncture
• Contaminated haemodialysis equipment
what are the HBV stages of infection
- Incubation period of 2-4 months
- 50% patients develop chronic active hepatitis
- 20% of these proceed to cirrhosis
- 1-4% of these risk developing liver cancer
what does icteric mean
jaundiced
what are the clinical features of preicteric HBV
can be severe, acute or sometimes chronic worse with hep d Malaise anorexia nausea pain in URQ emesis flu like symptoms
how is HBV treated
Pegylated interferon
Nucleoside analogues such as oral lamivudine
may not be treated
how is HBV prevented
- Vaccination: 3 injections over 6 months
- HBV immunoglobulin
- Blood screening
- Needle exchange programmes
- Sexual health education
what are the viral features of hep c
Flaviviridae
• Single-stranded RNA
• Enveloped virus
what are the symptoms of hep c
often subclinical usually chronic may be assymptomatic flu-like symptoms, such as muscle aches and a fever feeling tired all the time loss of appetite abdominal pain feeling and being sick
may develop to cirrhosis or carcinoma
no vaccine
how is hep C spread
• Blood and blood products • Blood contaminated needles • Tattooing, body piercing, acupuncture • Haemodialysis mother to baby
what are the stages of hep c infection
virus replicates in hepatocytes
incubation period of several months
how can HCV be tested
blood test based on NAAT
how is HCV treated
ribavirin and pegylated interferon
what are the viral features of hep D
small circular single stranded RNA
defective
what are the features of hep D
•Found as co-infection with HBV
•HBV serves as helper virus for infectious HDV production
•Transmitted percutaneously, sexually, from infected blood
•Chronic HBV carriers are at risk for infection with HDV.
•No specific treatment is available
chronic infection
what are the viral features of hep E
- Caliciviridae
- Single-stranded RNA
- Non-enveloped virus
how is hep E transmitted
- Waterborne disease
- Peak incidence in young adults
- Incubation period 3-8 weeks
what are the symptoms of HEP
•Usually self-limiting
•Can be life-threatening in pregnant woman
•Signs and symptoms are similar to other acute forms of hepatitis
acute and not usually a problem unless pregnant
what are the other causes of viral hepatitis
- Epstein-Barr virus
- Cytomegalovirus
- Yellow fever virus
- Adenoviruses
- Bunyaviruses
- Flaviviruses
is hepatitis A acute or chronic
acute
what does picorniviridae cause
Hep A
what does hepadnaevirus cause
hep B
what does flaviviridae cause
hep c
what does herpeviridae/ caliciviridae cause
hep e
what does deltavirus cause
hep d
what is the only virus that is double stranded
hep B
what vaccines are available
hep A and B
what type of hepatitis does hep B cause
usually acute, may be chronic
may lead to cirrhosis or liver cancer
is hep c acute or chronic
chronic- 70%
usually asymptomatic for many years
eventually cirrhosis if untreated
which two infections are linked
D and B
D is chronic with B
what is the severity of hep E
usually acute
unless pregnant- may be fulminant
or immunocompromised - may be chronic
other wise similar to hep A
where is hep a most common
africa
south america
indian subcontinent
where is hep B most common
canada
africa
indian subcontinent
how do you tell that HBV has become chronic
presence of HBsAg and absence of antibodies
which hepatitis is waterborne
hep e
