Hepatitis Flashcards
Viral causes of Hepatitis
Hep A, B, D, C, E
Human herpes viruses (HSV, VZV, CMV, EBV)
Which viral hepatitis are the most common contributers to liver disease and why
B & C because they go chronic
Non viral causes of hepatitis
Spirochetes (leptospirosis, syphilis)
Mycobacteria (tb)
Bacteria e.g. bartonella
Parasites e.g. toxoplasma
Global burden/trends of hep
Going up
B especially going up as no cure
C now a cure - so starting to come down
Chronic Hep B: 296 million
Chronic Hep C: 60 million
Hep B Transmission
Blood borne
Mother to child
Household contact
Blood products
Iatrogenic
Occupational
Sexual
IVDU
Natural history of Hep B
In immunocompetent adults
Acute infection either leads to spontaneous resolution (95%) (risk of reactivation if immunosuppressed) or chronic HepB infection (5%).
25% Chronic hep B leads to cirrhosis. Then may lead to HCC or decompensated cirrhosis
Symptoms of decompensated cirrhosis
Jaundice
Ascites
Encephalopathy
Coagulopathy
Hypoalbuminaemia
Variceal bleeding
Hep B natural history in neonates and infants
10% spontaneous resolution
90% chronic HBV infection
Hep D
defective RNA virus
requires HBsAg presence to replicate
Transmission: blood borne - most common = blood products, iatrogenic or IVDU
Hep C transmission
Blood borne - blood & bodily fluids
mother to child
household contact
blood products
iatrogenic
occupational
MSM
injecting drug use
tattoos, piercings
Hep C Natural history in immunocompetent
30% spontaneous resolution
70% chronic –> cirrhosis & HCC
Hep E
Endemic in UK
Faeco-oral transmission
- contaminated food and water
- undercooked meat
chronic - rare
Hep A
Very low prev UK
Faeco-oral transmission
- contaminated food and water
- linked to poor access to WASH
- In high income countries: travel, MSM & IVDU
.35% fulminant hep
No chronic disease
Lifelong immunity post exposure
What is elimination of disease
reduction to 0 incidence in defined geographical location, continued intervention measures recquired
What is elimination of infection
Reduction to zero of incidence of infection caused by a specific agent in a defined geographical area as a result of deliberate efforts; continued measures to prevent re-establishment of transmission are required.
e.g. poliomyelitis
What is eradication
Permanent reduction to zero of worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed.
e.g. smallpox
What is extinction
doesn’t even exist in labs etc
Indicators of eradicability
- effective intervention available to interrupt transmission of agent
- practical diagnostic tools to determine levels of infection that can lead to transmission
- humans are essential for lifecycle: independent reservoir/environmental amplification makes v difficult to control
Measures to eradicate Hep B
- Universal childhood hep V vaccination
- PEP for neonates with positive mothers
- Screening of blood products
- Single use sterile medical equipment
- safe disposal of sharps & body waste
- needle syringe exchange
- opiate substitution therapy
- safe sex education & condoms
- vaccination of high risk
- screening & immunisation of susceptible contacts
- patient education
- treatment as prevention
potential measures to eradicate Hep C
No vaccine
- screening blood products
- sterile medical equipment
- universal precautions
- safe disposal
- needle exchange
- opiate therapy
- safe sex & condoms
- screening of contacts
- patient education
- DAA (treatment)
- treatment as prevention
5 core WHO strategy interventions for viral hep
- Vaccines (ABE)
- Prevention of mother to child transmission of HBV
- Injection, blood & surgical safety
- harm reduction for IVDU
- Treatment (B&C)
Barriers to hep B elimination
- immigrant population
- stigma
- low education levels
- low resources (expand)
- lack of political priority
Barriers to Hep C elimination
- difficult to engage at risk population (mostly IVDU)
- Conflicting priorities
- lack of awareness
- stigma
- cost of treatment
- lack of resources
- lack of political priority
