Viral Hepatitis Flashcards
What is hepatitis?
Inflammation of the liver
Viral hepatitis = inflammation of the liver as a result of direct viral infection
Define acute hepatitis
Hepatitis within last 6 months
Define chronic hepatitis
Any hepatitis lasting for longer than 6 months
Possible symptoms of acute hepatitis
General malaise
Myalgia
GI upset
Abdominal pain (particularly in the right upper quadrant)
With/without cholestatic jaundice (pale stools, dark urine)
Tender hepatomegaly
Infective causes of acute hepatitis
Viral - Hepatitis A and E
-Herpes viruses e.g. EBV (Epstein Barr Virus), CMV (Cytomegalovirus), VZV (Varicella Zoster Virus)
Non-viral - Leptospirosis
- Toxoplasmosis
- Coxiella (Q fever)
*Non-Infective causes of acute hepatitis
Alcohol Drugs Toxins/poisoning Pregnancy Autoimmune Hereditary metabolic
Signs of Chronic liver disease
Clubbing
Palmar erythema
Dupuytren’s contracture (one or more fingers bending into palm of hand)
Spider naevi
Infective causes of chronic liver disease
Hepatitis B (+/- D) Hepatitis C
Non-infective causes of chronic liver disease
Alcohol
Drugs
Autoimmune
Hereditary metabolic
Describe genetic appearance of Hepatitis A
Small, undeveloped RNA virus
Clinical presentation of Hepatitis A
Incubation period of 28 days.
Nausea, anorexia and distaste for cigarettes.
After 2 weeks, jaundice, with dark urine and pale stool.
Sometimes hepatomegaly
Pathophysiology of Hepatitis A
Picornavirus
Viral replication occurs in infected hepatocytes
>Destruction of hepatocytes due to immune response and viral life cycle
>Hepatitis
>Hepatic symptoms
Virus particles shed through biliary tree into faeces. Most infectious just before jaundice
How is Hepatitis A spread?
Faecal-oral route
Associated with shellfish
Epidemiology of Hepatitis A
Most common viral hepatitis in the UK
Diagnosis of Hepatitis A
Blood = ALT rises (Alanine transaminase) IgM = Antibody to HAV
Treatment of Hepatitis A
Prevention by vaccine
Treatment includes treating symptoms and avoiding alcohol
Complications of Hep A
Cholestatic hepatitis
Rarely, liver failure and death
Clinical presentation of Hep B (also D)
Flu like symptoms
Fever
Jaundice in 10% of younger and 50% of adults
Pathophysiology of ACUTE Hep B
Infected Hepatocyte
>Strong cellular immune response
>usually clearance of infection
>Still presents elevated liver enzymes and antibodies to HBV antigen
Possible to not be cleared -> fulminant liver failure (1% chance)
Pathophysiology of CHRONIC Hep B
HBsAg (Hep B surface Antigen) levels persist for 6 months.
(Due to the virulence of the strain or the immunocompetence and age of the patient.)
In cases of vertical transmission there is an immune tolerance of HBV antigens that precedes a stage of immune clearance after 2-3 decades.
This is when hepatitis and cirrhosis present.
Spread of Hep B
Parental route
Infected blood or bodily fluids
Mostly intercourse or vertical transmission
What is the most common viral hepatitis in the UK
Hepatitis A
What is most common cause of hepatitis worldwide
Infection by Hep B
Diagnosis of Hep B (also D)
Blood - ALT rises
HBaAg, HBcAb, HBsAb, IgM HBcAb (antibodies)
HBsAg is present 1-6 months after exposure. Presence for me than 6 months implies carrier status
Treatment of Hep B
Avoid unprotected sex and alcohol
Treatment - treat symptoms
Fulminant hepatitis - antivirals
Complications of Hep B
Fulminant Hepatic failure (rare)
Chronic HBV infection and Cirrhosis can lead to hepatocellular carcinoma
Clinical presentation of Hep C
Incubation period of 6-9 weeks
Often asymptomatic in acute infection
Chronic infection may present with malaise, weakness and anorexia
What is Hepatitis B virus (what kind of genetic material is it)
Enveloped dsDNA reverse transcription virus
What is Hepatitis C virus (what kind of genetic material is it)
Enveloped RNA virus
Pathophysiology of Hep C
Acute infection: can resolve spontaneously, or progress to chronic.
Chronic: sustained infection of hepatocytes -> damage to the cells -> cirrhosis and liver disease
Blood borne virus
How is Hep C spread
Blood borne
Mostly transmitted by poorly sterilised instruments/shared needles
Hep C Epidemiology
Six numbered genotypes of which:
1 makes up 50% of cases
2 and 3 make up 40% of cases
Diagnosis of Hep C
Liver enzymes show rise
Antibodies to HCV (or HCV RNA diagnoses acute infection)
(antibodies present within 4-6 wks)
Treatment of Hep C
Antivirals - weekly subcut (SC) pegylated interferon alpha-2a and daily oral Ribavirin
Information = advise on not sharing neddles
Complications of Hep C
Liver failure
If cirrhosis was found, could get hepatocellular carcinoma
Describe Hep E virus
RNA virus
similar to Hep A - acute only
How is Hep E spread and how is it prevented
Faeco-oral route
usually spread by contaminated water, rodents, dogs and pigs
Prevention by good sanitation and hygiene
True or False:
You can only get infected with Hep E once
True Once you’ve had Hep E then you cannot get infected again - 100% immunity
Treatment of Chronic Hepatitis B
SC Pegylated Interferon-Alpha 2a (immunodilatory treatment) - also for Hep D
Nucleos(t)ide analogues (inhibit viral replication) e.g. Oral Tenofovir
What is Hep D
Incomplete RNA virus enclosed in a shell of Hep B surface antigen (HBsAg)
Requires Hep B virus for assembly, allowing virus to replicate
Transmission of Hep D
Blood-borne
Epidemiology of Hep D
Common in Eastern Europe
Risk factors of Hep D
IV drug users
all same as HBV
Pathophysiology of Hep D
If acquired simultaneously with HBV (co-infection), causes increased severity of acute infection.
Co-infection:
Clinically indistinguishable from acute icteric (jaundice) HBV infection
Serum IgM anti-HDV confirms co-infection
Superinfection:
When someone with chronic HBV gets HDV
Results in secondary acute hep and increased rate of liver fibrosis progression
Hep C prevention
No vaccine available
Previous infection DOES NOT confer immunity - can be re-infected
Screen blood products
Precaution with handling bodily fluids
