Viral Hepatitis Flashcards

Flashcards about Viral Hepatitis

Hepatitis

Inflammation of the liver due to infectious and non-infectious causes.

Symptoms of Hepatitis

Fever, right upper abdominal pain, nausea, vomiting, pale faeces, dark urine, and jaundice.

Jaundice

A reduction of bile excretion causing pale faeces, dark urine, and a yellow discoloration of the skin and eyes.

Biochemical Evidence of Hepatocyte Dysfunction

Lymphocytic inflammatory infiltrate and raised liver enzyme levels in blood.

Cirrhosis

Scarring and nodular regeneration of the liver.

Hepatitis Viruses

Tendency to cause hepatitis as the dominant component of the clinical illness.

Hepatitis A

ssRNA Picornavirus transmitted via the faecal-oral route.

Hepatitis A Transmission

Shed from faeces in large amounts, especially early in infection.

Hepatitis A Stability

Stable for 1 week at room temperature and for 30 days at 25°C in dried faeces.

Hepatitis A Replication

Replicates initially in the intestine and then in the liver.

Hepatitis A Diagnosis

IgM is detectable in blood from onset of illness and persists up to 6 months.

Routes of Hepatitis A Transmission

Close contact, sexual transmission, contaminated food or water, blood transfusions.

Who Gets Hepatitis A (Developed Countries)

Household contacts of cases, day care workers, travellers, men who have sex with men.

Who Gets Hepatitis A (Developing Countries)

Children, general population, household contacts.

Hepatitis A Prevention

Improved hygiene and sanitation, good personal hygiene, avoid exposure, immunization.

Hepatitis A Vaccine

Formalin inactivated hepatitis A virus given in two doses > 6 months apart.

Hepatitis E

ss(+) RNA, nonenveloped virus transmitted via the faecal-oral route.

Hepatitis E Transmission

Contaminated water or food, commonest where sanitation is poor.

Hepatitis E Genotypes

GT 1&2 infect humans, GT 3, 4, and 7 found in humans and animals.

Hepatitis E Acquisition in Australia

Zoonotic infection from swine.

Hepatitis E Diagnosis

Antibody detection (IgM in blood) and virus detection in faeces by PCR.

Hepatitis B Virus

Double stranded DNA virus of the hepadnavirus family.

Transmission of Hepatitis B

Neonatal infection, sexual transmission, exposure to blood or other infectious body fluids.

HBsAg

Hepatitis B surface antigen; detected in blood of actively infected patients.

Hepatitis B e antigen (HBeAg)

Indicates high level growth; found in acute infection and in carriers with poorly controlled virus replication.

Hepatitis B surface antigen (HBsAg)

Persistence for > 6 months defines the carrier state.

Positive HBeAg

High level replication and high infectivity.

Negative HBeAg

Usually low level replication and low infectivity.

Reduction of Hepatitis B Exposure

Education, safe sex, IVDU, body substance precautions in the workplace.

Hepatitis B Vaccination

Recombinant vaccine produced in yeast cells express the surface antigen.

Hepatitis B Treatment Candidates

High replication carriers and/or have high HBV DNA levels and/or have evidence of moderate/severe liver damage

Hepatitis C

Single stranded RNA virus; Member of the Flaviviridae.

Impact of Hepatitis C

Leading cause of end stage liver disease, hepatocellular carcinoma and liver related deaths in the Western world.

Major Risk Factors for Hepatitis C

Current or past injecting drug use, blood transfusion prior to introduction of donor screening.

Hepatitis C and Cancer

Hepatitis C is the commonest cause of liver cancer worldwide