Hepatitis A Flashcards
what is the definition of Hep A?
Hepatitis A virus (HAV) is an RNA virus. It is not associated with chronic liver disease. hepatovirus
what is the epidemiology of Hep A?
High prevalence - africa, parts of asia and latin america (poor hygiene)
Intermediate prevalence - southern and eastern europe, middle east
Low prevalence - western world
what is the aetiology of Hep A?
is a 27-nm, non-enveloped, icosahedral RNA virus
The virus is transmitted by close contact with an infected person or by contact with contaminated food or water products
what are the risk factors fro Hep A?
Endemic regions
Close personal contact
Known foodborne outbreak
what is the pathophysiology of Hep A?
After oral inoculation the virus is transported across the intestinal epithelium by a poorly understood transport mechanism. After travelling through the mesenteric veins to the liver, the virus enters hepatocytes, where replication of hepatitis A virus (HAV) occurs exclusively within the cytoplasm via RNA-dependent polymerase. Exact mechanism of injury is not proven, but there is evidence suggesting the role of a cell-mediated immune response, as shown to be mediated by HLA-restricted, HAV-specific CD8+ T lymphocytes, and natural killer cells
what are the key presentations of Hep A?
Presence of risk factors Fever Malaise Nausea and vomiting Jaundice Hepatomegaly RUQ pain Clay-coloured stool
what are the signs of Hep A?
Risk factors
Jaundice
Heptomegaly
what are the symptoms of Hep A?
Fever Malaise Nausea Fatigue Headache Dark urine Clay-coloured stool Pruritus Pain in upper right quadrant
what are the first line and gold standard investigations for Hep A?
Serum transferase - elevated
Serum bilirubin - elevated
Blood urea - elevated in fulminant hepatitis
Serum creatinine - elevated in fulminant
Prothrombin time - prolonged
IgM anti-hep A virus - positive
what are the differential diagnoses for Hep A?
Acute hep b, hep e, acute hep c, EBV
how is Hep A managed?
Hep A vaccine
Supportive care
Liver transplant
how is Hep A monitored?
Patents are followed up with weekly measurements of serum alanine aminotransferase, aspartate aminotransferase, and gamma-GT until confirmation of resolution of transaminitis
what are the complications of Hep A?
Acalculous cholecystitis, pancreatitis, aplastic anaemia
what is the prognosis of Hep A?
Approximately 85% of individuals infected with hepatitis A virus (HAV) have full clinical and biochemical recovery within a 3-month period with nearly all individuals recovering within 6 months
