Hepatobiliary disorders Hepatitis Inflammation of the liver
Viral hepatitis (A, B, C, D, E, G) Most common cause Other possible
causes Drugs (alcohol) Chemicals Autoimmune liver disease Bacteria
(rarely) Hepatitis A virus (HAV) RNA virus Transmitted fecal-oral
route, parenteral (rarely) Frequently occurs in small outbreaks
Found in feces 2 or more weeks before the onset of symptoms and up
to 1 week after the onset of jaundice Present in blood briefly No
chronic carrier state Poor hygiene, improper handling of food,
crowded situations, and poor sanitary conditions are all factors
related to hepatitis A. Transmission occurs between family members,
institutionalized individuals, and children in day-care centers,
and as the result of common-source outbreaks.
Serologic Events in HAV Infection
Hepatitis A virus (HAV) Anti-HAV immune globulin M (IgM) Appears
in the serum as the stool becomes negative for the virus Detection
of IgM anti-HAV indicates acute hepatitis. Anti-HAV immune globulin
G (IgG) IgG anti-HAV: Indicator of past infection Presence of IgG
antibody provides lifelong immunity. Hepatitis B virus (HBV) DNA
virus Transmission of HBV Perinatally by mothers infected
Percutaneously (IV drug use) Horizontally by mucosal exposure to
infectious blood, blood products, or other body fluids Transmission
occurs when infected blood or other body fluids enter the body of a
person who is not immune to the virus. Sexually transmitted disease
Can live on a dry surface for 7 days Kissing/sharing food items may
spread the virus via saliva. More infectious than HIV Complex
structure with three antigens Surface antigen (HBsAg) Core antigen
(HBcAg) E antigen (HBeAg) Each antigencorresponding antibody may
develop in response to acute viral hepatitis B
Presence of hepatitis B surface antibodies Indicates immunity
from HBV vaccine Past HBV infection With chronic infection, liver
enzyme values may be normal or 15% to 25% of chronically infected
persons die from chronic liver disease. In North America,
approximately 0.5% of the population are HBV carriers; in parts of
Asia, the rate is approximately 8% to 10%. Hepatitis C virus (HCV)
RNA virus Transmitted percutaneously Risk factors IV drug use Most
common mode of transmission in United States and Canada Blood
transfusions Transmission
