Chapter 27.docx

Chapter 27 JAUNDICE  Jaundice, a yellowish discoloration of body tissues, results from an alteration in normal bilirubin metabolism or flow of bile into the hepatic or biliary duct systems.  The three types of jaundice are hemolytic, hepatocellular, and obstructive. o Hemolytic (prehepatic) jaundice is due to an increased breakdown of red blood cells (RBCs), which produces an increased amount of unconjugated bilirubin in the blood. o Hepatocellular (hepatic) jaundice results from the liver’s altered ability to take up bilirubin from the blood or to conjugate or excrete it. o Obstructive (posthepatic) jaundice is due to decreased or obstructed flow of bile through the liver or biliary duct system. HEPATITIS  Hepatitis is an inflammation of the liver. Viral hepatitis is the most common cause of hepatitis. The types of viral hepatitis are A, B, C, D, E, and G.  Hepatitis A o HAV is an RNA virus that is transmitted through the fecal-oral route. o The mode of transmission of HAV is mainly transmitted by ingestion of food or liquid infected with the virus and rarely parenteral.  Hepatitis B o HBV is a DNA virus that is transmitted perinatally by mothers infected with HBV; percutaneously (e.g., IV drug use); or horizontally by mucosal exposure to infectious blood, blood products, or other body fluids. o HBV is a complex structure with three distinct antigens: the surface antigen (HBsAg), the core antigen (HBcAg), and the e antigen (HBeAg). o Approximately 6% of those infected when older than age 5 develop chronic HBV.  Hepatitis C o HCV is an RNA virus that is primarily transmitted percutaneously. o The most common mode of HCV transmission is the sharing of contaminated needles and paraphernalia among IV drug users. o There are 6 genotypes and more than 50 subtypes of HCV.  Hepatitis D, E, G o Hepatitis D virus (HDV) is an RNA virus that cannot survive on its own. It requires HBV to replicate. o Hepatitis E virus (HEV) is an RNA virus that is transmitted by the fecal-oral route. o Hepatitis G virus (HGV) is a sexually transmitted virus. HGV c