Hepatitis
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Transcript of Hepatitis
Hepatitis
Dr. Meg-angela Christi M. Amores
Hepatitis
• Inflammation of the liver• Acute Viral Hepatitis• Toxic and Drug-induced Hepatitis• Chronic Hepatitis
Acute Viral Hepatitis
• Almost all cases of acute viral hepatitis are caused by one of five viral agents:– hepatitis A virus (HAV) – hepatitis B virus (HBV)– hepatitis C virus (HCV)– HBV-associated delta agent or hepatitis D virus
(HDV)– hepatitis E virus (HEV)
Hepatitis A
• Non-enveloped RNA virus• in the hepatovirus genus of the picornavirus
family • Inactivation of viral activity can be achieved by
boiling for 1 min, by contact with formaldehyde and chlorine, or by ultraviolet irradiation
Hepatitis A
• incubation period of ~4 weeks• replication is limited to the liver• viral shedding in feces, viremia, and infectivity
diminish rapidly once jaundice becomes apparent
Hepatitis A
• diagnosis of hepatitis A is made during acute illness by demonstrating anti-HAV of the IgM class
• After acute illness, anti-HAV of the IgG class remains detectable indefinitely
• patients with serum anti-HAV are immune to reinfection
Hepatitis A
Hepatitis A
• transmitted almost exclusively by the fecal-oral route
• Person-to-person spread of HAV is enhanced by poor personal hygiene and overcrowding
• contaminated food, water, milk, frozen raspberries and strawberries, green onions and shellfish
• Declining incidence in developed countries
Hepatitis B
• DNA virus• hepadnaviruses (hepatotropic DNA viruses)• Mode of transmission: – Percutaneous inoculation – intimate (especially sexual) contact and perinatal
transmission– Oral ingestion - potential but inefficient route of
exposure
Hepatitis B
Hepatitis C
• Linear, single stranded RNA Virus• genus Hepacivirus in the family Flaviviridae• Cell-mediated immune responses and
elaboration by T cells of antiviral cytokines contribute to the containment of infection and pathogenesis of liver injury associated with hepatitis C
Hepatitis C
• Mode of transmission:– Percutaneous inoculation• Transfusions• other percutaneous routes, such as injection drug use• occupational exposure to blood
– studies have failed to identify sexual transmission – chances of sexual and perinatal transmission have
been estimated to be ~5%
Symptoms and Signs
• occurs after an incubation period that varies • incubation periods for:– hepatitis A range from 15–45 days– hepatitis B and D from 30–180 days – hepatitis C from 15–160 days – hepatitis E from 14–60 days
Symptoms and Signs
• Prodromal Phase • symptoms: systemic, variable– anorexia, nausea and vomiting, fatigue, malaise,
arthralgias, myalgias, headache, photophobia, pharyngitis, cough, and coryza may precede the onset of jaundice by 1–2 weeks
– low-grade fever between 38° and 39°Cmore often present in hepatitis A and E than in hepatitis B or C
– Dark urine and clay-colored stools 1-5 days before jaundice appears
Symptoms and signs
• clinical JAUNDICE phase• liver becomes enlarged and tender • right upper quadrant pain and discomfort
jaundice
• Yellow coloration of skin, sclera, palms• visible in the sclera or skin when the serum
bilirubin value is >43 mol/L (2.5 mg/dL)• Bilirubin levels >340 mol/L (20 mg/dL)
extending and persisting late into the course of viral hepatitis – severe disease
Symptoms and Signs
• Recovery phase– constitutional symptoms disappear– some liver enlargement and abnormalities in liver
biochemical tests are still evident
– Complete clinical and biochemical recovery is to be expected 1–2 months after all cases of hepatitis A and E and 3–4 months after the onset of jaundice in three-quarters of uncomplicated, self-limited cases of hepatitis B and C
Lab Features
• serum aminotransferases aspartate aminotransferase (AST) and ALT (previously designated SGOT and SGPT) – variable increase during the prodromal phase – does not correlate well with the degree of liver
cell damage– Peak levels at time of clinical jaundice
• High bilirubin levels• Serologic tests
Diagnosis
Treatment
• antiviral therapy – not recommended in all cases of Hep B – due to complete recovery
• acute hepatitis C, recovery is rare, progression to chronic hepatitis is the rule
• interferon monotherapy • 24-week course (beginning within 2–3 months after
onset) of the best regimen identified for the treatment of chronic hepatitis C
Treatment
• most cases of typical acute viral hepatitis, specific treatment generally is not necessary
• patients will feel better with restricted physical activity
• high-calorie diet is desirable• Intravenous feeding when necessary
Prevention
• Hep A:– gloves should be worn when the bedpans or fecal
material of patients• Hep B and C:– blood precautions, i.e., avoiding direct, ungloved
hand contact with blood and other body fluids
• hand washing• Vaccination: Hep A, Hep B
Prognosis
• all previously healthy patients with hepatitis A recover completely
• hepatitis B, 95–99% of previously healthy adults have a favorable course and recover completely
• advanced age and with serious underlying medical disorders may have a prolonged course • prolonged PT, low serum albumin level, hypoglycemia,
and very high serum bilirubin values suggest severe hepatocellular disease