Hepatitis

Definition of Hepatitis

• Breakdown of the term:

  • Prefix: Hepat - meaning "liver"

  • Suffix: -itis - meaning "inflammation"

• Definition: Hepatitis refers to liver inflammation.

Causes of Liver Inflammation

• Various causes of liver inflammation include:

  • Drugs or medications

  • Excessive use of alcohol

  • Most commonly: Viral infections

• Long-term complications from hepatitis include:

  • Cirrhosis

  • Liver cancer

  • Liver failure

Anatomy and Physiology of the Liver

Function of the Liver

• Acts as the body's gatekeeper

  • Filters and stores substances

  • Protects (immune function)

  • Breaks down substances

• Critical functions include:

  • Normal functioning is vital; dysfunction can lead to systemic failure

Location and Structure of the Liver

• Located in the right upper quadrant of the abdomen, beneath the diaphragm

• Structure: Two lobes, divided into eight segments called lobules

  • Lobules: Functional units containing hepatocytes (liver cells)

Blood Supply to the Liver

• Receives blood from two sources:

  • Hepatic Artery:

  • Delivers oxygen-rich blood from the heart (aorta)

  • Oxygen is crucial for cell function

  • Portal Vein:

  • Delivers nutrient-rich but oxygen-poor blood from the digestive system

  • Responsible for nutrient processing, detoxification

Functions of the Liver

• Filtration:

  • Removes toxins, provides protection

• Storage:

  • Stores glucose, vitamins, and nutrients

• Production of Proteins:

  • Clotting factors (importance of vitamin K)

• Ammonia Metabolism:

  • Converts ammonia (from protein breakdown) to urea for kidney excretion

  • High ammonia levels lead to confusion (impact on brain function)

• Bilirubin Management:

  • Breaks down red blood cells; bilirubin is produced

  • Bilirubin is excreted via stool; dysfunction leads to jaundice (yellowing of skin and eyes)

• Bile Production:

  • Aids in fat digestion; stored in the gallbladder

Overview of Viral Hepatitis Types

• Focus on comparing Hepatitis A, B, C, D, and E

  • Transmission routes

  • Acute vs Chronic infections

  • Diagnostic tests insights

  • Treatment and prevention measures

Hepatitis A

• Transmission:

  • Fecal-oral route (food, water contamination)

  • Poor hand hygiene post bathroom use can lead to transmission

• Infection Type:

  • Causes only acute infections

• Symptoms:

  • GI symptoms: Nausea, vomiting, stomach pain, loss of appetite

  • Jaundice, fever, fatigue, dark urine, clay-colored stool, joint pain

• Contagious Period:

  • 2 weeks before and 1-3 weeks after symptom onset

• Diagnostic Testing:

  • Detection of antibodies (IgM indicates active infection; IgG indicates past infection or vaccination)

  • Remember:

  • IgM = "virus is present"

  • IgG = "infection is gone/recovered"

• Treatment:

  • Supportive care, no specific medications; recovery is natural

• Prevention:

  • Vaccine available; part of childhood vaccination schedule

  • Hand hygiene critical

  • Post-exposure immune globulin available if administered within 2 weeks

Hepatitis B

• Transmission:

  • Spread through blood and body fluids (saliva, semen)

  • Major routes: sexual intercourse, IV drug use, vertical transmission (mother to child)

• Infection Type:

  • Causes both acute and chronic infections

  • Chronic infections can lead to serious liver issues (cirrhosis, liver cancer)

• Symptoms:

  • Typical hepatitis symptoms (as seen in Hepatitis A)

• Diagnostic Testing:

  • Positive hepatitis B surface antigen indicates an infectious (active) infection

  • Antibodies present indicate immunity (via vaccination or recovery)

• Treatment:

  • Acute: Supportive care

  • Chronic: Antivirals (e.g., PEG interferon alpha 2, subcutaneous injection)

• Prevention:

  • Vaccine series available (part of pediatric schedules)

  • At-risk populations (healthcare workers) encouraged to vaccinate

  • Post-exposure guidelines include administering hepatitis B immune globulin, preferably within 12-24 hours post-exposure