5.5.1 Hepatitis

Introduction

Hepatitis is a medical condition characterized by inflammation of the liver. It is generally caused by viral infections, though it can also result from toxicity of drugs and certain other causes. Viral hepatitis is a major global health problem. There are five main types of viral hepatitis: Hepatitis A, B, C, D, and E. Each type has different modes of transmission, symptoms, treatment, and prevention.

Definition

Hepatitis: Hepatitis is generally characterized as inflammation of the liver including other symptoms. It is generally caused by viral infection or rarely due to toxicity of drugs and certain other causes.

In simple words: Hepatitis is the inflammation of the liver, usually caused by a viral infection.

Core Concept

• Hepatitis is characterized by inflammation of the liver.
• It is generally caused by viral infection.
• It can also be caused by toxicity of drugs and certain other causes.
• It may present in:
• Acute form (recent infection, relatively rapid onset)
• Chronic form (slowly progressing)
• The most common causes of viral hepatitis are:

Detailed Explanation

Overview of Viral Hepatitis

Hepatitis "A"

Definition: Hepatitis A (also called infectious hepatitis) is caused by HAV.

• HAV is transmitted by the faecal-oral route.
• It is usually spread through contaminated food or water.
• The symptoms include:
• Fever
• Loss of appetite
• Nausea
• Vomiting
• Jaundice (yellowing of skin and eyes)
• Dark urine
• Pale faeces
• There is no antiviral therapy available.
• Prevention:
• Active immunization with a vaccine containing inactivated HAV.
• Observation of proper hygiene.

Hepatitis "B"

Definition: Hepatitis B (also called serum hepatitis) is caused by HBV.

• HBV is transmitted by:
• Blood
• Sexual contact
• Prenatally from mother to newborn
• The symptoms are similar to hepatitis A.
• Treatment: Alpha interferon is effective against HBV.
• Prevention:
• Vaccine is highly effective in preventing hepatitis B.
• All blood transfusion should be screened.

Hepatitis "C"

Definition: Hepatitis C is caused by Hepatitis C virus.

• HCV is transmitted only via blood.
• The symptoms are just like hepatitis B.
• Treatment: A combination of alpha interferon and ribavirin is the treatment choice for chronic hepatitis C.
• Prevention:
• No vaccine is available.
• Blood transfusion should be screened as a preventive measure.

Hepatitis "D"

Definition: The only human disease known to be caused by a viroid is hepatitis D.

• The only human disease known to be caused by a viroid is hepatitis D.
• The hepatitis D viroid can only enter a human liver cell if it is enclosed in a capsid that contains a binding protein.
• It obtains this from the hepatitis B virus.
• The viroid then enters the blood stream and can be transmitted via blood or serum transfusions.
• The symptoms are as in hepatitis B but more severe.
• Treatment and Prevention: Same as HBV.

Hepatitis "E"

Definition: Hepatitis E is caused by HEV.

• HEV is transmitted by the faecal-oral route (like HAV).
• There is no antiviral treatment and vaccine.
• Prevention: Observation of proper hygiene.

Comparison of Hepatitis Types

Summary Table of Hepatitis Viruses

Intermediate Level

Hepatitis A in Detail

Hepatitis B in Detail

Hepatitis C in Detail

Hepatitis D in Detail

Hepatitis E in Detail

Comparison of Hepatitis Types

Important Points

• 1. Hepatitis is generally characterized as inflammation of the liver including other symptoms.
• 2. It is generally caused by viral infection or rarely due to toxicity of drugs and certain other causes.
• 3. It may present in acute (recent infection, relatively rapid onset) or chronic (slowly progressing) forms.
• 4. The most common causes of viral hepatitis are Hepatitis A, Hepatitis B, Hepatitis C, Hepatitis D, and Hepatitis E.
• 5. Hepatitis A:
• - Cause: HAV
• - Transmission: Faecal-oral route
• - Symptoms: Fever, loss of appetite, nausea, vomiting, jaundice, dark urine, pale faeces
• - Treatment: No antiviral therapy
• - Prevention: Active immunization with a vaccine containing inactivated HAV; observation of proper hygiene
• 6. Hepatitis B:
• - Cause: HBV
• - Transmission: Blood, sexual contact, prenatally from mother to newborn
• - Symptoms: Similar to hepatitis A
• - Treatment: Alpha interferon is effective against HBV
• - Prevention: Vaccine is highly effective in preventing hepatitis B; all blood transfusion should be screened
• 7. Hepatitis C:
• - Cause: HCV
• - Transmission: Only transmitted via blood
• - Symptoms: Symptoms are just like hepatitis B
• - Treatment: A combination of alpha interferon and ribavirin is the treatment choice for chronic hepatitis C
• - Prevention: No vaccine is available; blood transfusion should be screened as preventive measure
• 8. Hepatitis D:
• - Cause: HDV (viroid)
• - Transmission: Blood or serum transfusions
• - Symptoms: As in hepatitis B but more severe
• - Treatment and Prevention: Same as HBV
• 9. Hepatitis E:
• - Cause: HEV
• - Transmission: Faecal-oral route
• - Treatment and Prevention: There is no antiviral treatment and vaccine; observation of proper hygiene

Remember

• - Hepatitis = liver inflammation
• - Hepatitis A = HAV; faecal-oral; vaccine
• - Hepatitis B = HBV; blood, sexual, prenatal; vaccine
• - Hepatitis C = HCV; blood; no vaccine
• - Hepatitis D = HDV; blood; requires HBV
• - Hepatitis E = HEV; faecal-oral; hygiene
• - Symptoms = fever, jaundice, dark urine, pale faeces
• - Treatment = antiviral drugs, interferon
• - Prevention = vaccines, hygiene, screening

Common Mistakes

• 1. Confusing the different types of hepatitis – Each type has a different cause, transmission, and prevention.
• 2. Thinking hepatitis A and E are blood-borne – Hepatitis A and E are faecal-oral.
• 3. Thinking hepatitis B and C are food-borne – Hepatitis B and C are blood-borne.
• 4. Thinking hepatitis D is independent – Hepatitis D requires HBV for replication.
• 5. Forgetting the treatment for hepatitis C – Interferon + ribavirin.
• 6. Thinking all hepatitis viruses have DNA – Only hepatitis B has DNA; others have RNA.
• 7. Thinking there is a vaccine for hepatitis C – There is no vaccine for hepatitis C.
• 8. Forgetting the symptoms – Fever, jaundice, dark urine, pale faeces.
• 9. Thinking hepatitis E is rare – Hepatitis E is common in developing countries.
• 10. Confusing acute and chronic hepatitis – Acute = short-term; Chronic = long-term.
• 11. Thinking hepatitis D is caused by a virus – Hepatitis D is caused by a viroid.
• 12. Forgetting the prevention measures – Vaccines, hygiene, screening.

Quick Revision

• Hepatitis is generally characterized as inflammation of the liver including other symptoms.
• It is generally caused by viral infection or rarely due to toxicity of drugs and certain other causes.
• It may present in acute (recent infection, relatively rapid onset) or chronic (slowly progressing) forms.
• The most common causes of viral hepatitis are Hepatitis A, Hepatitis B, Hepatitis C, Hepatitis D, and Hepatitis E.
• Hepatitis A:
• Cause: HAV
• Transmission: Faecal-oral route
• Symptoms: Fever, loss of appetite, nausea, vomiting, jaundice, dark urine, pale faeces
• Treatment: No antiviral therapy
• Prevention: Active immunization with a vaccine containing inactivated HAV; observation of proper hygiene
• Hepatitis B:
• Cause: HBV
• Transmission: Blood, sexual contact, prenatally from mother to newborn
• Symptoms: Similar to hepatitis A
• Treatment: Alpha interferon is effective against HBV
• Prevention: Vaccine is highly effective in preventing hepatitis B; all blood transfusion should be screened
• Hepatitis C:
• Cause: HCV
• Transmission: Only transmitted via blood
• Symptoms: Symptoms are just like hepatitis B
• Treatment: A combination of alpha interferon and ribavirin is the treatment choice for chronic hepatitis C
• Prevention: No vaccine is available; blood transfusion should be screened as preventive measure
• Hepatitis D:
• Cause: HDV (viroid)
• Transmission: Blood or serum transfusions
• Symptoms: As in hepatitis B but more severe
• Treatment and Prevention: Same as HBV
• Hepatitis E:
• Cause: HEV
• Transmission: Faecal-oral route
• Treatment and Prevention: There is no antiviral treatment and vaccine; observation of proper hygiene

60-Second Revision

• Hepatitis = liver inflammation
• Hepatitis A = HAV; faecal-oral; vaccine
• Hepatitis B = HBV; blood, sexual, prenatal; vaccine
• Hepatitis C = HCV; blood; no vaccine
• Hepatitis D = HDV; blood; requires HBV
• Hepatitis E = HEV; faecal-oral; hygiene
• Symptoms = fever, jaundice, dark urine, pale faeces
• Treatment = antiviral drugs, interferon
• Prevention = vaccines, hygiene, screening
• Warning: Each type of hepatitis has a different cause, transmission, and prevention. Hepatitis A and E are faecal-oral. Hepatitis B and C are blood-borne. Hepatitis D requires HBV for replication. Only hepatitis B has DNA; others have RNA. There is no vaccine for hepatitis C. Hepatitis D is caused by a viroid. Make sure you can distinguish between the five types.