Hepatitis refers to inflammation or injury of the liver. It can occur due to toxins, alcohol, drugs, autoimmune conditions, or infections. The most common cause worldwide is viral hepatitis — mainly Hepatitis A, B, C, D, E and the newer Hepatitis G virus. These viruses damage liver cells and may cause mild illness or lead to chronic liver failure.
In India and other Asian countries, the most common types are Hepatitis A, B and C. Some types spread through contaminated food and water, while others spread through infected blood or sexual contact.
Types of Viral Hepatitis
Viral hepatitis is mainly caused by six viruses: HAV, HBV, HCV, HDV, HEV and HGV. They differ in their mode of transmission, disease severity and long-term complications.
General Etiology
- Use of infected needles and syringes
- Transfusion of infected blood or blood products
- Intravenous drug use
- Unprotected sex with infected partner
- Contaminated food or water (HAV, HEV)
Hepatitis A
Hepatitis A spreads through contaminated food, water and poor hygiene. Eating raw shellfish from polluted water is a major source.
Pathophysiology
HAV enters through the mouth, reaches the intestine, travels to the liver and infects hepatocytes. It causes inflammation but does not lead to chronic hepatitis. Most patients recover completely.
Symptoms
- Fever
- Nausea, vomiting
- Jaundice
- Dark urine
- Loss of appetite
Treatment
No specific antiviral treatment. Supportive care is enough. Patients usually recover fully.
Hepatitis B
A serious liver infection caused by HBV. It spreads through blood, unprotected sex, infected needles, and from mother to child. Hepatitis B may be acute or chronic. Chronic HBV increases the risk of liver cirrhosis and liver cancer.
Pathophysiology
HBV is a DNA virus that replicates inside liver cells. The immune system tries to clear infected hepatocytes, leading to liver inflammation and injury.
Symptoms
- Fatigue and fever
- Jaundice
- Loss of appetite
- Abdominal pain
Infants and children rarely show symptoms but often develop chronic infection.
Treatment
- Acute HBV: usually no specific treatment
- Chronic HBV: antivirals like lamivudine, adefovir, entecavir, peg-interferon
- Liver transplant may be required in severe liver damage
Prevention
Hepatitis B vaccine is the best protection for infants, children and adults at risk.
Hepatitis C
Caused by HCV. It spreads mainly through infected blood — especially unsafe injections and transfusions. Hepatitis C often becomes chronic and is a major cause of liver cirrhosis and liver cancer.
Pathophysiology
HCV primarily infects liver cells and sometimes B lymphocytes. Chronic infection causes slow liver inflammation and scarring.
Symptoms
Most patients are asymptomatic for years.
- Fatigue
- Weight loss
- Joint and muscle pain
- Low-grade fever
- In chronic cases: jaundice, ascites, bleeding, confusion
Treatment
HCV is now curable with direct-acting antiviral (DAA) drugs:
- Sofosbuvir + Ledipasvir
- Sofosbuvir + Simeprevir
- Combination with ribavirin or peg-interferon in some cases
No vaccine exists for hepatitis C.
Hepatitis D
Hepatitis D (HDV) requires the Hepatitis B virus to survive. It infects only people who already have HBV.
Types of Infection
- Co-infection: HBV + HDV together
- Superinfection: HDV infects a person already having chronic HBV
Superinfection is more dangerous and progresses faster to cirrhosis.
Symptoms
Similar to hepatitis B but often more severe.
Treatment
Peg-interferon is used, but complete cure is difficult. Preventing HBV infection also prevents HDV.
Hepatitis E
Spread through contaminated water. Common in areas with poor sanitation. Usually causes acute illness and does not become chronic.
Symptoms
- Jaundice
- Abdominal pain
- Dark urine
- Joint pain
- Neurological symptoms in rare cases
Treatment
Usually supportive. Ribavirin or interferon may be used in severe or chronic cases (rare).
Prevention
- Clean drinking water
- Good sanitation
- Avoiding uncooked food in endemic areas
Hepatitis G
Also known as GB virus C. It is an RNA virus similar to hepatitis C. It is found in human blood but does not cause liver disease. It may exist along with HIV, HBV or HCV but usually has no symptoms.
Common Symptoms Across All Hepatitis Types
- Nausea and vomiting
- Loss of appetite
- Weakness
- Fever
- Dark urine
- Pale stool
- Jaundice
- Abdominal pain
Diagnosis
Diagnosis includes blood tests, liver function tests and specific viral markers.
Important Investigations
- ALT, AST, ALP, GGT — liver enzymes
- HAV IgM, HBV surface antigen, HBV core IgM
- HCV antibody followed by HCV RNA
- HDV antibody and HDV RNA
- HEV IgM
- Liver biopsy in chronic hepatitis
Prevention of Viral Hepatitis
- Safe drinking water and sanitation (HAV, HEV)
- Using sterile needles and syringes
- Safe sex practices
- Screening blood before transfusion
- Vaccination for hepatitis A and B
- Avoid sharing razors, toothbrushes or nail cutters
Detailed Notes:
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