Hepatitis B

Hepatitis B is a liver infection caused by the hepatitis B virus (HBV). It is a highly contagious virus that primarily spreads through contact with infected blood, semen, or other body fluids. Unlike some other forms of hepatitis, Hepatitis B is not spread through food, water, or casual contact such as sharing eating utensils, breastfeeding, hugging, kissing, holding hands, coughing, or sneezing.

How Hepatitis B Is Spread
HBV can be transmitted through several routes, including:

• Unprotected sexual contact: With an infected partner.
• Needle sharing: Among individuals who inject drugs.
• Mother-to-child transmission: During childbirth, particularly in regions where HBV is common.
• Exposure to infected blood: Through needlestick injuries, medical procedures with unsterilized equipment, or sharing items like razors or toothbrushes contaminated with infected blood.
• Blood transfusions: In rare cases, particularly in settings with inadequate blood screening.

Acute vs. Chronic Hepatitis B
Hepatitis B infections can present in two forms:

1. Acute Hepatitis B
   • Acute infections occur within the first six months after exposure to HBV.
   • Most healthy adults and older children infected with HBV experience a short-term illness and are able to clear the virus from their bodies.
   • Symptoms may include fatigue, fever, nausea, vomiting, abdominal pain, dark urine, and jaundice (yellowing of the skin and eyes). In some cases, acute HBV infections are asymptomatic.
   • Recovery typically leads to lifelong immunity against HBV.
2. Chronic Hepatitis B
   • Chronic infections develop when the body is unable to clear the HBV, allowing it to persist in the liver.
   • Chronic HBV infections are more common in younger individuals, particularly infants and young children.
     • Infants: About 90% of infants infected at birth develop chronic HBV.
     • Young children: Around 30% of children infected before age 6 become chronically infected.
     • Older children and adults: Less than 5% of infections result in chronic hepatitis B.
   • Chronic HBV can lead to serious health complications, including cirrhosis (scarring of the liver), liver failure, or liver cancer.