HBV is present in high concentration in the blood and bodily fluids of many hepatitis B virus carriers.
Transmission predominantly occurs through percutaneous or mucosal exposure to infected blood and various body fluids, including saliva, menstrual, vaginal, and seminal fluids
- sexual transmission
- particularly in unvaccinated men who have sex with men and heterosexual persons with multiple sex partners or contact with sex workers.
- accidental inoculation of minute amounts of blood or fluid
- during medical, surgical and dental procedures
- there is a 30-40% chance of transmitting the infection to a susceptible contact via a needlestick injury
- intravenous and percutaneous drug abuse
- account for over 20% of identified UK acute cases
- from razors and similar objects contaminated with infected blood
- use of inadequately sterilized syringes and needles
- tattooing; body piercing; and acupuncture
- perinatal transmission
- is a major route of HBV transmission in many parts of the world
- infection may transmit at the time of, or shortly after birth
- transmission in utero appears to be uncommon and is generally associated with antepartum haemorrhage and placental tears
- risk of perinatal infection is also increased if the mother has acute hepatitis B in the second or third trimester of pregnancy or within two months of delivery
- risk of developing chronic infection is 90% following perinatal infection (up to 6 months of age) but decreases to 20–60% between the ages of 6 months and 5 years (1)
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