Such as unclean injection, transfusion of contaminated blood and blood products, and iatrogenic transmission caused by the use of incompletely disinfected medical devices.

3. Contact route of transmission

If a toothbrush and a beard knife are used together, saliva is also of great significance in transmission. Others, such as bile, milk, urine, semen, menstrual fluid, hemodialysis, etc. , can become a medium of communication. Oral transmission must cause infection through the damage of oral or digestive tract mucosa or ulcer surface.

4. Mother to child transmission

This type is also an important mode of transmission of hepatitis B. If the mother is HBsAg and HBeAg positive, then the mother will transmit the virus to the newborn through pregnancy and delivery.

5. Transmission route from father to baby

HBV-DNA in sperm can be free or integrated. Free HBV-DnA can exist in sperm plasma cells, enter egg cells when fertilized, and may continue to replicate in offspring cells without being rejected, which may be a mechanism of father-infant transmission.

6. Other modes of communication

Mosquitoes and other blood-sucking insects may carry hepatitis B virus and also play a role in the spread of hepatitis B.