1) Why is HBV the most contagious in the attack?
Because of the obvious replication (reproduction) of HBV in the blood, the serological indicators are obviously abnormal, and the virological indicators are HBsAg positive, HBeAg positive and anti-HBc positive, commonly known as "Big Three Yang". Among them, HBeAg is the most contagious. For example, if HBeAg-positive blood is given to the recipient, or the HBeAg-positive blood accidentally pollutes the damaged skin of healthy people, HBV can enter the body through the blood. After a period of incubation, clinical symptoms will appear, such as fever, anorexia, nausea, vomiting, dark urine, and elevated ALT.
2) The main route of 2)HBV entering the blood:
1. Vertical mother-to-child transmission: There are about1.400 million HBsAg positive people in China, of which mother-to-child transmission accounts for 85%. Vertical transmission is the main reason for the spread and high incidence of hepatitis B in China. There are also some father-son communicators. Mother-to-child transmission is mainly through birth canal infection or intrauterine infection.
2. Transmission of blood or blood products: Most blood products contaminated by HBV, such as albumin, platelets or blood, will have hepatitis after blood transfusion, and HBV will also be infected during hemodialysis and renal dialysis.
3. Iatrogenic transmission: medical instruments contaminated by HBV (such as scalpels, dental drills, endoscopes, laparoscopy, etc. ) can spread HBV.
4. Close family contact: it mainly refers to sexual contact and close contact in daily life (such as using toothbrushes, towels, teacups and chopsticks), which may be infected by HBV. HBV can enter the body of close contacts through the damaged mucosa.
5. Public places, barber shops, beauty salons, etc. It is easy to be contaminated by HBV, such as bathtubs and razors.
3) How to prevent HBV infection?
First of all, mother-to-child transmission is the main route of transmission of hepatitis B in China, which has been highly valued in China. Since 1980s, infants born to HBsAg-positive pregnant women have been injected with hepatitis B vaccine. After 20 years' efforts, the proportion of HBsAg carriers among babies born in Shanghai has dropped from 9.8% to 0.5%. Therefore, we can proudly say that in the near future, the number of HBsAg carriers in China will be significantly reduced, and hepatitis B is completely preventable. Secondly, strictly screen blood donors to ensure that medical blood and blood products are not contaminated. Finally, to strengthen the treatment of patients with hepatitis B, interferon-α is the first choice for chronic active hepatitis B, and to strengthen the popularization of health knowledge and develop good health habits. Through the above measures, I believe that in the near future, the number of patients with hepatitis B will be greatly reduced.