Hepatitis B, referred to as hepatitis B, is a disease caused by hepatitis B virus (HBV) infection. According to the course of disease, it can be divided into acute hepatitis B B and chronic hepatitis B, while chronic hepatitis B refers to HBV infection that lasts for more than half a year. Professor Gao Zhiliang, vice president of the Liver Disease Hospital of the Third Affiliated Hospital of Sun Yat sen University, said that if people do not intervene as soon as possible after being infected with HBV, they will develop into chronic hepatitis B. Chronic hepatitis B is a common cause of liver cancer and one of the major public health problems facing China. Chen Xingdong, a researcher at the Institute of Human Phenotypes at Fudan University, found that the HBV infection rate in the general population of China is showing a significant downward trend, with children under 5 years old experiencing the fastest decline, but the HBV infection rate is on the rise in the elderly population over 60 years old. The research results were recently published online in the Journal of Gastrointestinal Tract. How about the infectivity and incidence rate of hepatitis B? What achievements has China made in solving the problem of chronic hepatitis B? What is the direction of future prevention and control? With these questions in mind, a reporter from Science and Technology Daily interviewed relevant experts. Mother to child transmission is the main route of infection. hepatitis B is infectious, mainly through mother to child, blood and sexual contact. The degree of infectivity mainly depends on the degree of HBV replication. According to statistics, at present, mother to child transmission is the main route of transmission of hepatitis B in China, accounting for 40% -50% of new infections, mostly in the perinatal period, that is, from the 28th week of pregnancy to the week after the birth of the fetus. Lu Mingqin, director of the Department of Internal Medicine of Infection of the First Affiliated Hospital of Wenzhou Medical University, said that the mother's level of hepatitis B virus deoxyribonucleic acid (HBV DNA) was closely related to the risk of neonatal infection with HBV. The mother with positive hepatitis B virus e antigen (HBeAg) and high level of HBV DNA was more likely to make the baby infected with HBV. For adults, HBV is mainly transmitted through blood and sexual contact, including transfusion of blood and blood products that have not been strictly screened and tested, non-standard blood purification, non-standard invasive procedures (such as injections, surgeries, and dental diagnosis and treatment procedures), and unprotected sexual behavior. "Normal contact in daily life will not infect people with HBV." Lu Mingqin stressed that HBV does not spread through the respiratory tract and digestive tract, working in the same office or sharing computers with hepatitis B patients or HBV carriers, living in the same dormitory, dining in the same restaurant, sharing sanitary rooms, shaking hands, hugging and other contacts without blood exposure will not infect people with HBV. Some hepatitis B patients can achieve clinical cure. The World Health Organization announced that in 2019, the global general population hepatitis B prevalence rate was 3.8%, with about 1.5 million new HBV infected people and 296 million chronic HBV infected people. In 2014, the survey results of the China Center for Disease Control and Prevention showed that the positive rate of hepatitis B surface antigen (HBsAg) among people aged 1 to 29 years old in China was 2.94%, and that of children under 5 years old was 0.32%. "The main strategy of hepatitis B prevention is to cut off the transmission routes and protect vulnerable people." Lu Mingqin said that in China, mother to child transmission is the main transmission route of hepatitis B. Therefore, if women of childbearing age find indications for antiviral treatment, they should actively carry out