Hepatitis B is a blood-borne infectious disease. Hepatitis B virus is transmitted by one person, and it is usually infected by people. Hepatitis B virus is not as explosive as influenza virus, but it has tenacious vitality and hidden transmission mechanism. In this way, the cumulative number of infected people in the country is 654.38+0.2 billion. In recent years, due to the wide application of hepatitis B vaccine, the cumulative number of people infected with hepatitis B has dropped below 654.38+0 billion. Among these people, those who are infectious and can spread hepatitis B virus to others are called "sources of infection". Infectious depends on the level of virus in the blood. Chronic hepatitis B virus carriers in "Big Three Yang" have active virus replication in their bodies, and the virus level in their blood is relatively high, which is the most active source of infection. The undetected carriers of "Sanyang" hidden in the crowd are the most potentially contagious. But not all people infected with hepatitis B virus are the source of infection. The chronic hepatitis B virus carriers in "Xiao Sanyang" have virus in their liver, but the replication level is very low, and hepatitis B virus can not be detected in their serum, so the carriers are less contagious. The infectivity has nothing to do with the level of serum transaminase. Viruses are contagious, not transaminase. The spreading potential of the source of infection also depends on his work or lifestyle and his close contact with others. Daily contact with carriers is not contagious. Infection needs certain routes, mainly blood transmission, sexual contact and mother-to-child transmission, and of course it also includes iatrogenic transmission, including surgery, dental instruments, blood collection needles, acupuncture needles and endoscopes. Hepatitis B virus is a blood-borne virus, and different transmission routes should take blood as the carrier. In recent years, China's blood transfusion management is very strict, and blood transfusion transmission is very rare; At present, "micro-blood inoculation" is more common, such as tattoo, eyebrow tattoo, shaving, drug abuse and so on. , hidden because of infection. As the saying goes, we tend to magnify the risks we know infinitely, but we are insensitive to the unknown risks. When we know that the other party has hepatitis B virus infection, we are often particularly taboo, but we don't know that tattoos and barbers' razors can also cause recessive transmission. This sign is often ignored. Mother-to-child transmission used to be the most important route, which has been largely blocked due to the universal vaccination of hepatitis B vaccine. Mother-to-child transmission includes two aspects, one is vertical transmission, and the other is horizontal transmission. People always think that mother-to-child transmission is vertical transmission, but it is not. Only 65,438+00% is caused by intrauterine transmission, and only 65,438+00% is infected in the uterus during pregnancy, which is not very high. Mainly in horizontal transmission, which is in close contact during the perinatal period and after birth. As a "three-positive" mother, the probability of being infected after birth is 90%-95%, and the probability of children born to hepatitis B mothers with negative E antigen is half lower than that of mothers with positive E antigen, which is about 45%-40%. Close contact and transmission in daily life is mainly due to contact with objects contaminated by patients' blood. For example, "Big Three Yang" carriers release a large amount of hepatitis B virus to pollute the environmental surface due to skin abrasion and damage, and can survive in vitro for a long time, and then be infected by the damaged skin of susceptible people. Infection caused by mucosal injury during sexual life. In Europe and America, sexual contact is the most important way for adults to spread hepatitis B virus. Hepatitis B cannot be counted as a sexually transmitted disease in China. There are huge hepatitis B carriers in China. They live around and have close contact with everyone. Everyone needs to communicate. Can you be infected with hepatitis B virus when you are with hepatitis B carriers? Of course not. None of the following behaviors will cause the spread of hepatitis B virus: 1. Have dinner together. As I said before, the digestive tract cannot spread hepatitis B, nor can eating with hepatitis B carriers spread hepatitis B virus. However, there are always some people in society who are "afraid". If they know who is the carrier of hepatitis B, they will be excluded. Shake hands with each other. Although HBV markers may be detected in the sweat of HBV carriers, shaking hands is still safe. In fact, healthy people's hands can be contaminated by a variety of microorganisms. Some people find thousands of germs and viruses on their hands, but they don't get sick. These germs and viruses just "hurried by". It doesn't mean that germs and viruses will definitely get sick if they fall into your hands. The human body itself still has disease resistance, and sweat also contains an acid, which is not conducive to the growth of germs and viruses. You should pay attention to washing your hands, which is even less of a problem. 3. Courtesy kissing. The saliva of hepatitis B carriers may contain hepatitis B virus, but ceremonial kissing is not polluted by saliva, which belongs to "dry kissing", even if the lips touch. The mixing of saliva between lovers may have a certain communication effect, but it is of little practical significance. Because the probability of contracting hepatitis B virus from oral cavity is very small, many scholars' experiments have proved that it is difficult for hepatitis B virus to spread successfully in oral cavity. 4. hug each other. This is a common polite behavior, because without substantial contact, it is impossible to spread hepatitis B virus. It's just that some people always feel that the other person is a carrier of hepatitis B, which is psychologically difficult to accept. Dance. Dancing together may have hand-in-hand movements, which is not enough to constitute the spread of hepatitis B virus. In fact, on the dance floor, no one knows who it is. Maybe your partner is a hepatitis B carrier. However, as long as you know that the other person is a hepatitis B carrier, you will never want to dance with others again. This is purely spiritual. 6.*** Same as games and travel. Eating in the wild, helping each other and talking and laughing can not cause the spread of hepatitis B virus. There is a simple reason. There is no transmission channel between the virus in the body of hepatitis B carriers and each other, but only general contact. How does hepatitis B virus enter each other's blood? The natural environment is by no means a place to spread hepatitis B virus. 7. Live in the same room. Students are in a dormitory, among which there are hepatitis B carriers, and they will not infect each other. Hepatitis B virus cannot survive and replicate in the air. Each pathogen and virus has its own unique transmission channel. Hepatitis B virus is mainly transmitted through blood channels and will not invade people from the respiratory tract. Even if the other person sneezes or coughs, it does not constitute an infection. 8. Have classes in the same classroom. This is also very safe and will not spread hepatitis B.