Hepatitis is contagious! Which routes of transmission need to be guarded against?
There are five kinds of liver infection viruses confirmed by clinical research. the liver disease caused by virus mainly refers to viral hepatitis, that is, the liver inflammatory reaction directly caused by various hepatitis viruses and how the virus invades the liver and infects hepatitis A. Hepatitis A virus can be cleared by the immune response of the body. Generally, it will not develop into chronic hepatitis, liver cirrhosis or viral carrier state. The hepatocyte damage of hepatitis B is mainly caused by a series of immune responses of the body. If the hepatocytes infected by hepatitis B virus are destroyed by immune response, it is possible to show asymptomatic chronic hepatitis B virus carriers in the pathogenesis of hepatitis C and E. The pathogenesis of hepatitis C and E is also related to the immune response of the body. the injury of hepatocytes is mainly caused by the immune response of the body. Hepatitis D virus has a direct pathogenic and destructive effect on hepatocytes, which can lead to a large number of hepatitis D virus replication.
The liver is not only the largest substantive organ of the human body, but also the largest digestive organ in the digestive system.It sounds like a "hard core", but it is also fragile, especially in front of the virus.Up to now, there are 5 kinds of liver infection viruses confirmed by clinical studies, all of which can directly cause serious liver diseases.
Which liver diseases are caused by viruses?
At present, the liver disease caused by virus mainly refers to viral hepatitis, that is, liver inflammation caused directly by various hepatitis viruses, including hepatitis A, hepatitis B, hepatitis C, hepatitis D and hepatitis E.
Any kind of hepatitis develops to a certain extent, it will cause serious damage to the body, and even threaten life.China is a large country with hepatitis B, and about 10% of the population are hepatitis B patients.Long-term suffering from hepatitis B and C will cause liver cirrhosis; liver cancer will occur after the malignant transformation of liver cirrhosis nodules. Therefore, the harm of hepatitis B and C is relatively greater in our country.
How does the virus attack the liver?
When infected with hepatitis A, hepatitis A virus replicates and proliferates in hepatocytes, and the body will appear a series of immune responses, resulting in hepatocyte damage, such as hepatocyte necrosis and inflammation.Hepatitis A virus can be cleared by the immune response of the body, generally will not develop into chronic hepatitis, liver cirrhosis or viral carrier state.
The pathogenesis of hepatitis B is very complicated. When infected with hepatitis B virus, hepatitis B virus replicates in hepatocytes, although it does not directly cause hepatocyte pathological changes, butHepatitis B virus gene can be integrated into the host hepatocyte chromosome, resulting in long-term consequences.The hepatocyte injury of hepatitis B is mainly caused by a series of immune responses of the body, which can not only eliminate the virus, but also lead to hepatocyte damage, and even force hepatitis B virus to mutate.
Whether the immunomodulatory function of the body is normal or not and the strength of immune response are closely related to the clinical type and prognosis of hepatitis B. In the body with normal immune response and immunomodulatory function, the hepatocytes infected by hepatitis B virus are destroyed by immune response.The infection was terminated by the death of hepatocytes, and the clinical manifestation was a smooth recovery of acute hepatitis.According to the amount and strength of the virus, the degree of hepatocyte damage is different, and acute hepatitis is characterized by acute jaundice or acute non-icteric hepatitis.
If the body immune function and clearance of hepatitis B virus function is low, hepatitis B virus has not been completely eliminated, it may be asymptomatic chronic hepatitis B virus carriers.Some patients' liver function is constantly slightly damaged, manifested as chronic persistent or active hepatitis.
At present, little is known about the pathogenesis of hepatitis C and E. The results suggest that the pathogenesis of hepatitis C and E is also related to the immune response, and the injury of hepatocytes is mainly caused by the immune response.
The study of hepatitis D shows that hepatitis D virus has a direct pathogenic and destructive effect on hepatocytes.The superinfection of hepatitis D and hepatitis B can lead to a large number of replication of hepatitis D virus and significantly aggravate the damage of hepatocytes.It is easy to develop into chronic hepatitis or severe hepatitis.
Which transmission routes need to be guarded against?
The most common form of transmission of hepatitis A virus isFecal-oral pathway, also known as intestinal pathwayThat is, contaminated food and water enter the digestive tract and cause hepatitis An infection. Crustaceans living in water are likely to be contaminated with hepatitis A virus.When people eat undercooked oysters, clams, oysters and other aquatic products, there is a higher risk of contracting hepatitis A virus.The main population of hepatitis An infection is children and adolescents, and the peak of hepatitis An is in winter and spring.
The routes of transmission of hepatitis B / C include blood transmission, mother-to-child transmission, close contact transmission and iatrogenic transmission.
(1) Blood transmission:A very small amount of blood or blood products containing hepatitis B or C virus can cause infection after entering the human body, and can be transmitted by blood transfusion, hemodialysis and organ transplantation.
(2) mother-to-child vertical transmission:If the mother is a carrier of hepatitis B or C virus, then there is a certain probability of transmission to the fetus before and after delivery.
(3) sexual transmission:Have unprotected sexual contact with patients infected with hepatitis B virus, and hepatitis B virus can be transmitted through damaged skin and mucosa.
(4) iatrogenic transmission:The use of contaminated needles or needles with lax disinfection in medical work can cause artificial transmission of hepatitis B or C virus.
Hepatitis D virus and hepatitis B virus have the same route of transmission, that is, through blood, sexual contact and mother-to-child transmission. But...Hepatitis D virus is rarely infected alone, and it is often co-infected with DNA virus such as hepatitis B virus.
Hepatitis E, like hepatitis A, is also transmitted through the fecal-oral route. In the past, water epidemic was the most common, seasonal, mostly after the rainy season or flood, and more common in people with a history of unclean eating. The disease is mainly young and middle-aged, pregnant women are more susceptible to severe hepatitis E, and the case fatality rate is high.
Special reminder
It should be emphasized that there is no daily exposure to blood exposure.Such as working with hepatitis B / C patients, shaking hands and hugging, living in a room, or even eating together and sharing toilets, in theory, will not be infected.However, if it is intimate contact, such as marriage, then it is recommended to carry out various hepatitis virus tests before marriage. If it is positive, you should be treated as soon as possible, for yourself, for your lover, and for the health of the next generation.
Author: Wang Xuedong, Deputy Director of Hepatobiliary and Pancreatic Center, Tsinghua Chang Gung Memorial Hospital, Beijing
Audit: national expert database of health science popularization experts
Lang Ren, chief physician of hepatobiliary surgery, Beijing Chaoyang Hospital affiliated to Capital Medical University.
Planner: Tan Jia
Editor: Yu Yunxi