Hepatitis virus prevention and treatment
Hepatitis virus prevention and treatment
Hepatitis viruses are a group of pathogens that primarily invade the liver to cause viral hepatitis, some of which can also cause damage to the brain, lungs and heart.
Principle
There are currently five recognized human hepatitis viruses, including hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV), which belong to different viral families and genera. Hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis E virus (HEV) belong to different virus families and genera. They belong to different viral families and genera, and can be divided into two categories according to their transmission routes and pathogenic characteristics: one category is mainly transmitted by fecal-oral route, including HAV and HEV, which causes acute hepatitis and does not develop into chronic hepatitis or chronic carriers; the other category is mainly transmitted through blood exposure and sexual route, including HBV, HCV and HDV, which, in addition to causing acute hepatitis, can also be chronicized and develop into cirrhosis or even hepatocellular carcinoma. The biological characteristics of these hepatitis viruses are different, and the diseases caused by them are somewhat similar.
Operation method
Prevention and treatment of hepatitis viruses
Principle
The principles of hepatitis treatment are divided into general management and drug treatment. The former includes rest and nutrition, while the latter is centered on antiviral therapy, which can be supplemented with hepatoprotective, enzyme-lowering and immune-enhancing drugs. Antiviral drug therapy is aimed at HBV and HCV infections.
Materials and Instruments
Equipment: feces Move I. HAV and HEV HAV and HEV are mainly transmitted orally through fecal contamination of food and water, therefore, good hygiene education and strengthening of food, water and fecal management are the main links in the prevention of Hepatitis A. The patients' excreta should be strictly sterilized. Patients' excreta, eating utensils, articles and bedclothes should be strictly sterilized. Active immunization: Currently, the main vaccines that can successfully prevent hepatitis A are inactivated and live attenuated vaccines. Inactivated vaccines have been applied to the prevention of hepatitis A in high-risk groups. They are safe, highly immunogenic, and antibody titers can rapidly reach a level sufficient to prevent infection. The live attenuated vaccine can induce the production of protective antibodies with little toxic side effects. The HAV live attenuated vaccine H and LA-1 developed successfully in China is made by successive passaging of HAV isolated from patients' feces through the diploid cell line of human embryonic lungs, which has a good immunity effect and can obtain long-lasting immunity after inoculation, and has been used on a large scale in China at present. New types of HAV vaccines such as genetically engineered vaccines and multi-epitope vaccines are under development, and there is no effective vaccine for HEV infection at present. Passive immunization: human blood gammaglobulin and human placenta globulin have a certain protective effect on the early application of hepatitis A contacts, which is mainly applicable to susceptible children exposed to hepatitis A patients. HAV and HEV infections are self-limiting diseases, and patients with hepatitis A generally do not need specific antiviral therapy, and the main treatment measures are symptomatic supportive therapy. HEV infection has no specific antiviral drugs for prevention and treatment, and most patients with hepatitis E improve and recover about 6 weeks after the onset of the disease, without developing chronic hepatitis or viral carriers. Anti-HEV IgC usually becomes positive about 4 weeks after the onset of the disease, and most patients gradually disappear after 5-6 months. Therefore, even if HEV has been infected in childhood, it can be re-infected after young adulthood.
(I) Prevention
At present, the prevention strategies and measures for HBV, HCV and HDV are the comprehensive preventive measures to protect susceptible people, manage infectious sources, cut off transmission routes and provide health education. 1. specific immunoprophylaxis protects susceptible people, manages infectious sources, cuts off transmission routes and provides health education.
1. Specific immunoprophylaxis protects susceptible people. At present, most countries worldwide apply recombinant gene vaccine to prevent hepatitis B and HBV infection. The protection rate of hepatitis B vaccine is reported to be around 90% in different places after routine three injections, and the protection period of normal responders (anti-HBs at the peak of antibody response is more than 10 mU/ml) is generally considered to be up to 5~15 years at present. Newborns and high-risk groups are the first choice for hepatitis B vaccination. In some countries and regions, vaccination has been extended to adolescents who have not received hepatitis B vaccine. In hyperendemic areas, hepatitis B vaccination should be extended to the general population.
HBIG can provide rapid, specific passive immunoprophylaxis, but its protective effect can only last 3-6 months, and it is mainly used for interruption of mother-to-child transmission and emergency prophylaxis after accidental exposure.
HCV is not highly immunogenic and is highly susceptible to mutation, which makes vaccination difficult, and the vaccine is still in the development stage.
HDV and HBV have a common transmission route, and HDV and HBV have a common envelope protein, through the HBV vaccine can achieve the purpose of preventing HDV infection. 2.
2. Management of infectious sources: Hepatitis B patients and asymptomatic HBsAg carriers are important infectious sources, which form a large number of HBV infections in China through horizontal and vertical transmission, and are the focus of prevention. They are managed according to the Law of the People's Republic of China on Prevention and Control of Infectious Diseases, including management of hepatitis B patients, management of HBsAg carriers and management of blood donors. 3.
3. To cut off the transmission pathway and prevent medical transmission, medical and health units at all levels should strengthen the disinfection and protection measures, and enhance the hygienic management of hemodialysis wards and the management of blood products. Testing of blood donors and blood products for HBV and HCV can greatly reduce infection and transmission. In order to block mother-to-child transmission, HBsAg should be taken as a routine prenatal examination item, and fetal injuries should be carefully prevented during delivery to prevent mother-to-blood transmission. The combined immunization of HBIG and hepatitis B vaccine should be applied to prevent HBV transmission. 4.
4. Health education: Health education should be strengthened for infectious sources, high-risk groups and the general population through various channels, especially for poor areas, migrant population, drug addicts and prostitutes. Health education can not only enhance the ability of the general public to prevent and control the transmission of the virus, but also is very important to increase the vaccination rate of HBV.
(ii) Treatment
At present, the treatment of chronic hepatitis B mainly includes antiviral, immunomodulation, anti-inflammatory and antioxidant, anti-fibrosis and symptomatic treatment, of which antiviral treatment is the key, and standardized antiviral treatment should be carried out as long as there are indications and the conditions permit. In order to standardize the prevention, diagnosis and treatment of chronic hepatitis B, the Division of Hepatology and the Division of Infectious Diseases of the Chinese Medical Association organized domestic experts to formulate the Guidelines for the Prevention and Treatment of Chronic Hepatitis B in 2005, with the following general objectives: to maximize the long-term suppression of HBV, to reduce the inflammation and necrosis of hepatocytes and hepatic fibrosis, and to slow down and reduce the occurrence of hepatic failure, cirrhosis, hepatocellular carcinoma and their complications, thus improving the quality of life and prolonging survival. This will improve the quality of life and prolong the survival time.
At present, the U.S. FDA has allowed the clinical application of five oral anti-HBV nucleoside (acid) analogs (lamivudine, adefovir, telbivudine, tenofovir and entecavir) and two injections (regular interferon and polyethylene glycolated interferon), and our country has already marketed the first four nucleoside analogs and two interferons. However, the incidence of resistance to antiviral therapy is very high and is the main reason for failure of antiviral therapy for chronic hepatitis B infection and should be monitored.
For HCV, antiviral therapy can cure some patients, and those who cannot be cured can delay the occurrence of liver fibrosis.IFN-α has a high efficiency for early chronic HCV infection, and the current recommended treatment for chronic hepatitis C is the combination of polyethylene glycolized IFN-α and ribavirin. Antiviral therapy medications and regimens vary by genotype, so HCV genotyping is necessary prior to interferon-based therapy to assist in the development of a personalized regimen, the selection of appropriate drug dosage and regimen, and the assessment of prognosis.
There is currently no effective treatment for hepatitis D virus infection.
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