Hepatitis A is a viral hepatitis caused by the hepatitis A virus (HAV), which is mainly transmitted through the fecal-oral transmission route, i.e., the hepatitis A virus in the patient’s incubation period or acute phase of feces, blood contamination of water, food, utensils and close contact with the gastrointestinal tract through the mouth.
Hepatitis A virus has strong resistance to various external factors and can survive in the external environment for a long time. It can be transmitted through various contaminated objects (hands, daily necessities, clothes, sheets, etc.) as well as water and food, and can also be carried by flies. It is one of the common intestinal infectious diseases in China and has the highest incidence and infection rate among viral hepatitis.
Mode of infection
Hepatitis A is mainly contracted through unclean diet and drinking raw water, and the hepatitis A virus mainly takes humans, macaques, apes and other primates as hosts. A few may develop tea-colored urine or be told that they have jaundice, and their complications are more likely to include skin rash, proteinuria, and joint pain.
Prevention of hepatitis A
The focus of general prevention.
First of all, pay attention to daily dietary hygiene, which is an important measure to prevent food-borne infection, such as the usual cooking must be cleaned and cooked dishes; when eating hot pot, pay attention to fully heating, cooked and thoroughly cooked meat food, and try not to eat raw seafood; when eating snacks and fruits, pay attention to the cleanliness of food and drink boiled water.
Secondly, we should arrange our lives scientifically and reasonably, pay attention to the combination of work and rest, pay attention to the nutrition of the diet, but also pay attention to strengthen physical exercise, improve the poor lifestyle, improve physical fitness and immunity.
Third, we should pay attention to the early detection, early diagnosis and early treatment of the disease. If you have had contact with hepatitis A patients recently, or feel symptoms such as obvious weakness, poor appetite, aversion to oil, deep yellow urine, vague pain in the liver area, etc., and still do not get better after rest and no other explanation can be found, you should go to the hospital in time.
The patient gets timely isolation and treatment, it reduces the chance of others being infected and is also an important preventive measure. Fourth, hepatitis A is better protected by inactivated vaccine or live attenuated vaccine injection, and gammaglobulin can be passively immunized for 2 to 3 months.
Fundamentally, we should develop the economy, improve the material and cultural living standards of the people, improve the living conditions, popularize the general knowledge of hygiene, and improve environmental and personal hygiene.
Manage the source of infection well. Early detection of patients, especially in hepatitis A endemic areas, not only isolates the presenting patients, but more importantly, early detection and isolation of latent infected persons around the presenting patients.
Cutting off the transmission route is an important part of preventing this disease. Strengthen the management of diet, water sources and feces, develop good hygiene habits, wash hands before and after meals, disinfect shared utensils, preferably implement meal sharing, and strictly separate raw food from cooked food cutting boards, knives and storage containers to prevent contamination.
Protection of susceptible persons includes both passive and active immunization.
Passive immunization: Intramuscular injection of gammaglobulin at a dose of 0.02-0.05 ml per kg of body weight should be given to close contacts in the family, especially infants and children, within one week after contact, which has a certain preventive effect.
Active immunization: Live attenuated vaccine and inactivated vaccine for hepatitis A have been successfully developed, and animal experiments and human applications have proved that they can produce protective antibodies and can be widely used.
The inactivated hepatitis A vaccine researched and applied in recent years has high purity, low non-reactivity and a storage period of up to 3 years. After vaccination, the protection effect is high, and the protection period can be more than 20 years, and the safety is good, but because it is expensive, the widespread use is limited. Both vaccines are safe and effective, and the cost of domestic inactivated hepatitis A vaccine is lower than that of imported similar vaccines, but live attenuated vaccine has more advantages in terms of price.
Now, the two vaccines exist and are applied in China at the same time, which can complement each other and meet our national conditions. The future trend is to research and develop genetic recombinant vaccine, which has been successfully developed in China and has good effect after animal testing, and is now in the stage of human testing and observation.
Precautions for daily life to prevent hepatitis A
1, to develop good hygiene habits, to keep the “disease from the mouth” off.
Wash your hands before and after meals, do not drink raw water, do not eat or eat less cold food, eat fruits, lettuce and other fruit and vegetable foods must be cleaned, leftover food should be stored in the refrigerator, and should be fully heated before eating again. Especially when processing food to pay attention to high-temperature heating, in general, heating 100 ℃ for one minute can make the hepatitis A virus inactive.
2, to some of their own easy to carry pathogenic bacteria food such as snails, shells, crabs, especially can be enriched with hepatitis A virus ark and other sea, aquatic products, eat must be cooked and steamed through, to eliminate raw food, half raw food and pickled directly after eating and other bad eating habits.
3, to manage the “water pipe”, “manure pipe”, improve drinking water hygiene. Do not contaminate water with feces and sewage, do not use fresh feces in the field, do not wash the clothes of hepatitis A patients in the river or pond. Do a good job of harmless treatment of feces.
4. Pay attention to the elimination of flies, cockroaches and other pests to avoid the spread of disease vectors.
5, improve food hygiene, tableware and teaware disinfection. It is best to implement meal sharing, raw food and cooked food cutting boards, knives and storage containers should be strictly separated to prevent pollution. Do not go to small restaurants or roadside itinerant vendors without health permits and inadequate sanitation facilities.
6.People with elevated body temperature and symptoms such as weakness, anorexia, nausea, vomiting, jaundice, etc. should go to the hospital intestinal clinic in time for early diagnosis, early reporting, early isolation, early treatment, the more you can reduce the risk of infecting others. Hepatitis A patients should be isolated for three weeks from the date of onset of the disease, and their living rooms, active rooms and clothing should be disinfected. Patient contacts are placed under medical observation for 45 days.