Acute hepatitis A

　　Hepatitis A virus (HAV) is a member of the Picornaviridae family and belongs to the Hepatovirus genus. HAV has strong resistance and can withstand 56°C for 30 minutes and room temperature for a week. It can survive for 30 days at 25°C in dry feces, and for several months in shellfish, wastewater, freshwater, seawater, and soil. This stability is very favorable for the transmission of HAV through water and food.

　　The main route of transmission is fecal-oral, which can be transmitted through food, water, daily contact, and non-enteric transmission. When feces, urine, and vomit containing HAV are not disinfected, they can contaminate the surrounding environment, food, and water sources, or be transmitted through the hands of patients, healthy individuals, and virus-carrying flies, etc., thereby contaminating food, drinking water, and utensils.

　　High-pressure steam (121℃, 20 minutes), boiling for 5 minutes, ultraviolet radiation, formaldehyde (1:4000, 37℃, 72 hours), potassium permanganate (30mg/L, 5 minutes), iodine (3mg/L, 5 minutes), chlorine (free chlorine 2.0-2.5mg/L, 15 minutes), 70% alcohol at 25℃ for 3 minutes can all effectively inactivate HAV.

　　1. There are many extrahepatic complications of hepatitis A, with 9.7% of patients having rash, a type of skin lesion. It can range from simple changes in skin color to skin surface swelling or the formation of blisters, with a variety of manifestations. The rash is characterized by large and small red spots, and sometimes it may be itchy, and sometimes it may not be itchy. There are many types and causes, and diagnosis needs to be made according to different situations.

　　2. There are 33% of patients with proteinuria, which is due to the filtration function of the glomerular filtration membrane and the reabsorption function of the renal tubules. In healthy people, the content of protein in urine (usually referring to proteins with smaller molecular weight) is very low (less than 150 mg per day), and it shows a negative reaction in protein定性检查. When the content of protein in urine increases, it can be detected by a routine urine test, known as proteinuria. If the urine protein content is ≥3.5g/24h, it is called gross proteinuria.

　　3. There are 38.6% of patients with joint pain, which may be related to the formation of transient immune complexes in the serum of patients infected with HAV.

　　4. Some patients may have hepatic encephalopathy, aplastic anemia, viral myocarditis, Guillain-Barré syndrome, etc., and the mortality rate of hepatitis A is 15.2 per 100,000.

　　5. Complications of acute hepatitis are rare, among which cholecystitis is more common, and pericarditis and结节性多动脉炎 are occasionally seen.

　　The main symptoms include aversion to cold, fever, generalized weakness, decreased appetite, nausea, vomiting, aversion to oil, abdominal distension, pain in the liver area, and darkening of urine color. About one week later, some patients may develop these symptoms, followed by jaundice of the skin and conjunctiva. When anti-HAV IgM is positive, it can be diagnosed as acute infection. There may also be anorexia, abnormal liver function, and some patients may have fever and jaundice, and some may become chronic due to prolonged or recurrent episodes; a few may develop into severe hepatitis. Severe hepatitis is a dangerous disease with a high mortality rate. The main causes of death are hepatic coma, liver failure, electrolyte imbalance, and secondary infection. Hepatitis A and hepatitis E are mainly transmitted through fecal-oral route, common symptoms include fever and jaundice, and it is acute in nature, rarely becoming chronic.

　　The characteristics of this disease are acute onset, with the initial symptom being fever, which is usually tolerable and lasts for 1-2 days; at the same time or after the fever subsides, there may be fatigue and decreased appetite, in severe cases, nausea and vomiting may occur, which generally lasts for 5-7 days; then, red tea-colored urine appears, accompanied by jaundice of the eyes and skin, which is when the symptoms of fatigue and decreased appetite begin to alleviate, usually lasting for 2-4 weeks; then, jaundice subsides and the disease recovers. Hepatitis A is scattered throughout the year, mainly occurring from December to April, and is mainly seen in adolescents.

　　1. Develop good hygiene habits, wash hands before meals and after defecation, and do not share eating utensils.

　　2. Do not drink unboiled water and do not eat uncooked, cold, and unclean food.

　　3. Flush the toilet clean after defecation.

　　4. Keep the environment around the dormitory and classroom clean.

　　5. Wash hands and utensils clean at the end of the internship or practice, and disinfect if necessary.

　　6. Hotpot is delicious, and the ingredients should be boiled when eaten, and seafood should be boiled for a longer time.

　　7. Barbecues are delicious, and the ingredients are mostly frozen, so be cautious when using them.

　　8. Most food stalls around the college do not have a health license, so be cautious when eating.

　　9. Avoid contact with the source of infection, and those who may come into contact with it should report promptly.

　　10. You can go to the health station to get vaccinated against hepatitis A.

　　11. Learn about the prevention and treatment of type A hepatitis, enhance the awareness and ability of prevention.

　　12. If symptoms such as decreased appetite, nausea, aversion to oil, fatigue, jaundice of the sclera, tea-colored urine, liver enlargement, pain in the liver area, and fatigue appear recently, they should be reported and visited promptly.

　　13. The blood of patients in the acute stage must be handled with caution, and the feces of hepatitis A patients as a source of infection must be strictly treated.

　　1. Liver function test

　　Serum total bilirubin begins to rise in the pre-jaundice period, reaching a peak within 2 weeks; in severe and cholestatic types, it can reach above 171 μmol/L. Serum ALT begins to rise in the late latent period, and AST can also rise, with a significant prolongation of prothrombin time in severe cases and a progressive decrease in activity.

　　2. Specific immunological detection

　　Enzyme-linked immunosorbent assay (ELISA) is the most reliable method for diagnosing acute type A hepatitis by detecting anti-HAV IgM, which remains at a high titer within 8 weeks after the disease and continues until the early stage of recovery.

　　3. Blood and urine routine

　　Peripheral blood routine white blood cells are generally reduced or within the normal range, and may be accompanied by a slight increase in the proportion of lymphocytes or monocytes in the early stage of the disease. Urobilinogen in urine increases in the early stage of the disease, and bilirubin and urobilinogen both increase during the jaundice period. Liver function tests, such as serum ALT, AST, and total bilirubin levels, are the most useful. Studies have shown that the average peak value of ALT in patients with type A hepatitis can reach 1952 IU/L, and AST can reach 1442 IU/L, and most apparent infectious cases are accompanied by an increase in serum total bilirubin levels.

　　In the early stage of onset, easy-to-digest and light diet should be provided, but attention should be paid to the appropriate amount of calories, protein, and vitamins, and vitamin C and B-group vitamins should be supplemented. If the patient has a poor appetite and eats too little, glucose solution and vitamin C can be supplemented intravenously. After the appetite improves, a diet containing sufficient protein, carbohydrates, and appropriate amounts of fat should be provided, and high sugar and low-fat diet should not be emphasized, and excessive intake should be avoided.

　　Diet should be suitable for the patient's taste, easy to digest light food. It should contain a variety of vitamins, have enough calories, and an appropriate amount of protein. The protein intake should strive to reach 1-1.5g/kg per day, and appropriate supplementation of vitamin B group and C should be provided. When the amount of food intake is too little, glucose and vitamin C can be supplemented intravenously, and high sugar and low-fat diets are not emphasized.

　　Hepatitis A is a self-limiting disease, and treatment is mainly based on general and supportive treatment, supplemented by appropriate drugs, avoiding alcohol, fatigue, and hepatotoxic drugs. Emphasize early bed rest until symptoms are significantly reduced, and gradually increase activity, taking not feeling tired as the principle.

　　Drug-assisted therapy

　　Generally, it is not recommended to take too many drugs, increase vitamins C, E, K, and promote energy metabolism drugs such as adenosine triphosphate (ATP), coenzyme A, etc., and at the same time, drugs such as Isatis root, hepatitis bupleurum, Qili Ning, and traditional Chinese medicine formulas for clearing heat and dampness such as modified Yin Chen Hao Decoction can be used, for those with severe jaundice, Yin Zhi Huang injection can be used for intravenous drip, for those with severe gastrointestinal symptoms or nausea and vomiting, appropriate fluid supplementation should be supplemented, and comprehensive measures should be taken for severe hepatitis, including:

　　① Strengthen supportive therapy: Appropriately supplement fresh blood, fresh plasma, thrombin complex, and the like;

　　② Promote liver cell repair and regeneration: Use hepatocyte growth factors, glucagon-insulin (G-I) therapy;

　　③ Treatment of hepatic encephalopathy: Reduce the production and absorption of ammonia in the intestines, which can be taken orally by lactulose, adjust the ratio of bran to bran, and use bran-chain amino acids (hexapeptide) and the like;

　　④ Treatment of cerebral edema: Use 20% mannitol promptly and in sufficient quantity, 1-2g/kg each time, and 80ml of 50% glucose injection intravenously, every 6 hours, alternating use;

　　⑤ Prevent and control secondary infections: Use strong antibiotics with no toxicity to the liver and kidneys promptly if there is an infection, and be vigilant about secondary infections;

　　⑥ Correct water and electrolyte disorders;

　　⑦ Prevent renal insufficiency: Pay attention to supplementation when the blood volume is insufficient.