甲型病毒性肝炎

　　甲型肝炎病毒HAV是小核糖核酸病毒科的一员，为嗜肝RNA病毒属。HAV经口进入体内后，经肠道进入血流，引起病毒血症，约过一周后到达肝脏，随后通过胆汁排入肠道并出现粪便中。粪便排毒能维持1-2周。病毒侵犯的主要器官是肝脏，咽部和扁桃体可能是HAV肝外繁殖的部位。HAV引起肝细胞损伤的机制尚未明确，一般认为HAV不直接引起肝细胞病变，肝脏损害是HAV感染肝细胞的免疫病理反应所引起的。

　　1. Sources of infection

　　Hepatitis A patients and asymptomatic carriers are the sources of infection. Hepatitis A patients mainly excrete the pathogen in feces, while HAV is mainly present in the blood 14-21 days before the onset of jaundice. During this period, the blood of patients is infectious. There have been reports of transmission through blood transfusion, but the blood of patients usually is not infectious after the onset of jaundice. The largest amount of HAV is excreted in the feces of patients 2 weeks before the onset and 1 week after the onset, and this is when the infectivity is strongest. However, a small number of patients still excrete HAV in the feces 30 days after the onset.

　　2. Modes of transmission

　　Hepatitis A is primarily transmitted through the fecal-oral route, with various modes of transmission. Generally, daily contact transmission is the main mode of sporadic onset, and therefore, the incidence of hepatitis A is high in collective units such as kindergartens, schools, and military units. The transmission of water and food, especially shellfish such as clams, is the main mode of outbreak and epidemic transmission of hepatitis A.

　　3. Susceptibility and immunity

　　People who have not been vaccinated against hepatitis A are generally susceptible to HAV. Individuals who have had hepatitis A or been infected with the hepatitis A virus can develop long-lasting immunity.

　　Hepatitis A has many extrahepatic complications, with 9.7% of patients developing rashes, 33% experiencing proteinuria, and 38.6% suffering from joint pain. The appearance of symptoms may be related to the formation of transient immune complexes in the serum of patients infected with HAV. Some patients may also have hepatic encephalopathy, aplastic anemia, viral myocarditis, Guillain-Barré syndrome, and the mortality rate of hepatitis A is 15.2 per 100,000.

　　At the beginning of hepatitis A, patients may experience fatigue, loss of appetite, darkening of urine color, and sometimes fever, with yellowing of the sclera and skin in severe cases. Clinically, it is divided into two types: overt infection and asymptomatic infection. Adult infections often manifest as overt infection, while children or the elderly are more likely to show asymptomatic infection.

　　1. Acute jaundice type

　　(1) Incubation period: The incubation period for hepatitis A is 15 to 45 days, with an average duration of 30 days. Patients usually do not have any自觉 symptoms during this period, but in the latter part of the incubation period, about 25 days after infection, a large amount of HAV is excreted in the feces, and the infectivity of patients during the incubation period is the highest.

　　(2) The acute onset of jaundice may be accompanied by fever and aversion to cold, with body temperature ranging from 38 to 39 degrees Celsius. The average duration of fever is 3 days, with a few cases lasting up to 5 days. Symptoms may include general weakness, loss of appetite, dislike of oil, nausea, vomiting, a feeling of fullness in the upper abdomen, or mild diarrhea. A few patients may present primarily with symptoms of upper respiratory tract infection, with urine color gradually deepening to a dark tea color. This phase lasts for 5 to 7 days.

　　(3) During the jaundice period,自觉症状 improve, jaundice appears after the fever subsides, with varying degrees of yellowing of the sclera and skin, pain in the liver area, liver enlargement, tenderness and percussion pain, and some patients have splenomegaly. There may be a temporary lightening of stool color and pruritus. Liver function is significantly abnormal. It lasts for 2 to 6 weeks.

　　(4) Jaundice during the recovery period gradually subsides, symptoms improve and eventually disappear, the liver and spleen shrink back to normal, liver function gradually returns to normal, and the IgG-mediated immune system is established. This period lasts for 2 weeks to 4 months, averaging 1 month.

　　2. Acute non-jaundice type

　　Less common than the jaundice type. The onset is slower, with milder clinical symptoms, only showing fatigue, decreased appetite, pain in the liver area, and abdominal distension. Signs often include liver enlargement, mild tenderness and percussion pain, and rare splenomegaly. Transaminases are elevated. It usually recovers within 3 months.

　　3. Cholestasis type

　　Formerly known as capillary cholangitis, it is now proven that the primary pathological change is in the biliary excretion mechanism of liver cells, not in the capillaries, so the original name is no longer used. It is mainly caused by the liver cell lysis induced by acute hepatitis A, leading to decreased bile secretion, increased bilirubin levels in the blood, and increased bile acid concentration, causing jaundice and pruritus all over the body. The onset is similar to acute jaundice hepatitis, but the gastrointestinal symptoms are milder. The disease course is long, with jaundice lasting for 2 to 4 months.

　　This type is a special manifestation of jaundice, with the clinical characteristic of mild gastrointestinal symptoms, prolonged fever, persistent obstructive jaundice within the liver for a long time (several weeks to several months), with symptoms such as abdominal distension, pruritus, transiently lighter stool color, dark urine resembling strong black tea, liver enlargement, and tenderness. It needs to be differentiated from other intrahepatic and extrahepatic obstructive jaundices.

　　4. Subclinical type

　　Some patients may not have obvious clinical symptoms, but their liver function may be slightly abnormal.

　　5. Severe hepatitis

　　Less common. The older the age of adults infected with HAV, the higher the proportion of severe hepatitis A cases.

　　6. Fulminant hepatitis A

　　This type accounts for 0.1% to 0.8% of all cases, but the mortality rate is very high, reaching 50%. This type has a very acute onset, with obvious symptoms of gastrointestinal and systemic intoxication, such as fever, loss of appetite, nausea, frequent vomiting, and extreme fatigue; jaundice gradually deepens, the liver progressively shrinks, with a tendency to bleed, toxic megacolon, liver odor, ascites, acute renal failure, and varying degrees of hepatic encephalopathy, eventually leading to deep coma and convulsions. Patients often die from cerebral edema, cerebral hernia, gastrointestinal bleeding, liver and kidney failure, and the course of the disease does not exceed 3 weeks.

　　Hepatitis A virus (HAV) is a member of the Picornaviridae family and belongs to the Hepatovirus genus. To prevent the occurrence of this disease, it is recommended to pay attention to the following points in daily life:

　　1. Develop good hygiene habits and control the entry of diseases through the mouth. Foods should be heated at high temperatures. Generally, heating for one minute at 100℃ can render the hepatitis A virus inactive.

　　2. For foods that are prone to carry pathogenic bacteria, such as snails, shells, crabs, and especially marine and aquatic products like the clam that can accumulate hepatitis A virus, they must be thoroughly cooked and steamed to prevent the bad habits of eating them raw, half-cooked, or directly after pickling.

　　3. Vaccination against hepatitis A can improve the immunity of the population and prevent the occurrence and outbreak of hepatitis A.

　　4. For close contacts, including all exposed individuals when the source of infection is clear (such as food or water), members of schools, hospitals, families, or other units where hepatitis A has been流行, intravenous immunoglobulin injection can be given in a timely manner. The earlier the injection, the better, and it should not be delayed beyond 7-10 days after contact with the infection, as the immune effect can last for 35 days. Medical observation of close contacts should be carried out for 45 days.

　　5. Foodborne infections should check the anti-HAV-IgM of chefs, and after confirmation, they should be isolated and treated.

　　6. In the event of a hepatitis A patient, it is necessary to promptly report to the local disease prevention and control center to take effective measures to isolate the source of infection, cut off the transmission route, protect susceptible populations, control the spread of infectious diseases, and early reporting is of great significance for controlling the epidemic.

　　Hepatitis A virus infection, abbreviated as hepatitis A or HA, is an infectious disease caused by hepatitis A virus (HAV), mainly characterized by inflammatory changes in the liver. Generally, the following examinations are needed for this disease:

　　1. Laboratory examination

　　Blood and urine routine: peripheral blood routine shows a general decrease in white blood cell count or within the normal range, with a mild increase in the ratio of lymphocytes or monocytes. In the early stage of the disease, the concentration of urobilinogen in urine increases, and during jaundice, both bilirubin and urobilinogen in urine increase. Liver function tests, with the detection of serum ALT, AST, and total bilirubin levels, are most useful. Studies have shown that the average peak ALT in patients with hepatitis A can reach 1952 IU/L, and AST can reach 1442 IU/L, with most apparent infectious patients showing an increase in serum total bilirubin levels.

　　2. Hepatitis A virological indicators

　　(1) Anti-HAV IgM can be detected in serum about 1 week after onset. Its appearance is consistent with the time of clinical symptoms and abnormal laboratory indicators, reaching a peak in the second week. Generally, it lasts for 8 weeks, and a few patients can last for more than 6 months. However, some patients may initially test negative and become positive after 2-3 weeks. Therefore, when clinically suspected of hepatitis A with negative anti-HAV IgM, it should be repeated 1-2 times to avoid missed diagnosis. Currently, anti-HAV IgM is a highly specific indicator for early diagnosis of hepatitis A, with the advantages of simplicity and rapidity. Anti-IAVIgG is an indicator of past infection, as it is a protective antibody that can protect the body from re-infection, and can be used for epidemiological investigation to understand susceptible populations.

　　(2) Anti-HAV-IgA antibodies, also known as secretory antibodies, mainly exist in tears, saliva, urine, gastric juice, breast milk, and nasal secretions. The IgA in gastric juice can be excreted into feces, and anti-HAV-IgA can be detected in the fecal extract of patients with hepatitis A. They can be used as an auxiliary diagnosis for hepatitis A. In addition, the detection of HAV in feces and serum hepatitis A ribonucleic acid (HAVRNA) also has diagnostic value, but it requires certain equipment and technology and is not routine examination items. In summary, for suspected cases of hepatitis A with typical symptoms and明显 elevated transaminases, further examination of anti-HAV IgM can help confirm the diagnosis of hepatitis A.

　　Hepatitis A is one of the common liver diseases. This disease is infectious. To help patients recover faster, the following food therapy is recommended for patients with hepatitis A:

　　1, Artemisia capillaris Fresh Mushroom Porridge

　　Ingredients: young Artemisia capillaris leaves 20 grams, fresh mushroom slices 15 grams, glutinous rice 100 grams.

　　Preparation: First, wash and drain the fresh Artemisia capillaris, cut the fresh mushrooms into thin slices, and after the glutinous rice is cooked, put the fresh mushroom slices in the porridge and blanch for a moment, then add the fresh Artemisia capillaris leaves for 5 minutes, and it can be taken warm.

　　2, Rhizoma Cyperi, Poria, and Dioscorea opposita Chicken

　　Ingredients: Rhizoma Cyperi 15 grams, Poria 15 grams, Dioscorea opposita 30 grams, chicken 1.

　　Preparation: Remove the internal organs of the chicken, put Rhizoma Cyperi, Dioscorea opposita, and Poria in the chicken abdomen, steam over water, remove the medicinal residue, and take it.

　　3, Fructus lycii and Dioscorea opposita Porridge

　　Ingredients: fructus lycii 20 grams, Dioscorea opposita 30 grams, glutinous rice 50 grams, a small amount of sugar.

　　Preparation: Put fructus lycii, Dioscorea opposita, and glutinous rice in a pot, add an appropriate amount of water, boil with high heat and then change to low heat for half an hour until the rice is soft, and take it warm.

　　Hepatitis A belongs to the category of 'Liver瘟' and 'Ji Huang' in traditional Chinese medicine. The syndrome is mostly damp-heat and blood stasis in the liver and gallbladder, and the treatment should be based on clearing heat and promoting diuresis, cooling the blood and resolving blood stasis, and eliminating epidemic toxins and jaundice.

　　Traditional Chinese medicine uses Ji Huang Decoction (Cimicifuga rhizoma, Atractylodes macrocephala, Artemisia capillaris, Gentiana scabra, Plantago asiatica, Talcum, Coptis chinensis, Curcuma phaeocaulis, Bupleurum chinense, Prunella vulgaris, Polygonum cuspidatum, Herba epimedii, and Smilax glabra) with modifications. For those with red tongue, thick yellow greasy coating, fever, sweating, and dry stools, add raw rhubarb after decoction; for those with pale and bloated tongue, white greasy coating, aversion to cold, and loose stools, remove Gentiana scabra and add prepared Astragalus membranaceus and prepared Atractylodes macrocephala; for those with abdominal distension, nausea, aversion to oil, and poor appetite, add fried Atractylodes macrocephala, fried枳壳, Lai Fu Zi, and prepared Pinellia ternata. Take 1-2 doses a day, decocted 2-4 times, and taken warm in 3-4 doses. Take for 15-30 days consecutively.

　　In the formula, Cimicifuga rhizoma and Smilax glabra are used to disperse the upper and lower parts, Bupleurum chinense and Curcuma phaeocaulis are used to soothe the liver and benefit the gallbladder, Polygonum cuspidatum and Herba scutellariae are used to eliminate epidemic toxins, Prunella vulgaris is used to cool the blood and resolve blood stasis, Artemisia capillaris, Gentiana scabra, Plantago asiatica, Talcum, and Coptis chinensis are used to clear the liver and benefit the gallbladder, eliminate dampness and jaundice, which is very suitable for the treatment of damp-heat and blood stasis in the liver and gallbladder.