Hepatitis A Hepatitis A (abbreviated as HAV) is caused by the hepatitis A virus. This virus has only one serotype. It is primarily transmitted through the fecal-oral route and can occur year-round, with a higher incidence in autumn. It is commonly associated with contaminated food. The disease is more prevalent in preschool-aged children, and outbreaks are prone to occur in collective childcare settings.

bubble_chart Clinical Manifestations

1. Jaundice type: The onset is relatively acute, often with fever and lack of strength at the beginning. Gastrointestinal symptoms are more prominent, such as nausea, loss of appetite, aversion to greasy food, vomiting, abdominal distension and fullness, loose stools, and upper abdominal pain, followed by jaundice. The urine color resembles strong tea and "sticks to the basin." The skin and sclera show yellow staining, and the stool turns grayish-white. The liver is enlarged with tenderness and percussion pain. Generally, jaundice lasts about 2 weeks. The entire course of the disease lasts approximately 1 to 4 months.
2. Non-jaundice type: The symptoms and signs are similar to those of jaundice-type hepatitis, but most cases have milder symptoms, and jaundice does not appear throughout the course of the disease.

bubble_chart Auxiliary Examination

1. The total white blood cell count and neutrophils in the blood picture are normal or slightly low, and abnormal lymphocytes (not exceeding 10%) may be observed.
2. Liver function: Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increase during the acute phase and decrease as the condition improves. A persistently abnormal ratio of serum total protein to albumin (A)/globulin (G) suggests chronic liver function impairment. 3. Serum bilirubin: In jaundice cases, both direct and indirect bilirubin levels are elevated. 4. Urine bilirubin: In jaundice cases, urine bilirubin is positive when serum bilirubin exceeds 3 mg/dl. Urobilinogen may increase before jaundice appears. 5. Serological tests: (1) A positive anti-HA IgM antibody indicates recent or current hepatitis A infection. This antibody appears shortly after infection and typically disappears within about 2-3 months. A single positive serum test is sufficient for diagnosis. (2) If anti-HA IgM antibody is negative but anti-hepatitis A virus IgG antibody (anti-HA IgG) is positive, it indicates a past HAV infection. IgG antibodies can persist in the blood for many years.
3. Etiological examination: Hepatitis A virus particles can be detected in feces 2-3 weeks after the incubation period and within 1 week of symptom onset, or the presence of the virus can be confirmed by measuring the HIV titer in feces.

bubble_chart Treatment Measures

﹝Treatment﹞

There is no specific treatment, mainly symptomatic and supportive therapy. (1) Rest During the acute phase, bed rest for 1 month and isolation for 40 days are recommended. Hospitalization is advised if conditions permit. During the convalescence stage, gradually increase activity and avoid overexertion. (2) Diet In the acute phase, provide a light semi-liquid diet. For those with poor appetite and vomiting, intravenous infusion of 10% glucose with vitamin C, glucurolactone, and energy mixture can be administered, or intravenous injection of 50% glucose + vitamin C. After appetite recovers, consume a high-protein, high-vitamin, low-fat diet, such as milk, eggs, fish, lean meat, soy products, vegetables, fruits, etc., with a moderate amount of sugar (about 50g per day). Avoid excessive food intake to prevent fatty liver. (3) Medications

1. Provide multiple vitamins (vitamin B complex, C, E, A, D, etc.; for severe jaundice or bleeding tendency, vitamin K can be given). Infants and young children should especially ensure adequate intake of vitamins A and D. 2. Liver-protecting and enzyme-lowering drugs: glucurolactone, liver extract, compound choline, bifendate, stringy stonecrop herb infusion granule, water-ground thistle extract, coenzyme A, and adenosine triphosphate (ATP), etc. Avoid drugs that may harm liver function, such as phenobarbital and macrolide antibiotics. 3. Immunomodulatory drugs (1) Adrenal corticosteroids: Generally not used, but in cases of acute severe hepatitis with rapidly rising serum bilirubin, short-term early treatment with prednisone 1mg/(kg·d) for 7–10 days may improve symptoms. (2) Immunostimulants: Thymosin 10–15mg per dose, once daily, added to 10% glucose for intravenous drip; transfer factor and immune RNA, one vial per dose, once weekly, subcutaneously injected in the axillary or groin area; levamisole 2–3mg/kg daily, used for 2 consecutive days per week, with a course of 3 months, etc., can be used for chronic hepatitis with low cellular immunity

bubble_chart Prevention

(1) Strictly manage the source of pestilence: Children in the acute phase must be isolated for at least 30 days from the onset of illness, and those in childcare institutions should be isolated for 40 days. (2) Cut off the transmission route of pestilence: Strictly implement the management system for intestinal pestilence diseases, maintain personal hygiene, especially dietary hygiene. Disinfect patients' excreta with bleaching powder, and pay attention to the sterilization of syringes. (3) Passive immunity: Administer placental globulin or gamma globulin to close contacts within 10 days of exposure to the pestilence source. (4) Active immunity: Hepatitis A vaccine has been used in major cities in China, but it is expensive and has not yet been included in the planned immunization program. **Hepatitis B** Hepatitis B (abbreviated as HBV) is caused by the hepatitis B virus (HBV). This virus belongs to the hepadnavirus family and has surface antigen (HBsAg), core antigen (HBcAg), and e antigen (HBeAg). It is primarily transmitted through close contact, injections, blood transfusions (or blood products), and mother-to-child transmission. In China, HBsAg-positive carriers account for about 10% of the total population. Infection leads to the production of corresponding antibodies. Infants and children infected are more likely to become long-term HBsAg carriers or develop chronic hepatitis. Over the past decade, the use of live hepatitis B vaccines and high-titer hepatitis B immune globulin has provided effective protection for infants from birth.

bubble_chart Differentiation

(1) Toxic hepatitis caused by severe infection may present with jaundice and elevated serum alanine aminotransferase levels. The hepatitis improves as the primary infection is controlled. (2) Infectious mononucleosis may present with hepatomegaly and liver dysfunction, resembling viral hepatitis. The disease is primarily characterized by fever, lymphadenopathy, and pharyngitis. Blood tests may show atypical lymphocytes exceeding 10%, a positive heterophil agglutination test, and positive anti-$% viral antibodies. (3) Hemolytic jaundice presents with progressive anemia, often accompanied by splenomegaly and increased reticulocytes, with predominantly elevated indirect bilirubin.