What Are the Common Causes of Hepatitis A?

In 1973, Feinslone first discovered Hepatitis A virus (HAV) in the stool of patients with acute phase using immunoelectron microscopy. Hepatitis A virus is a hepadnavirus belonging to the Picornaviridae family. After HAV infection in humans, most of them show subclinical or recessive infection, and only a few people show acute hepatitis A. It usually recovers completely, does not turn into chronic hepatitis, and has no chronic carriers.

The diagnosis of hepatitis A is not only based on clinical symptoms, signs, various laboratory tests, and epidemiological data.

1. Characteristics of Hepatitis A virus: It belongs to picornavirus and contains a single-stranded positive-strand RNA genome. There is only one serotype and one antigen-antibody system. Therefore, its detection antibodies are used in countries around the world. HAV is heat-resistant and is only partially inactivated at 60 ° C for 1 hour. Hepatitis A is a fecal and mouth infectious disease. It is different from blood-borne infections such as hepatitis B caused by syringes, perinatal placenta, etc., or hepatitis C caused by injection, blood transfusion, etc. No vertical transmission of hepatitis A has been found in mothers and infants. HAV mainly causes hepatitis A epidemic with water or food. It can be stored in aquatic shellfish, and raw food and semi-raw food can cause hepatitis A ^[5]

1. Isolating patients: Pay attention to disinfecting their feces. The isolation period for patients should be no less than 30 days. Patients in child care institutions should be isolated for 40 days. In endemic areas, patients and close contacts are usually observed for 4 to 6 weeks. Patients treated in home isolation must strictly abide by the personal hygiene system, and the patients used must be carefully disinfected ^[2] .

2. Cut off transmission channels: focus on improving sanitation measures, such as water protection, drinking water disinfection, food hygiene, food disinfection, strengthening personal hygiene, and fecal management ^[2]

3 Protect vulnerable populations ^[2] .

(1) Active immunization: During the hepatitis A epidemic, susceptible populations (infants, young children, children, and serum anti-HAV IgG negative) can be vaccinated with a live attenuated hepatitis A vaccine ^[2] .

(2) Passive immunity: Contacts of patients with hepatitis A can be vaccinated with human serum or placental globulin to prevent the disease ^[2] .