Hepatitis A

Hepatitis A (epidemic hepatitis, infectious jaundice) is an acute inflammatory liver disease caused by a small RNA virus that is transmitted through the fecal-oral route. It is a rather contagious disease that can occur sporadically or there can be epidemic phenomena, especially in conditions of deteriorating sanitary conditions after floods and other natural disasters.

Spread

It appears in all parts of the world, but it occurs endemically, with occasional epidemics, more often in less developed and underdeveloped countries of the world (eg countries of Africa, the Middle and Far East, Central and South America).

Path of transmission

In the transmission of the Hepatitis A virus, the feco-oral route of transmission ("dirty hands" disease) plays a fundamental role. The contact route of transmission is conditioned by the presence of fresh fecal contamination on the cheekbones of the fingers, so transmission is much easier in those people who do not wash their hands with soap. Children are the most susceptible to this infection, although the disease is usually milder and lasts less. The field of the virus depends on the sanitary condition of the environment, hygiene habits and the size of groups in close contact (eg kindergartens, schools, families, etc.). In contrast to countries with lower hygiene standards, hepatitis A in developed countries occurs later in life due to the improvement of socioeconomic living conditions. The disease can also be transmitted by contaminated water. Then hepatitis usually occurs in the form of mass epidemics of an explosive character, and all ages are affected. The hepatitis A virus can also be spread through contaminated food. It is usually about foods that do not undergo heat treatment or that is insufficient (eg raw or insufficiently heat-treated shells that come from contaminated water), that is, pollution occurs after additional manipulations (therefore it is important to control people who work with food). There is little evidence of a risk of HAB transmission through heterosexual contact, while the frequency of anti-HAB is high in homosexual men. Pareneral transmission of HAB as homosexual men frequency of anti- HAB high. Parenteral transmission of HAB via blood is possible, but extremely rare. Humans are the only reservoir of the hepatitis A virus (the patient can infect other people in the incubation phase and in the acute phase of the disease). Infected people can transmit the virus to other people for two weeks before symptoms appear. Well, up to a week after the appearance of the yolk (all together about three weeks).

Clinical picture

Incubation ie. the time that passes from the entry of the virus into the body until the appearance of the first symptoms of the disease lasts from 2 to 4 weeks. Symptoms of the disease include fever, muscle and joint pain, nausea and vomiting, and sometimes diarrhea. When the temperature drops, the skin and sclera become yellow, the urine dark and the stool lighter. This is a sign that the liver is enlarged. After 1 to 2 weeks, the symptoms of the disease disappear, but full recovery takes longer (4 to 6 weeks). The disease usually passes spontaneously and never turns into a chronic form. However, HAB can cause prolonged cholestasis (bile stasis) accompanied by elevated levels of alkaline phosphatase and total birubin that may persist for several months or, more rarely, take a chronic relapsing course (this is considered a consequence of incomplete resolution of HAB). The described condition is usually resolved within a year at the latest. Hab can also be a trigger for a form of autoimmune hepatitis that is mistaken for "chronic" hepatitis. There is a small number of patients in whom the disease suddenly appears, and severe so-called the fulminant form can damage the liver. It has been observed that fulminant hepatitis A, although rare, occurs with increasing frequency in intravenous drug addicts. The signs of the disease depend on the condition of the patient, but also on the age at which the infection occurred. In childhood, especially in the first years of life, the disease is mild and often goes unnoticed. However, infection at a later age can take on a more severe form of the disease.

Laboratory tests

Laboratory findings show elevated values ​​of liver enzymes (AST, ALT), which is a sign of liver cell damage, as well as elevated bilirubin. During an acute infection, the patient's immune system creates IgM anti-HAV antibodies that remain in the blood for the next 6 to 12 months from the appearance of the first symptoms of the disease. The presence of IgM anti_HAV in the serum is an indicator of chronic hepatitis A or immunity acquired by vaccination against hepatitis A. The virus can be isolated from the stool of the patient, but it is not done routinely.

Treatment

The treatment is symptomatic and consists in lowering the body temperature (with antipyretics), maintaining electrolyte balance, rest and diet. In the case of a more severe form of the disease, the person is placed in an intensive care unit. The disease passes spontaneously, and the transition to the chronic form of the disease has not been recorded.

Prevention

The basic prevention of hepatitis A is the same as for other intestinal diseases, i.e. creation of conditions for regular implementation of personal and environmental hygiene measures (hand washing, proper disposal of waste materials, provision of healthy water and food) the disease can also be prevented by vaccination which is recommended for: travelers to endemic areas, medical staff, staff and residents in centers full-day care, people who participate in the food production process, people who work in communal companies (garbage removal and sewage-related jobs), people with some chronic liver diseases. Also, vaccination against hepatitis A is recommended for homosexuals as well as intravenous drug addicts. Hepatitis A vaccination is recommended for people who live in a household with an infected person as well as people who are in sexual contact with an infected person - post-exposure prophylaxis two weeks after exposure to the infection. Vaccination consists of two doses of inactivated vaccine, with the second dose following 6 to 12 months after the first dose. Today, there is also a combined vaccination that protects against hepatitis A and B. It is given in three doses (the second dose one month after the first, and the third dose five months after the second). The protection thus obtained is long-lasting.