Viral hepatitis A

Viral hepatitis A (infectious hepatitis, epidemic hepatitis, Botkin's disease) is an acute human viral disease with a fecal-oral mechanism of transmission of the pathogen.

It is characterized by liver inflammation, cyclic benign course, may be accompanied by jaundice.

[1], [2], [3], [4],

Epidemiology

The main role in the development and activation of the epidemiological process is played by a person infected with the HAV virus. Especially dangerous is the subclinical, jaundiced variant of the disease, when the infection passes through the stage of incubation and releases a virus that is excreted with feces. The process of isolating the causative agent of hepatitis A into the external environment continues to the initial clinical manifestations of the disease and lasts up to four weeks. The first two weeks from the onset of the disease are considered the most dangerous in terms of contagiousness. The virus during this period can be found not only in feces, but also in urine, in sperm, in vaginal discharge and menstrual blood.

The epidemiology of hepatitis A is characterized by a unified mechanism of transmission of infection - fecal-oral, which is carried out through food, water by household or by contact. Also for hepatitis A epidemiological outbreaks of mass infections are typical, most often in institutions where a group of people simultaneously receives infected food or contaminated water (kindergartens, school canteens and so on). Some experts claim that there is also a vertical, parenteral route of transmission of hepatitis A. Indeed, in practice, there have been isolated cases of infection of the child during childbirth by the mother - carrier of the virus, as well as infection with HAV during injection manipulation, but these phenomena can not be considered typical.

Hepatitis A is attributed to childhood diseases by age, since about 80% of cases are children under 14 years old, the adult population accounts for only 15-20% of all reported cases of HAV.

By geographical parameters, the epidemiology of hepatitis A is as follows (WHO statistics): 

• A high epidemiological level of HAV spread is noted in all countries classified as developing. Poor sanitation and hygiene conditions, insufficient epidemiological control leads to the fact that more than 90% of children become infected with hepatitis A at an early age, up to 10 years. Mass outbreaks of the disease are recorded quite rarely, this is due to the fact that most adults have already had HAV and have been resistant to the virus. 
• The average epidemiological level of HAV infection is recorded in countries classified as developing in a transition economy. Significant improvement in sanitary and hygienic standards, epidemiological control leads to the fact that infants are ill with hepatitis A rarely. However, this is also a paradoxical cause of HAV disease in an adult population that is not immune and has a high sensitivity to the virus. In such countries, there are periodic outbreaks of mass infection with hepatitis A. 
• The low level of epidemiological situation associated with HAV is noted in all developed countries with a stable socio-economic situation. Cases of infection are recorded mainly in people at risk - people without a specific place of residence, leading an antisocial way of life. Also, hepatitis A and those who make tourist trips to countries with a high epidemiological level are at risk of contracting.

According to the latest WHO statistics, more than 1.4 million people worldwide get Hepatitis A every year.

The disease has long been labeled as a dirty hand disease, so the higher the overall sanitary and hygienic culture of the country's population, the fewer cases of infection with the HAV virus are recorded in it.

[5], [6], [7], [8], [9], [10], [11], [12]

Causes of the hepatitis A

The cause of hepatitis A is the penetration of the virus into the liver cells, in most cases through contaminated food. The second way of infection is water contaminated with sewage (water). Thus, food and raw water, even those that are washed with raw vegetables or fruits, are the main reservoir of infection with hepatitis A. Also, the virus can spread by contact, for example, in people infected with HAV. To provoke infection can such situations: 

• The use of food prepared by a person infected with hepatitis A (especially if it does not handle hands after going to the toilet).
• The use of food (vegetables, fruits), washed with untreated, virus-infected water.
• The use of dishes prepared by a person who has not washed his hands after changing diapers, a shroud from a child infected with hepatitis A.
• Eating from raw seafood (oysters, mussels, other mollusks), whose habitat is located in the waters infected by the virus, including in wastewater.
• Homosexual (anal) sexual contact with a person infected with the virus.

Hepatitis HAV virus perfectly feels in an aqueous, liquid environment and is not afraid of acidity. After ingestion of contaminated food or water, the HAV pathogen enters the gastrointestinal tract, which safely passes and is absorbed into the blood. Thus, hepatitis A enters the liver and begins its pathological effect on hepatocytes. Virions quickly reproduce in the cells of the organ, exit from them and are discharged through the bile ducts into the intestine. Inflammation of the liver and its lesions is caused by an active immune response, when T-lymphocytes come into conflict with the identified damaged, and therefore subject to destruction, hepatocytes. The level of bilirubin found in the liver cells increases, it penetrates the bloodstream, coloring the skin in a characteristic for hepatitis icteric shade. Infected cells die, provoking an inflammatory process, a violation of liver function and proper hepatitis.

[13], [14], [15], [16], [17], [18]

Pathogenesis

One of the most common infectious diseases in the world is hepatitis A. Until the end of the XIX century, the disease was called catarrhal jaundice and associated it with the inflammatory process in the biliary tract. The infectious etiology of hepatitis A has been identified by the great clinician S.P. Botkin, since this concept is leading in the practice of diagnosis and treatment of hepatitis, and to specify and identify the causative agent was only in 1973. HAV (hepatitis A) virus belongs to a group of small picornaviruses lacking a lipoprotein layer, with a single-stranded RNA structure. The causative agent is very resistant to various factors and can persist in the environment for several months at a comfortable room temperature for it. Even in the frozen form, the virus does not lose its viability for 1.5-2 years, and its acid-resistant shell helps to overcome the protective secretory secretions of the stomach and penetrate the liver. A person who has recovered from hepatitis A, retains a stable immunity to the virus for life.

You can inactivate the infection by boiling or steaming, in addition. The use of disinfectants - chloramine, formalin, as well as ultraviolet irradiation, makes it possible to neutralize the hepatitis A virus.

[19], [20], [21], [22], [23], [24]

Symptoms of the hepatitis A

Symptoms of hepatitis A are associated with the course of the disease. HAV can have different types and proceed in three forms, among which the following are noted: 

Types: 

1. A typical hepatitis A, which develops classically with all the characteristic symptoms, including jaundice.
2. Hepatitis A is atypical, which is characterized by an icteric stage and a chronic course.

Forms: 

1. The most common is an easy form.
2. A third of patients (28-30%) are diagnosed with a moderate form.
3. The least severe form of hepatitis A (no more than 3% of cases.

Symptoms of hepatitis A can also vary and depend on the course of the disease: 

1. Cyclic, sharp.
2. Recurrent, prolonged, protracted.
3. Chronic, persistent.
4. Aggressive, accompanied by cholestatic symptoms (syndrome).

In the clinical and biochemical sense, HAV manifestations are divided into the following syndromes: 

1. Cytolysis, characterized by a sharp increase in direct bilirubin and a sharp jump in the level of AlAT (alanine aminotransferase) in the patient's blood.
2. Cholestasis, which is also characterized by an increase in the level of bilirubin in the blood, as well as an increase in the amount of alkaline phosphatase and cholesterol.
3. Mesenchymal-inflammatory syndrome, which is accompanied by high ESR, the level of gamma globulin and a decrease in the level of the mercury index in the blood.
4. Severe hepatoprimal syndrome, when the blood level of albumin and fibrinogen decreases sharply and hepatic insufficiency (encephalopathy) develops.

From the onset of infection to the first clinical symptoms can take 2-4 weeks, the symptoms of hepatitis A can be as follows: 

Hepatitis A in mild form:

• Pre-jaundiced period (3-7 days):
  • A slight increase in body temperature, from 37.2 to 37.7 degrees in the first 2-3 days of illness.
  • Periodic feeling of nausea, vomiting is possible.
  • Superficial restless sleep.
  • Feeling of aching pain in the liver, in the right hypochondrium.
  • Dyspepsia, flatulence.
  • Staining urine and feces in atypical color - urine darkens, feces depigmented.
• Jaundice period (from 7 to 10 days):
  • Gradual staining of the skin, eye sclera yellowish tint. Jaundice usually begins with the whites of the eyes and spreads down the body.
  • Improvement of the condition, stihanie pain in the right hypochondrium.
• Restorative stage:
  • Normalization of liver function, restoration of its normal size.
  • Residual effects of mild fatigue after physical exertion.

Symptoms of hepatitis A in a moderate form: 

• Poor appetite.
• Subfebrile body temperature.
• Reducing the amount of urine.
• Increased liver size.
• Severe pain in the liver.
• Darkening of urine and discoloration of feces.
• Clearly expressed jaundice, lasting until the 21st day.
• Longer than in mild form, the recovery period is up to 2 months.

Hepatitis A in severe form (rarely diagnosed): 

• A sharp onset of the disease and a rapid increase in symptoms.
• High body temperature - up to 39 degrees.
• Lack of appetite, food causes vomiting.
• When jaundice appears, the symptoms do not subside, but rather become more pronounced.
• All signs of a general intoxication of an organism are shown - headaches, dizziness.
• Pain in the muscles, joints.
• Hemorrhages under the skin (hemorrhagic), nasal bleeding.
• Rash.
• Lack of urge to urinate.
• Hepatomegaly, splenomegaly.

[25], [26], [27],

Diagnostics of the hepatitis A

Diagnostic measures are divided into two types: 

• Specific - detection of the virus, its virions and immune antibodies.
• Nonspecific - the definition of the liver and the level of damage to hepatocytes.

Diagnosis of hepatitis A includes the collection of anamnesis, visual examination of the patient, palpation of the right hypochondrium. The appearance of the patient - the color of the tongue, the eye proteins, the skin, the level of body temperature is assessed.

As laboratory diagnostic methods, immunoenzymatic and biochemical blood analysis is widely used. As a nonspecific method, the parameters of protein metabolism, enzyme activity and albumin, bilirubin levels are used.

The list of laboratory studies that detect hepatitis A and the inflammatory process in the liver: 

• Immunofermentogram for the determination of antibodies to the virus (HAV-IgM, IgA), which can be determined only in the acute period of the disease.
• Biochemical studies to detect the level of enzymes of cytolysis of the liver - AsAt (asparatransferase), ALAT (alaminotransferase), gamma GT or gamma-glutamyltransferase, alkaline phosphatase, LDH (milk dehydrogenase).
• Determination of the level of direct and indirect bilirubin.
• An analysis determining the prothrombin index, which shows the rate of blood clotting.
• General blood analysis.
• Coagulogram.
• General urine analysis.

Diagnosis of hepatitis A can be difficult in asymptomatic disease (jaundice form). Markers that help to identify a virus are IgM antibodies that can be detected most often only in the acute course of the disease, IgG antibodies are most often detected, which is an indicator of the reconstitution, that is, the restoration of the liver function after infection. Also, in the initial period of the disease (prodromal), it is important to differentiate hepatitis and enterovirus infection, ARI, since these nosological forms also manifest themselves with fever and signs of dyspepsia. However, the influenza virus is characterized by neurotoxic and catarrhal symptoms, and hepatitis is characterized by hepatomegaly and changes in liver function.

[28], [29], [30], [31], [32], [33], [34]

Treatment of the hepatitis A

Therapeutic strategy for hepatitis A is most often limited to a special gentle diet, involving the restriction of fats and the addition of carbohydrates. As a rule, this is the appointment of diet No. 5 for Pevzner. Also, bed rest, reduced physical activity and exercise, and copious drinking are helpful. For relief of symptoms, treatment of hepatitis A involves the use of choleretic preparations, infusions, hepatoprotectors, antispasmodics. The strategy and tactical actions of HAV therapy can be systematized and presented in this way:

Basic Activities	Bed rest sparing
	Diet, specific therapeutic nutrition (table number 5). In the acute period of the disease and with the moderate form of hepatitis, diet No. 5a
Detoxification measures for cleaning the gastrointestinal tract and liver	The purpose of enterosorbents is polyphepan, enterosgel, lignosorb
Detoxification measures for blood purification through the urinary system, kidneys	Abundant alkaline drink (mineral water, freshly squeezed vegetable and non-acidic fruit juices) The use of drugs - diuretics, as well as glucocorticosteroids
Detoxification measures for the removal of toxins through the skin	Heat, regular baths, showers, skin care for sweating and microcirculation
Neutralization of hypoxia of organ tissues, lipid peroxidation	The purpose of antioxidants - vitamins E, A, C, PP, Essenitsale, Riboxin
In severe disease, extracorporeal detox methods	Plasmapheresis, plasmosorption, hemosorption, hemoxygenation
Measures to help correct liver protein function and its regeneration	Amino acids, albumin, plasma intravenously Vitamin-mineral therapy (oral, injection) Preparations containing potassium
Neutralization of necrosis and fibrosis of liver tissue	The purpose of inhibitors of proteinases - gordoks, contrikal, hormonal drugs
Coping with cholestasis	The purpose of ursodeoxycholic acid and other types of acids of this group, its preparations containing - Ursofalk, henofalk, taurofalk. Application of enterosorbents Tyubazh or the prescription of cholagogue means
Treatment of hepatitis A for the purpose of correction of hemostasis	Assignments in accordance with coagulogram information
Correction of the functions of the gastrointestinal tract, biliary system	Assigning probiotics, prebiotics, enzymes

Prevention

Preventive measures against many viral diseases are compliance with personal hygiene. If the influenza virus is vulnerable in terms of infection with the nose and mouth, through which the pathogen can enter the body, the prevention of hepatitis A is a cleanly washed hand, it's no accident that HAV was called "sickness of dirty hands". Just as in cases of other intestinal diseases, preventive measures include the processing of food, the purification or boiling of water and the implementation of the simplest rules of sanitary and hygienic norms. In this sense, not only personal preventive efforts are effective, but also systematic verification, treatment of drinking water, assessment of the cleanliness and safety of food by sanitary and epidemiological services at the level of state programs.

In addition, the prevention of hepatitis A is the prophylactic examination of the population and monitoring of persons who are in contact with infected HAV patients. Monitoring of the condition of the contact persons is carried out within 30-35 days with mandatory weekly fixation of clinical symptoms, testing of ALT activity (biochemical blood test), detection of antibodies to the virus (immunofermentogram). If contact persons are pregnant women and children up to 12-14 years of age, the introduction of a prophylactic dose of immunoglobulin is indicated. The most effective method of prevention throughout the world is the timely vaccination against hepatitis A, especially in areas with an increased epidemiological level of infection.

Other recommendations for prevention do not present difficulties in implementation:

• Wash hands thoroughly, preferably with soap after each visit to a personal or public toilet.
• Carefully wash raw vegetables, fruits, preferably boiled water, in extreme cases - flowing for a long time.
• If possible, it is desirable to pour vegetables, fruits with boiling water, especially if they are intended for children.
• Use raw water only from clean sources checked by the relevant services. If the source of water is in doubt, the water should be boiled for 3-5 minutes.
• Wash hands every time before preparing food, as well as before eating.
• Wash hands after visiting public, public places, after traveling in transport.
• To teach children to observe the rules of personal hygiene.
• Do not try fruits, berries in spontaneous markets.
• Do not eat foods of dubious appearance.
• Regularly check hygienic certificates and shelf life of products purchased in stores, supermarkets.
• Do not use cutlery, personal hygiene items of persons infected with hepatitis.

Vaccination against hepatitis A

Today, vaccination against hepatitis A is considered the basis of preventive measures that help stop the infection of the population with the HAV virus. A vaccine is a detoxified virus that is characterized by high immunogenicity. Vaccination is carried out twice with an interval of six months and a year. Immune antibodies to the introduced vaccine appear in the body after 1.5-2 weeks, the immune defense after vaccination is maintained for a minimum of six years, a maximum of ten years.

It is believed that vaccination against hepatitis A is effective from an early age, however, most often it is carried out from the age of three. Vaccinations are also shown to adults who are not sick with HAV, persons belonging to the groups of potential infection (risk groups).

Categories of people who are at risk of contracting hepatitis A:

• Medical personnel of in-patient medical institutions who have contact with patient groups, as well as staff of infectious hospitals.
• All without exception, employees of children's school and preschool institutions.
• Employees working in public catering establishments, as well as persons working in the water supply system of settlements.
• People who have a history of liver disease.
• People who plan to travel to countries with a high epidemiological level of infection with hepatitis.
• Persons in contact with patients / carriers of hepatitis A (family members, relatives).
• Persons entering into sexual contact with infected partners.

Also, vaccination against hepatitis A is desired and those who inject drugs, prefers homosexual sex.

To date, the pharmaceutical industry has begun to produce vaccines that can be used for children aged one year and older.

[35]

Forecast

Among all types of hepatitis HAV is considered relatively safe for the liver, indeed, the disease can be resolved on its own 5-6 weeks after the onset of infection, especially in acute forms of hepatitis. In this sense, the prognosis of hepatitis A is favorable, and severe complications are considered an exception rather than a typical consequence. Transformation HAVv fulminant (rapid) form, ending with the death of the patient, is recorded very rarely.

Such cases are diagnosed in patients who have a history of hepatitis B and C. Lethal outcome in such patients is due to general intoxication of the body, acute liver failure and extensive necrosis of liver tissue. The risk of an unfavorable outcome of the disease is low and is:

• Children under 10 years old - 0.1%.
• Children from 10 to 15 years - 0.3%.
• Adults under 40 years old - 0.3%.
• Individuals over 40 years of age - 2,1-2,2%.

In addition, the prognosis of hepatitis A depends on the regional epidemiological specificity, the state of the immune system and the functions of the human liver at the time of infection with the virus. Nevertheless, HAV in most cases ends in complete recovery.

[36], [37], [38], [39],