What is Viral Hepatitis E?
Viral hepatitis E is a viral infection from the conditional group of fecal-oral hepatitis, characterized by liver damage, acute cyclic course and severe manifestations in pregnant women.
Viral hepatitis E was isolated from the group of “neither A nor B” hepatitis on the basis of marker diagnostics, evidence of the fecal-oral mechanism and predominantly water transmission, obtained by retrospective analysis (1980) of a major water outbreak in India, observed in 1955. Late M .WITH. Balayan et al. (1982) identified virus-like particles in the feces of a patient with viral hepatitis E and confirmed the independence of this nosological form in the experience of self-infection.
Causes of Viral Hepatitis E
The causative agent of viral hepatitis E is an RNA genomic virus, conditionally included in the genus Calicivirus, although in genetic terms it has significant differences. Virions are round, devoid of supercapsid. In general, viral hepatitis E is less resistant than viral hepatitis A. It is well preserved at temperatures of –20 ° C and lower. It is quickly destroyed by freezing and thawing, under the action of chlorine-containing or iodine-containing disinfectants.
The reservoir and source of infection is a person, patient or carrier. The period of contagiousness of the source is not precisely established, it is probably similar to that of viral hepatitis A. Virus is detected in feces in the early stages of the disease in 15% of cases with mild and moderate forms; in severe cases it is found in almost 50% of patients. Proven pathogenicity of viral hepatitis E for chimpanzees, pigs and other animals.
The transmission mechanism is fecal-oral, the transmission route is predominantly aqueous. There is evidence of the spread of the pathogen and contact-household way. They suggest the possibility of infection with viral hepatitis E by eating raw shellfish. Low foci, the occurrence of mass diseases associated with rainy seasons and high standing of the groundwater level are evidence of the benefit of water as the main factor of transmission of infection.
The natural susceptibility of people is high, especially for women in the third trimester of pregnancy. The relatively rare defeat of children is explained by the predominance of erased subclinical forms over manifest ones, which makes their registration difficult. There are reasonable grounds for believing that after the illness you have experienced, intense immunity is formed, which persists, apparently, throughout the entire life of the patient.
Major epidemiological signs. Viral hepatitis E is widespread in countries with a tropical and subtropical climate, as well as in the Central Asian region. Viral hepatitis E is endemic in areas with extremely poor water supply of the population, characterized by poor quality of water, which is epidemically dangerous, with its severe deficit (risk area). It is believed that about 1 million people get sick with viral hepatitis E annually, and in Asian countries it accounts for more than half of all cases of acute hepatitis. Large water outbreaks (with the number of cases of 15–20 thousand) occurred in India, Burma, Algeria, Nepal, the republics of Central Asia of the former USSR (Turkmenistan, Tajikistan, Uzbekistan, Kyrgyzstan). Since there is no separate registration of viral hepatitis E, it is very difficult to determine the true incidence rates and exact nozareal. Persistent foci of viral hepatitis E exist in the Central Asian region of the former USSR, mainly in lowland and plateau regions. Along with large outbreaks, sporadic diseases are also recorded. Predominantly, the waterway of infection determines a number of epidemiological features of viral hepatitis E: the explosive nature of the incidence, the peculiar age structure of the diseased with predominantly affected persons 15–19 years old, insignificant foci in families, the presence of recurring incidence in endemic areas with an interval of 7–8 years, sharply pronounced territorial irregularity in the prevalence of morbidity, seasonal increase in morbidity in the summer-autumn months.
Pathogenesis During Viral Hepatitis E
The pathogenesis of viral hepatitis E is not fully understood. Infection occurs by drinking contaminated water or food. The virus apparently selectively affects hepatocytes, which leads to impaired liver function and the development of intoxication. In viral hepatitis E, severe forms of the disease are encountered much more frequently than in viral hepatitis E, in some cases leading to death.
Symptoms of Viral Hepatitis E
Symptoms of viral hepatitis E resemble the course of viral hepatitis A.
The incubation period is 10-60 days, more often – 30-40 days. The disease usually begins gradually. The preicteric period lasts from 1 to 9 days, more often 3-4 days. At this time, weakness, malaise, loss of appetite are recorded, in a third of patients – nausea, vomiting. Most patients have pain in the epigastrium and right hypochondrium, and they sometimes reach significant intensity, and in some cases are the first symptom of the disease. Increase in body temperature is quite rare, usually not more than 38 ° C. Joint pain and urticarial rash are not characteristic. The icteric period in uncomplicated cases lasts 1-3 weeks, characterized by the appearance of dark urine, acholic feces, jaundice of the skin and sclera (sometimes significant), an increase in the liver (in most patients it protrudes from the costal arch by 3-6 cm), hyperbilirubinemia , increased transaminase activity. With the appearance of jaundice, in contrast to viral hepatitis A, the symptoms of intoxication do not disappear. Patients still complain of weakness, poor appetite, pain in the epigastrium and right hypochondrium, may be subfebrile, itchy skin. The recovery period lasts 1-2 months, there is a gradual normalization of clinical and biochemical parameters. In some cases, perhaps a protracted course of the disease. A characteristic feature of severely sick forms of viral hepatitis E is hemoglobinuria as a result of hemolysis of red blood cells with the development of acute renal failure and hemorrhagic syndrome. Hemoglobinuria is observed in 80% of patients with severe forms of viral hepatitis E and in almost all patients with acute hepatic encephalopathy. Hemorrhagic syndrome is manifested by gastrointestinal, uterine and other bleeding, and quite significant. There is a close correlation between the severity of the disease and the state of the plasma link of hemostasis. It was noted that a sharp decrease in the number of plasma coagulation factors, as well as protease inhibitors, foreshadows deterioration and the development of acute hepatic encephalopathy, ahead of clinical symptoms for 1-2 days, which is of great prognostic value.
In most cases, viral hepatitis E occurs in mild and moderate forms and ends with recovery. However, an important feature is that in some patients, especially adults, viral hepatitis E can occur in severe and fulminant forms with the development of acute hepatic encephalopathy and end in death. The overall mortality from viral hepatitis E during outbreaks is 1-5%, and among pregnant women – 10-20%, especially in the second half of pregnancy. Selective high mortality of pregnant women is considered a kind of diagnostic label for epidemics of viral hepatitis E. The clinical features of fulminant variants of viral hepatitis E in pregnant women are: late pregnancy (not earlier than 24 weeks); a sharp deterioration on the eve of childbirth (miscarriage) or immediately after them: the rapid development of acute hepatic encephalopathy with precomatose changes during the first two weeks of the disease and the transition to deep hepatic coma over the next 1-2 days; pronounced hemorrhagic syndrome with increased bleeding during childbirth; frequent antenatal fetal death; development of hepatic-renal syndrome.
Diagnosis of Viral Hepatitis E
The basis of laboratory diagnostics of viral hepatitis E is the detection of antigens of viral hepatitis E using PCR and the detection of IgM and IgG to antigens of viral hepatitis E.
Differential diagnosis of viral hepatitis E is difficult due to the fact that the clinical course of hepatitis E in its main manifestations is similar to other viral hepatitis. In the differential diagnosis should take into account anamnestic information about the patient’s stay in areas unsuccessful for the disease (tropics and subtropics, Central Asian republics of the CIS). Hepatitis E is more common in young people. If you suspect hepatitis E in pregnant women, a mandatory marker diagnosis is necessary to confirm the diagnosis, since their disease is most difficult with a large number of deaths.
Treatment of Viral Hepatitis E
Treatment of viral hepatitis E in uncomplicated cases is similar to that of viral hepatitis A.
Treatment of patients with mild and moderate forms of viral hepatitis E is carried out according to the standard scheme – diet, treatment and protection regime, if necessary – detoxification agents; corticosteroid administration is not indicated. Treatment of severe forms of viral hepatitis E is organized in intensive care units.
Detoxification therapy includes intravenous administration of hemodez, 5-10% glucose solution, isotonic sodium chloride solution in combination with potassium and magnesium preparations. Protease inhibitors are prescribed. For the prevention and treatment of hemorrhagic syndrome, trental, dicine, transfusion of fresh frozen plasma, platelet mass, etc. are used.
The principles of obstetric tactics for viral hepatitis E are as follows:
- regular observation;
- intensive therapy of the underlying disease in conditions of maximum physical and mental rest;
- prevention and treatment of hemorrhagic syndrome;
- timely detection of precursors of threatened abortion (lower back pain, lower abdomen, increased uterine tone, the appearance of bleeding from the genital tract);
- treatment of threatened abortion.
When abortions and childbirth begin, it is necessary to provide complete anesthesia at each stage, especially during obstetric operations and benefits. Should strive to shorten the period of labor. In the postpartum period, it is necessary to ensure the prevention of bleeding.
Discharge of patients with viral hepatitis E from the hospital and follow-up observation of convalescents is recommended, as in viral hepatitis A.
Prevention of Viral Hepatitis E
Particular importance is given to water disinfection. Measures of specific prophylaxis are not developed. There are recommendations for the introduction of specific immunoglobulin to pregnant women.