[The possible involvement of rodents in the spread of viral hepatitis E]. / Vozmozhnoe vovlechenie gryzunov v rasprostranenie virusnogo gepatita E.

The outbreak of hepatitis E among humans in July-October 1989 in the village of Dzhigdele (140 km to the northeast of Osh) is described. During this outbreak 23 rodents of different species (4 Turkestan rats, 15 house mice and 4 wood mice) were caught within a radial distance of 1 km from the village. 5 out of these 23 animals were found to have hepatitis E virus, detected by the method of immuno-electron microscopy, in their blood sera. Under experimental conditions 7 noninbred white mice were inoculated with material obtained from a previously infected Javanese macaque and a hepatitis E patient. The use of immunoelectron microscopy made it possible to reveal the excretion of the virus with feces on days 4 to 19-23 after inoculation and the development of specific seroconversion in all 7 infected animals. On the basis of these data a suggestion was made that rodents probably played a certain role in the process of the spread of viral hepatitis E.

[The clinical picture, course and outcome of viral hepatitis A in children with chronic HBV infection]. / Klinika, techenie i iskhody virusnogo gepatita A u detei s khronicheskoi HBV-infektsiei.

The clinical picture, course and outcomes of hepatitis A developing as a superinfection in children with chronic hepatitis B virus (HBV) infection, hospitalized in connection with acute viral hepatitis, were determined on the basis of the dynamic clinico-laboratory investigation and identification of viral hepatitides A, B and delta by the method of enzyme immunoassay. In all children hepatitis B virus surface antigen (HBsAg), i.e. the serological sign of HBV infection, and anti-HAV IgG, the serological sign of hepatitis A virus (HAV) infection, were present in the blood. 11 out of 12 children had never before been examined for diseases of the liver. Only in one child chronic HBsAg carriership had been detected 14 months before this hospitalization. Considering the data of epidemiological history and clinical observations, as well as the results of serological survey, these children were found to have hepatitis A superimposed on chronic HBV infection. As revealed in the present investigation, in cases of HAV superinfection observed simultaneously with chronic hepatitis B viral hepatitis A was manifested by typical clinico-laboratory symptoms.

[The development of the epidemic process and the formation of humoral immunity to the hepatitis A virus in adolescent collectives]. / Razvitie épidemicheskogo protsessa i formirovanie gumoral'nogo immuniteta k virusu gepatita A v podrostkovykh kollektivakh.

Additional observation on the formation of humoral immunity to hepatitis A virus has been carried out in 2,375 adolescents aged 15-17 years and belonging to 12 groups at 3 areas of the USSR. This observation has shown that in the presence of a high level of the immune stratum the spread of infection occurs, as a rule, outside the group under observation. Besides, as revealed in this study, the risk of seroconversion and the loss of specific antibodies are, respectively, directly and inversely related to the level of the immune stratum in the group. The level of the immune stratum in a given age group supposedly reflects the intensity of the development of the epidemic process at a definite area.

[Patterns in perinatal infection with the hepatitis B virus in areas contrasted by the level of HBsAg and HBeAg carriage]. / Zakonomernosti perinatal'nogo infitsirovaniia virusom gepatita B na territoriiakh, kontrastnykh po urovniu nositel'stva HBsAg i HBeAg.

In 1984-1988, the levels of HBsAg carrier state and the status of the "e"-system components in pregnant women in Moscow and in the Uzbek SSR, as well as the rate of infection with hepatitis B virus (HBV) in babies born to women carriers of HBsAg in regions with different levels of HBsAg and HBeAg carrier state were studied. The levels of HBsAg carrier state among pregnant women were different in Moscow and Uzbekistan (1.1% and 6.9%, respectively). It was noted that in female HBsAg carriers in these regions the rate of HBeAg detection differed greatly: 5.2% in Moscow and 13.9% in Uzbekistan. The frequency of perinatal infection with HBV in Moscow was 26.1%, in Uzbekistan 40.0%, the frequency of persistent carrier state of HBsAg in the infected babies of Uzbekistan was 16.0%. The possibility of formation of HBsAg persistence in babies born to women with HBsAg and anti-HBe in the blood was demonstrated. The problem of the use of specific prophylaxis measures to prevent perinatal transmission of HBV is discussed.

[Development of an infection in monkeys as a result of their sequential natural and experimental exposure to the hepatitis A virus]. / Razvitie infektsii u obez'ian v rezul'tate posledovatel'nogo estestvennogo i éksperimental'nogo zarazheniia ikh virusom gepatita A.

The development of spontaneous outbreak of hepatitis A (HA) among African green monkeys kept under strict isolation conditions was studied. It was shown that in the case of introduction of HAV the infection involved all the susceptible monkeys, running a course with and without any increase in the level of activity of serum alanine aminotransferase (ALT) After inoculation of commercial gamma-globulin only the infection without the ALT activity increase developed and some monkeys had no signs of HA at all. Experimental reinfection with HAV was produced in monkeys having anti-HAV titres of less than or equal to 1:3500.

[Epizootic hepatitis A among African green monkeys kept in a vivarium]. / Epizootiia gepatita A sredi afrikanskikh zelenykh martyshek, soderzhashchikhsia v usloviiakh vivariia.

The results of observations on the pattern of spread of hepatitis A virus and immune response to it in African green monkeys (Cercopithecus aethiops) kept in the animal house are presented. The infection in the monkeys was found to be characterized by all virological, serological, and biochemical parameters inherent in hepatitis A virus. The results indicated that hepatitis A in monkeys may run both asymptomatic and clinically manifest course, and the spread of infection in the animal house sequentially involves most seronegative animals into the epidemic process.

[Protracted forms of viral hepatitis A in adolescents]. / Zatiazhnye formy virusnogo gepatita A u podrostkov.

The results of study of the clinical picture and outcomes of type A viral hepatitis (HA) in 80 male adolescents aged 15-18 years are presented. The diagnosis was confirmed serologically. A greater incidence of the protracted forms of HA has been found in adolescents which in most cases had a favourable outcome. Protracted hepatitis was marked by long-term persistence of anti-HVA IgM. The chronic form of viral hepatitis had a course of a mixed A and B viral infection.

[Study of human and simian hepatitis A virus isolated by an immunoenzyme method using polyclonal and monoclonal antibodies]. / Issledovanie izoliatov virusa gepatita A chelovecheskogo i obez'ian'ego proiskhozhdeniia immunofermentnym metodom s ispol'zovaniem poliklonal'nykh i monoklonal'nykh antitel.

Hepatitis A viruses (HAV) isolated from man and Old World monkeys varied in their interaction with monoclonal antibodies (MCA) in enzyme immunoassay. All human HAV isolates reacted with the MCA under study (HIC19, H7C27, and K3-4C8), whereas the viruses isolated directly from monkeys did not react with H7C27 MCA and some of them also with H1C19 MCA. Simian HAV strains became capable of reacting with H7C27 MCA and H1C19 MCA after adaptation to cell culture. In tests with human and simian immune sera (polyclonal antibody to HAV) a number of human isolates interacted with human serum antibodies much more intensively and with simian serum antibodies.

[Characteristics of the development of humoral immunity to hepatitis A in children's day care centers]. / Osobennosti formirovaniia gumoral'nogo immuniteta k gepatitu A v kollektivakh detskikh doshkol'nykh uchrezhdenii.

Solid-phase enzyme immunoassay was used to study changes in the frequency and levels of antibody to hepatitis A virus (anti-HAV) in 567 children in 20 isolated groups of 5 day-care centers of the town of Kemerovo. The observation period included the seasonal rise in hepatitis A incidence. An increase in the portion of seropositive children occurred in the groups where manifest or asymptomatic infection with hepatitis A existed. The number of seropositive subjects in the groups where the children were given immunoglobulin by epidemiological indications increased by 0-8%, and in those without immunoglobulin by 11-37.5%. The passive antibody received with immunoglobulin were detected in the originally seronegative children and declined to undetectable levels within 2 months. Subsequently, no clinical cases of hepatitis A or asymptomatic seroconversions were observed in these children. Some cases of reinfection showing an increase in anti-HAV levels but without clinical manifestations of hepatitis A were detected.

[Signs of natural infection with hepatitis A in brown macaques (Macaca arctoides)]. / Priznaki estestvennoi infektsii gepatita A u burykh makak.

The results of examinations of stump-tailed monkeys (M. arctoides) held in captivity are presented. The presence and levels of anti-HAV and anti-HAV class M in the blood sera of monkeys were determined by the enzyme-immunoassay (EIA), and alanine aminotransferase (AIAT) activity was measured. HAV in stool specimens collected from the monkeys was detected by immune electron microscopy and EIA. In the first examination, 2 out of 10 monkeys were found to have anti-HAV and one of them to have anti-HAV class M. In repeat examination of 4 monkeys 32 days later, two of them showed an increase in AIAT and 3 had HAV in stools. In the 3rd examination in 91 days, all the four animals had anti-HAV and anti-HAV class M. Besides, three seronegative monkeys out of the ten examined initially, showed only total anti-HAV in 91 days. At the time of the 3rd blood specimen collection, 16 more monkeys were examined and all of these had anti-HAV but not anti-HAV class M. It is assumed that natural infection of stumptailed monkeys in captivity with a virus antigenically identical to HAV is possible.

[Use of a cocultivation method for detecting cytomegalovirus contamination of cell cultures of simian origin]. / Ispol'zovanie metoda sokul'tivirovaniia dlia vyiavleniia tsitomegalovirusnoi kontaminatsii kletochnykh kul'tur obez'ian'ego proiskhozhdeniia.

At present, nonanthropoid primates are widely used as sources of cell cultures for manufacture of live viral vaccines. Simian cell cultures, particularly kidney cell cultures are also known to be frequently contaminated with cytomegaloviruses. The isolation of the latter is rather difficult due to the late appearance of the cytopathic effect in cell cultures of natural hosts. In the present study, the sensitivity of 4 methods virus isolation from the test cells was compared: the method of long-term cultivation of cells; the method of long-term cultivation with one subpassage of the cells; the method of cocultivation of the test cells by mixing with sensitive cells; and the method of co-cultivation by overlaying the test cells on an incomplete monolayer of sensitive cells. The latter method shortened the observation period and yielded a higher percentage of isolation of contaminating viruses from African green monkey kidney cell cultures. This method is supposed to be used in future for the detection of viral contamination of African group monkey kidney cell cultures utilized in manufacture of live viral vaccines.