[Th1-cytokines in chronic hepatitis B and C]. / Th1-tsitokiny pri khronicheskikh formakh virusnykh gepatitov B i C.

Forty-four patients with chronic HBV and HCV were observed. Serum levels of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), and soluble IL-2 receptor (IL-2r) were measured by enzyme immunoassay in 29 patients divided into 3 groups: group 1 (n = 9) with chronic HBV, group 2 (n = 9) with chronic HCV, and group 3 (n = 11) with mixed HBV + HCV infection. Control group consisted of 10 normal subjects without HBV, HCV, or HIV infection markers. The most informative of Th1 cytokines was IL-2r: its concentration was increased significantly (p < 0.01) in all patients with hepatitis B and/or C in comparison with the control. In addition, there was a trend to an increase in the mean concentrations of IL-2r from group 1 to groups 2 and 3. The concentrations of IFH-gamma and IL-2 did not differ significantly in the patients and controls. However, the concentrations of IFN-gamma were increased significantly (p < 0.01) in comparison with the control in 3 patients from group 1 and 4 patients from group 3 with more pronounced inflammation.

[Hepatitis A in Estonia (1990-1999)]. / Gepatit A v Estonii (1990-1999).

During recent 10 years (1990-1999) essential changes occurred the epidemiology of viral hepatitis A (VHA) in Estonia: simultaneously with a decreased level of morbidity (morbidity rate per 100,000 of the population was 78.4 in 1990 and 7.7 in 1996, or 1,241 and 112 cases, respectively), a shift in the age structure of patients from children of preschool age to older age groups took place. Everyday contacts were the main established route of VHA transmission in recent years, but in more than 80% of cases the risk factors of the virus transmission remained obscure. During the regional outbreak of VHA in North Estonia in 1998 (937 out of 989 cases registered in the country) a rise in morbidity was observed among young people aged 15-29 years, when a wide spread of parenteral viral hepatitides B and C and drug addiction were registered in this region. During this outbreak VHA was transmitted mainly through everyday contacts. Still the considerable prevalence of injection drug users who practiced the group use of syringes and needles and took drugs from common containers, a sufficiently high level of the mixed forms of the disease (more than 18% of all registered cases of VHA), detected for the first time, make it possible to suggest that the parenteral transmission route could appear among persons belonging to the above mentioned group. Vaccination is regarded as the most effective measure for the prophylaxis of VHA.

[The epidemiological aspects of viral hepatitides in Estonia]. / Epidemiologicheskie aspekty virusnykh gepatitov v Estonii.

The etiological structure of viral hepatitides among the adult population of Tallinn and the occurrence of markers of hepatitis B and hepatitis C virus infections in medical workers, addict introducing drugs intravenously and hemodialysis patients were studied. Changes in the etiological structure of viral hepatitides were established: they took the form of a decrease in the level of hepatitis A morbidity and the considerable growth of the role of hepatitides B and C, as well as the newly detected circulation hepatitis D virus. About one-third in the structure of morbidity in viral hepatitides were hepatitis cases without markers of hepatitis A, B or C viruses (non-A, non-B, non-C). The highest rates of hepatitis B virus infection (78.9%) and hepatitis C virus infection (82.5%) were detected among drug addicts. Their level of HBsAg was 8.8%. In the group of medical workers, 25% of the examinees, i.e. every fourth person, had markers of hepatitis B virus, while antibodies to hepatitis C virus were detected in 5% of cases. Among hemodialysis patients these rates were 21.4% and 10.7% respectively.

[Measles morbidity among children inoculated against this infection]. / O zabolevaemosti kor'iu privitykh protiv étoi infektsii detei.

In the serological survey of 2009 children immunized against measles 285 children (14.2%) were found to be seronegative to this infection in the hemagglutination inhibition test with 4 hemagglutinating units of the antigen. Among 1724 immunized children showing positive response to vaccination and placed under dynamic observation for 11 years, 2 cases of measles were registered. At the same time, in the dynamic observation of 111 seronegative children 66 measles cases (59.5%) were registered during the above period, while among 169 children, also seronegative, but receiving booster immunization against measles, morbidity rate was only 1.2%. In some vaccinees the decrease of postvaccinal immunity to seronegative values was observed, but such decrease had no essential influence on the morbidity level among the vaccines. The increase of measles morbidity among schoolchildren immunized against this infection was due not to the decrease of their postvaccinal immunity, but to their concentration in schools and to their more intensive contacts with the sources of infection in comparison with children of preschool age.