Abstract. Hepatitis B virus is a serious issue of public health services all over the world, particularly in Russia and its regions. The cause can be determined due to its higher incidence rate in different ethnic and geographical groups, variety of manifestation of clinical forms as well as outcomes. According to WHO data, about 50 million people in the world are annually infected with hepatitis B virus. Development of molecular-genetic methods of research has allowed to expand representations about the activator biology. Genetic variability of hepatitis B virus genome has been subject to identification of 10 various geographically widespread genotypes designated by letters from A to J. In a number of genotypes subgenotypes differing from one another on 4–8% full genome sequences are revealed. In the work a table of geographical prevalence of various genotypes of hepatitis B virus in the world is presented. The geographic distribution of genotypes of hepatitis B virus is closely connected with endemic regions and indigenous population, living there. So the genotypes B and C are connected with the population of Asian countries, genotypes A and D are extended among European countries and in the USA. The genotype D is considered to be a prevailing type among patients with hepatitis B in several regions of Turkey. The phylogenetic analysis of nucleotide sequences of hepatitis B virus isolates in African regions has shown presence of three subgenotypes — А1, А2, А3. In the countries of Asia the following six subgenotypes B are noted: В1 in Japan, В2–В5 and В7 in East Asia Subgenotip B6 is found among indigenous population living in the Arctic regions, including Alaska, northern Canada and Greenland. The genotype C has five serotypes (С1–С5) which are extended in East and South East Asia. The genotype D, also has five subgenotypes (D1–D5) which are extended in Africa, India, the Mediterranean region, Europe. Genotype F has four subgenotypes (F1– F4) which circulate in Central and the South America. Subgenotypes are not revealed among genotypes E, G, H, I and J. In the territory of the Russian Federation the highest incidence of hepatitis B virus is noted in 3 genotypes (A, C, D). Among them the genotype D comprising 88% of them is the prevailing one.

Hepatitis C virus (HCV) infection is one of the most prevalent health problems in the world. Official registration of HCV infections in the Russian Federation started in 1994. Two clinical forms of infection - acute and chronic hepatitis C - are registered separately. Moreover, the HCV national surveillance system also includes reports from laboratories on results from testing similar to 20 population risk groups for antibodies to HCV; approximately 15-16 million tests are performed annually. Modern epidemiological features of HCV infection in the Russian Federation are characterized by low incidence of the acute form of infection (acute HCV; one to two per 100,000) and a dramatic increase in chronic HCV (CHCV) cases. In 2013, the average nationwide rate of newly detected CHCV cases was 39.3/100,000. In the same year, the prevalence of CHCV demonstrating an accumulation of chronically infected patients in the country was much higher -335.8/100,000. Four risk groups were identified as greatly affected by HCV, which were demonstrated by a high prevalence of antibodies to HCV: newborns from chronically infected women, persons from correctional facilities, patients with chronic liver diseases, and clients from clinics for sexually transmitted disease patients and drug users. It was found that several HCV genotypes circulated in different regions of the country; HCV1b had a prevalence of 55%-80% in almost every part of the country. However, in St Petersburg during the final decade of the last century and from 2001-2005, HCV3a subtype expanded circulation among young people due to increased intravenous drug addiction. Intravenous drug users were the major cause of a higher registration of double infection, with two different virus subtypes, and the appearance in Russia of new recombinant virus RF_ 2k/1b. It can be concluded that CHCV infection should be a focus of the health care system in Russia because serious epidemics of liver cirrhosis and hepatocellular carcinoma will be seen in the near future that will require urgent preventive and therapeutic measures.

In recent years, there were published several epidemiological observations concerning the maximum incidence of hepatitis A (HA) shifting into the older age groups, including adolescents aged 15-19 and young adults 20-39 years old, and the reduction of the role of children as a significant risk group. These phenomena have not been sufficiently studied yet and have not received an adequate explanation. The aim of this study is to investigate the age characteristics of the epidemic process of the HA in Russian Federation and federal districts in the modern period to assess the need for routine vaccination of children against the infection, as well as to determine the optimal age for its implementation. There was conducted a comparative analysis of age-related morbidity of Hepatitis A (the proportion of children and adults, the ratio of adults and children’s rates, the intensity of the population) in the federal districts of the Russian Federation in 1999, 2001 and 2010. It was discovered that Hepatitis A remains a significant child problem in Russian Federation. The proportion of children aged 0-14 years among Hepatitis A cases in 2010 (28%) was not significantly different from that in 1999 (40%). In the Far East, Siberia and the North Caucasus the incidence of children is continuously increasing 4-6 times faster than those of adults. These characteristics of the epidemic process of Hepatitis A indicate the need for the introduction of a routine vaccination of children.

Since discovery of Hepatitis C virus in 1989 and starting of official registration of acute and chronic cases of Hepatitis C (HC) in the Russian Federation in 1994 there are a lot of data demonstrating epidemic process development of HCV infection in the country as well as features of HCV epidemiology.

Since discovery of Hepatitis C virus in 1989 and starting of official registration of acute and chronic cases of Hepatitis C (HC) in the Russian Federation in 1994 there are a lot of data demonstrating epidemic process development of HCV infection in the country as well as features of HCV epidemiology.

Abstract. Hemo-contact viral hepatitis B and C is significant public health problem in hospitals and particularly in hemodialisys units. To define modern situation of the problem the retrospective study of viral hepatitis B and C registration in hemodialysis units in Saint-Petersburg in 1997–2007 as well as testing of 295 patients from four units for serological markers of hepatitis B and C (HBsAg, anti-HBs, anti-HBc, anti-HCV) have been conducted. It was determined that registration of hepatitis B in the study period was 5,2 cases per 1000 patients/per year, hepatitis C — 8,2 cases per 1000 patients/per year. These rates were significantly higher than in the total city population. The serological markers of ongoing or past HBV/HCV infection were revealed in 78,3 per 100 patients. Obtained results confirm intensive viral circulation in hemodialysis units. Additional study of transmission routes using molecular epidemiology techniques is required.

The study was aimed to evaluate vaccine prevention of hepatitis A in occupational risk groups in Russian Federation over 2011-2013. Epidemiologic analysis method was used. Data array for the analysis included information about 1,162,619 individuals vaccinated against hepatitis A throughout the country. Findings are that during the studied period a total of 470,278 adults over 18 years were vaccinated (i.e., 0,4% of all population of this age). Among occupational risk groups subjected to anti-hepatitis A vaccination within immunization calendar on epidemic indications, major (29%) share was presented by catering enterprises workers and individuals engaged into food trade and supply. Other occupational risk groups (workers maintaining water supply systems and sewerage system, medical staff, preschool institution teachers, etc) demonstrated significantly lower levels of being vaccinated. Vaccination against hepatitis Ain occupational risk groups should be in a focus of prophylactic measures, as will help to control over hepatitis A spread.

AIMDetermine the frequency of antibodies to surface (anti-HBs) and core (anti-HBc) antigens of hepatitis B in population of St. Petersburg of various age for evaluation of protective herd immunity against hepatitis B virus (HB).MATERIALS AND METHODSBlood sera of 970 individuals (491 males, 479 females) of 10 age groups from 0 to 50 years and older were examined for the presence of anti-HBs and anti-HBc IgG by enzyme immunoassay using commercial diagnostic test-systems.RESULTSIn general anti-HBs at the level of 5 mIU/ml and above were detected in 603 of the examined individuals (62.2%). Anti-HBs at the level of 10 mIU/ml and above were detected in 53.9%. The frequency of anti-HBs in protective titers in males and females in general turned out to be similar (52.6% and 55.2%, respectively). Juxtaposition of age-specific parameters of seroprotection and acute HB morbidity in St. Petersburg revealed an inverse correlation of medium strength (r = - 0.54).CONCLUSIONResults of the study confirm high effectiveness of the program of HB vaccine prophylaxis in St. Petersburg and emphasize the necessity of further implementation of broad measures of population immunization against HB.

Heterogeneity of hepatitis B virus and its link with clinical course of infection and its outcomes remains one of priority directions of researches in Republic Sakha (Yakutia), as the region with high incidence of this disease. Blood serum samples with chronic hepatitis, registered in dispensary of various regions of the Republic Sakha (Yakutia), have been investigated. On the basis of results of the research by means of molecular - biological methods in the republic a genotype D was considered as the dominating genotype at patients with CHB, and sufficiently a large number of patients are infected simultaneously by two genotypes, most intensively circulating in the territory of Republic (A, D, C). For adequate therapy of such diseases it is necessary to consider characteristics of excreted isolates.

Abstract. The information concerning incidence, prevalence and morbidity of chronic viral hepatitis (CVH) in the territories of the Russian Federation for the period 1999–2009 is presented in the analytical review. The special attention is paid to multiyear dynamics of CVH registration, to diseases distribution by the Federal areas and separate territories as well as to CVH incidence in different age groups.

Abstract. Hemo-contact viral hepatitis B and C is significant public health problem in hospitals and particularly in hemodialisys units. To define modern situation of the problem the retrospective study of viral hepatitis B and C registration in hemodialysis units in Saint-Petersburg in 1997–2007 as well as testing of 295 patients from four units for serological markers of hepatitis B and C (HBsAg, anti-HBs, anti-HBc, anti-HCV) have been conducted. It was determined that registration of hepatitis B in the study period was 5,2 cases per 1000 patients/per year, hepatitis C — 8,2 cases per 1000 patients/per year. These rates were significantly higher than in the total city population. The serological markers of ongoing or past HBV/HCV infection were revealed in 78,3 per 100 patients. Obtained results confirm intensive viral circulation in hemodialysis units. Additional study of transmission routes using molecular epidemiology techniques is required.

Recently epidemiological data on maximal hepatitis A (HA) morbidity values shift to older age groups, including adolescents at the age of 15–19 years and young adults at the age 20–39 years, and decreasing significance of children as a risk group have been published. These phenomena have not been well studied and do not have satisfactory explanations. The aim of this study was to evaluate age dependent characteristics of epidemiological process of HA in Russian Federation and its federal districts during the current period of time and to determine the necessity and appropriate age of scheduled vaccination against this infection in children. The comparative analysis of age-dependent values of HA morbidity (percentage of children and adults, the rate of adults and children values, intensity) of the population in federal districts of Russian Federation in 1999, 2001 and 2010 was performed. It was established, that HA is still a significant challenge in children health in Russian Federation. The percentage of children at the age of 0–14 years among the developed the disease in 2010 (28%) does not differ significantly from that in 1999 (40%). In Far Eastern, Siberian and North-Caucasian federal districts the children morbidity constantly 4–6 times exceeds the respective values in adults. Such characteristics of HA epidemiology indicate the necessity of scheduled vaccination of children against this infection.

Recently epidemiological data on maximal hepatitis A (HA) morbidity values shift to older age groups, including adolescents at the age of 15–19 years and young adults at the age 20–39 years, and decreasing significance of children as a risk group have been published. These phenomena have not been well studied and do not have satisfactory explanations. The aim of this study was to evaluate age dependent characteristics of epidemiological process of HA in Russian Federation and its federal districts during the current period of time and to determine the necessity and appropriate age of scheduled vaccination against this infection in children. The comparative analysis of age-dependent values of HA morbidity (percentage of children and adults, the rate of adults and children values, intensity) of the population in federal districts of Russian Federation in 1999, 2001 and 2010 was performed. It was established, that HA is still a significant challenge in children health in Russian Federation. The percentage of children at the age of 0–14 years among the developed the disease in 2010 (28%) does not differ significantly from that in 1999 (40%). In Far Eastern, Siberian and North-Caucasian federal districts the children morbidity constantly 4–6 times exceeds the respective values in adults. Such characteristics of HA epidemiology indicate the necessity of scheduled vaccination of children against this infection.

The incidence of Hepatitis A still remains one the highest among other types of viral hepatitis in many countries in the world including Russia. An important epidemiological trait of the disease is its high prevalence among children. This article contains results of the comparative analysis of prevalence of hepatitis A in two indicator groups children 3-6 years old and adults 20-29 years old from 78 regions of the Russian Federation. Antiviral collective immunity was assessed by the levels of IgG to hepatitis A virus (anti-HAV) in 2009 among children 0-17 y. o. and adults 20-39 y. o. from St. Petersburg (in total among 872 patients). Judging upon incidence of hepatitis A infection and rate of anti-HAV detection it was stated that St. Petersburg is a region with interim endemicity that requires planned immunization according to the WHO recommendations.

The incidence of Hepatitis A still remains one the highest among other types of viral hepatitis in many countries in the world including Russia. An important epidemiological trait of the disease is its high prevalence among children. This article contains results of the comparative analysis of prevalence of hepatitis A in two indicator groups — children 3–6 years old and adults 20–29 years old from 78 regions of the Russian Federation. Antiviral collective immunity was assessed by the levels of IgG to hepatitis A virus (anti-HAV) in 2009 among children 0–17 y. o. and adults 20–39 y. o. from St. Petersburg (in total among 872 patients). Judging upon incidence of hepatitis A infection and rate of anti-HAV detection it was stated that St. Petersburg is a region with interim endemicity that requires planned immunization according to the WHO recommendations.Key words: children, hepatitis A, incidence, epidemiology.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2011; 10 (3): 131–136)

AIM To determine immune structure of different population groups in Saint-Petersburg to hepatitis A virus in 2009 in order to study trends of epidemic process dynamics and planning of prophylactic measures. MATERIALS AND METHODS Nine hundred and three citizens of Saint-Petersburg aged 3 months to 60 years were tested for anti-HAV by ELISA in 2009. Results were compared with data of previous study conducted in Saint-Petersburg in 1999. Two hundred injection drug users (IDUs) aged 14 - 29 years were tested additionally. RESULTS In total in 2009, anti-HAV were detected in 32.5 +/- 1.6% citizens of Saint-Petersburg that is 2-fold lower than in 1999 (60.2 +/- 1.5%). Especially sharp decrease of anti-HAV prevalence in 2009 compared to 1999 was observed in age groups 15 - 19 years (by 2.6-fold), 20 - 29 years (by 3.1-fold), and 30 - 39 years (2.8-fold). Anti-HAV were detected in 58.5 +/- 3.5% of tested IDUs that 2.8-fold higher of that value observed in persons 14 - 29 years old from population sample (21.7 +/- 2.4%). CONCLUSION Decrease of immunity to HA in population of Saint-Petersburg is very unfavorable prognostic factor pointing to strong possibility of HA outbreaks onset during worsening of epidemic situation. In such circumstances, active immunization against HA of wide strata of population should become important prophylactic measure.