The article presents the results of analysis of reported incidence of acute and chronic hepatitis С in Russian Federation. Detailed description of current epidemiological characteristics of acute and chronic hepatitis С in various Federal regions and in different age groups is provided. The authors discuss the most probable transmission routs of HCV and its genotype distribution in Russia. Critical problems of laboratory diagnosis and hepatitis С surveillance are reviewed. There is an urgent need for introduction of HCV RNA as a routine confirmatory test for acute and chronic hepatitis С as well as introduction of Viral Hepatitis Registry for HCV patients throughout the entire territory of the Russian Federation.

In work, on the basis of the data of the literature on distribution of the new variant of flu A (H1N1) in comparison with materials about previously arising pandemics and the majority of epidemics in the 20th century, and also results of own supervision over disease rate and circulation of flu viruses since 1982 till the present time in the Primorsky Territory, an epidemiological estimation of the various hypotheses about factors and mechanisms of development of epidemic process of this infection has been given. Necessity of the ecological approach to consideration of a problem with flu has been proved.

On the base of long-term analysis ofprevalence of the hemorrhagic fever with renal syndrome (HFRS) and data of hantavirus infections in Apodemus mice - reservoirs ofpathogenic hantaviruses, the relation between of spatio-temporal peculiarities of prevalence of HFRS in Primorye Territory with activity of epizootic process in rodent populations during different phases of their population cycles has been established.

HIV infection is a major threat to national security of the Russian Federation. Unfavorable epidemiological situation of HIV infection and drug addiction in Russia leads to a significant increase in the number of conscripts, recognized unfitfor military service on health grounds in connection with this disease. The quantitative and structural indices of detection of HIV infection in people at the stage of recruitment and during the period of their service in the Armed Forces of the Russian Federation in the dynamics have been analyzed. The most detection rate of HIV infection in soldiers in the regions of the Russian Federation with high prevalence of HIV = disease has been established. With aim to prevent the carrying and further spread of HIV infection in the Armed Forces of the Russian Federation the performance of the mandatory medical examination ofpersons qualifying for induction has been suggested.

The article describes results of the analysis of incidence rate of hepatitis A in Russia and 29 European countries over the period 2001 to 2008. The characteristic of hepatitis A outbreaks as well as molecular genetic diversity of hepatitis A virus in Russia and Europe has been compared. The authors analyze the state of herd immunity to hepatitis A virus in population of the territories of countries mentioned above. The results of seroprevalence study of hepatitis A virus among different age groups in Moscow are presented. The critical role of hepatitis A vaccination in the system of prevention and disease control measures is emphasized.

The clinical features of the course of norovirus infection at various terms ofpregnancy in 65 examined women are presented in the article. In all patients moderate forms of disease prevailed. A characteristic of the clinical course, its peculiarities revealed in gravida, and complex therapy of norovirus infection are described.

152 cases of enteroviral meningitis in children aged 3 to 17years treated at the Infectious Diseases Hospital in Yaroslavl have been analyzed. The dominance of moderate forms of the disease with hypertension-hydrocephalic syndrome has been established. The combination with other clinical forms of enteroviral infection was rare, except for reactive pancreatitis. In patients with aseptic meningitis in the acute phase of illness an imbalance of cytokine profile due to increasing the production ofproinflammatory and reduction of the protective role of anti-inflammatory cytokines took place. Despite the relatively favorable course, a high risk of developing functional and organic disorders of the nervous system in a period of convalescence maintained, which creates conditions for the revision and supplement the standard protocols of treatment programs by including in them medicines of etiotropic targeting. The authors have developed regimens and performed the analysis of clinical and immunological efficacy of drugs with antiviral and interferonogenic action - arbidol and amiksin - in the content of complex basic therapy. In addition, the results of outpatient monitoring ofconvalescents 3 months after discharge from hospital have been analyzed. These data justify the need and desirability of inclusion of etiotropic drugs in standards of the basic therapy of enteroviral meningitis in children.

The data on clinical, ECG, ultrasound and laboratory features of myocarditides that developed in children with acute respiratory viral infections (ARVI) have been presented in this article. The dynamics of changes and the identified possibility of forming the chronic pathology in a one year after the onset of the disease has been shown.

Hyperactivaion of immme system is considered by most investigators as importantfactor, contributing to progression of HIV-infection and development ofAIDS. In the review modern knowledge about mechanisms and results of activation of immune system during HIV-infection are presented. HIV itself, opportunistic pathogens and components of gut microbiota, first of all, endotoxins ofgram-negative bacteria are considered as probable "activators" of immune system. High levels of endotoxin and markers of immune activation are associated with an even greater rate of progression of HIV-infection.

In a review article current data on the epidemiology, etiology, clinical picture of pneumonia in children are presented. The issues of the modern antibiotic and symptomatic therapy have been considered, and the features of immunological correction of this infectious disease in childhood also have been highlighted.

The significance of the problem of acute intestinal infections (AII) to date is associated with both their prevalence and high rate of adverse effects in the outcome of the disease. In modern literature there is enough information about the frequent occurrence in AII patients microbiota disorders, immune system imbalances, identifying signs of reactive changes ofpancreatic tissue and functional disorders of biliary tract, lactase deficiency, long-term disorders of functional activity of the digestive system. The data about AII as one of the factors of forming the gastrointestinal tract pathology, including irritable bowel syndrome have been accumulated.