Prognosis of the dynamics and intensity of the epidemic process in viral hepatitis A

The article deals with approaches to the calculation of the annual morbidity rate in virus hepatitis A at the period preceding the season of maximum morbidity, necessary for planning the relevant prophylactic and antiepidemic measures in due time. The method for calculating the monthly levels of sporadic morbidity in virus hepatitis A is proposed. This method permits the detection of complications on the epidemic situation, which is necessary for the timely organization of antiepidemic measures. The proposed method for predicting annual and monthly morbidity levels can be used in the practical work of specialists at sanitary and epidemic stations.     

Monthly dynamics of the epidemic process in viral hepatitis B

Monthly fluctuations in the number of registered cases of acute viral hepatitis B and HBsAg carriership have been studied. The study has revealed that, similarly to other infectious diseases, viral hepatitis is characterized by monthly fluctuations in the intensity of the epidemic process. Such fluctuations are characteristic of all known clinical forms of this infection; they are determined by the specific pathogenetic features of the process and by the ways of the transfer of the virus. The vernal rise of the infection is explained by activation of the manifest and asymptomatic chronic variants of the infectious process and, as the consequence of a rise in the number of asymptomatic cases, by a higher incidence rate of post-transfusion hepatitis infection. The autumnal rise of the infection results from the action of natural factors contributing to the transfer of the virus. Both rises are interrelated and interdependent. The seasonal fluctuations of the epidemic process should be taken into consideration when planning and implementing prophylactic and epidemic-control measures.     

Characteristics of the epidemic process manifested as chronic viral hepatitis

The incidence rates of chronic viral hepatitis in Leningrad over the period of 1962-1984 were studied. The tendency towards a rise in total morbidity because of increased incidence of chronic hepatitis B was shown to appear in recent years. This increase in morbidity was mainly due to its rise among adult males and children, which led to the shift of morbidity to younger age groups. The seasonal rises of morbidity in winter and spring were found to be characteristic of viral hepatitis.     

Circulating platelet activation in healthy subjects and in some pathological conditions. Method of study and results

Current clinical methods for evaluating platelet function are artful tests which study the effects of various stimuli on platelets, whereas the clinician is much more interested in methods evaluating the activation of circulating platelets. The hallmark of activation of platelets is their shape change, i.e. the transformation of the platelets from smooth disks into spiny spheres; the aggregation begins when 30% of platelets are activated. In 1138 subjects (384 healthy individuals and 854 patients with various pathological conditions with high thrombotic risk) we have investigated circulating platelet activation and circulating platelet aggregates by fixation of blood cells in a glutaraldehyde mixture and by evaluation of platelet shape change and aggregates on a phase-contrast microscope. The method is precise, accurate and suitable for clinical purposes.     

Self-regulation of the epidemic process in Pseudomonas aeruginosa infection under hospital conditions

The dynamics of the epidemic process of P. aeruginosa urinary tract infection at a urological clinic has been studied from the viewpoint of the theory of self regulation. Such approach to the study of the epidemic process under hospital conditions permits the detection of the risk factors, most important under given conditions.     

Patterns of the epidemic process in viral hepatitis A and B in territories with different morbidity levels. I. Hepatitis A

On the basis of data obtained by seroepidemiological studies general regularities, as well as essential differences, in the manifestations of the epidemic processes characterized by the active and sluggish spread of infection induced by hepatitis A virus have been revealed.     

Non-B hepatitis in Melbourne: a serological study of hepatitis A virus infection.

A study was performed to establish the value of immune adherence haemagglutination tests for antibody to hepatitis A virus in the diagnosis of non-B hepatitis. Infection with hepatitis A virus was confirmed in 14 out of 16 patients from six families and seven out of nine patients in whom the source of infection was unknown. One additional patient, who had had two episodes of jaundice, was shown to have had an attack of hepatitis A followed by an attack of hepatitis B. In patients with acute hepatitis A antibody detectable by immune adherence haemagglutination becomes detectable three or four weeks after the onset of symptoms and reaches peak levels about five weeks later.     

eIF2A mediates translation of hepatitis C viral mRNA under stress conditions

Translation of most mRNAs is suppressed under stress conditions. Phosphorylation of the α-subunit of eukaryotic translation initiation factor 2 (eIF2), which delivers initiator tRNA (Met-tRNA(i)) to the P site of the 40S ribosomal subunit, is responsible for such translational suppression. However, translation of hepatitis C viral (HCV) mRNA is refractory to the inhibitory effects of eIF2α phosphorylation, which prevents translation by disrupting formation of the eIF2-GTP-Met-tRNA(i) ternary complex. Here, we report that eIF2A, an alternative initiator tRNA-binding protein, has a key role in the translation of HCV mRNA during HCV infection, in turn promoting eIF2α phosphorylation by activating the eIF2α kinase PKR. Direct interaction of eIF2A with the IIId domain of the HCV internal ribosome entry site (IRES) is required for eIF2A-dependent translation. These data indicate that stress-independent translation of HCV mRNA occurs by recruitment of eIF2A to the HCV IRES via direct interaction with the IIId domain and subsequent loading of Met-tRNA(i) to the P site of the 40S ribosomal subunit.     

Basic patterns in the epidemic process of measles under conditions of massive immunization]

Observations over the measles epidemic process in Leningrad showed that the sporadic morbidity level reached in 1974--4.1 per 100 000 residents; however periodic elevation and decline of morbidity and tis seasonal variations persisted. A rise of morbidity in 1972--1973, and by preliminary data--in 1975, occurred on account of the older age groups. There was revealed no dependence of the disease incidence among the persons vaccinated on the time lapse after their vaccination. Individual batches of live measles vaccine issued in 1963--1969 were not up to the standard, this serving as one of the cases of the occurence of group incidence of the infection in some foci.     

Results of a comparative study of intestinal microflora in viral hepatitis patients

The data obtained in the bacteriological study of fecal microflora in 27 patients with hepatitis A and 44 patients with hepatitis B in the dynamics of the disease are presented. The study has established the presence of essential changes in the composition of intestinal bacterial flora in viral hepatitis patients, especially in cases of hepatitis B, due to the suppression of the growth of normal symbionts, mainly anaerobes, and to the multiplication of opportunistic ones.     

Study of serological and biological markers in viral hepatitis. 157 hemophiliacs

We observed for a two years period 157 hemophiliacs (138 with hemophilia A whose 13 were severe and 19 with hemophilia B whose 13 were severe) and we studied the incidence of liver dysfunction and the role played by HB and non-A, non-B, viruses. Whereas 32 patients not related had no evidence of serological HB virus markers (by radioimmunoassay), 88 (70,4 %) among the 135 hemophiliacs with large or small exposure to blood products were "HB positive". 90,9 % were positive for anti-HBs and anti-HBc antibodies and only two patients had persistent antigenemia. These results appeared independent of the kind of treatment (factor VIII or factor IX concentrates). Six among 17 children born since 1974, when the antigen was detected by RIA, had the serological HB virus markers, showing that this method is not sufficient to completely eliminate the HB virus. However the amount of viruses injected is too small to induce an acute hepatitis and rather produces specific antibodies which protect hemophiliacs against reinfection. An elevated level of serum transaminases (SGPT) was observed in 9,4 % of non treated hemophiliacs, 15,1 % of treated hemophiliacs with no serological markers of HB virus and 27,7 % of treated hemophiliacs "HB positive". This shows that the use of concentrates and the occurring of HB virus in the patients are not the only factors producing liver dysfunction. The role of non-A, non-B viruses has been recognized in 7 patients out of 9 with transient elevation of serum transaminase levels, by Trepo with an immunodiffusion technique.     

The epidemic process as a system. The social regulators of the epidemic process

The article deals with the mechanisms of spontaneous (urbanization, the international migration of population, the anthropogenic transformation of nature) and goal-oriented regulatory action on the epidemic process. Social factors have been shown to transform into ecological ones with the subsequent transformation of information in the parasitic system and their reflection in the social subsystem as the indices of the risk of infection and its socio-economical importance. Using the processes of urbanization as an example, the present work demonstrates that the mechanism of transmission acts as a filter whose specific features are determined by a range of social factors playing the most important role in the regulation of the epidemic process on the socio-ecosystemic level of its organization.     

Experience in the detection of the latent course of the epidemic process of viral hepatitis in children in preschool groups]

A complex study of 1273 healthy children of creches and kindergartens where no viral hepatitis occurred for a long time revealed 39 children (3.1%) with an increased activity of glutamine-pyroracemic transaminase in the blood serum. Viral hepatitis was diagnosed in 12 (0.94%) of them as a result of clinical examination (an icteric form in 1, and a nonicteric form in 11 cases). The presence of asymptomatic form of infection could be supposed in 17 other children (1.3%). The incidence of increased activity of the enzyme in the serum of "healthy" children was definitly connected with the viral hepatitis incidence registered in the town during the year as a whole, and by seasons. This permitted to prognosticate the spread of viral hepatitis in the given populated locality. By complex laboratory examination of children in collective bodies it was possible to detect the latene foci and the latently coursing epidemic process of viral hepatitis.     

The epidemic process as a system. I. The structure of the epidemic process

A new epidemiological concept (socio-ecological) has been formulated on the basis of the principles of the theory of systems and the theory of information. In accordance with this concept, the epidemic process is organized on the same principle as living matter, and the stability of this process at all levels of its organization is ensured by the processes of self-regulation. The conditions of the life of human society have been shown to be organically incorporated into the structure of the epidemic process as a regulating subsystem on the socio-ecological level.     

Determination of metabolic equivalents during low- and high-intensity resistance exercise in healthy young subjects and patients with type 2 diabetes

The purpose of this study was to quantify the metabolic equivalents (METs) of resistance exercise in obese patients with type 2 diabetes (T2DM) and healthy young subjects and to evaluate whether there were differences between sessions executed at low- versus high-intensity resistance exercise. Twenty obese patients with T2DM (62.9±6.1 years) and 22 young subjects (22.6±1.9 years) performed two training sessions: one at vigorous intensity (80% of 1-repetition maximum (1RM)) and one at moderate intensity (60% of 1RM). Both groups carried out three strength exercises with a 2-day recovery between sessions. Oxygen consumption was continuously measured 15 min before, during and after each training session. Obese T2DM patients showed lower METs values compared with young healthy participants at the baseline phase (F= 2043.86; P<0.01), during training (F=1140.59; P<0.01) and in the post-exercise phase (F=1012.71; P<0.01). No effects were detected in the group x intensity analysis of covariance. In this study, at both light-moderate and vigorous resistance exercise intensities, the METs value that best represented both sessions was 3 METs for the obese elderly T2DM patients and 5 METs for young subjects.     

Role of genetic factors in the epidemic process in respiratory viral infections

Observations carried out during 1973-1979 indicate that persons, who are frequently ill, determine the incidence of influenza and acute respiratory diseases among various groups of adult population at all epidemic periods. In constantly observed groups of different ages such persons were the source of 60-85% of the outbreaks of acute respiratory diseases. The correlation between genotypic blood markers (the ABO and HLA systems) and susceptibility to respiratory viruses has been established.     

The epidemiological differential diagnostic signs of viral hepatitis A and viral hepatitis E]

A retrospective epidemiologic analysis of cases diagnosed as hepatitis A (HA) has been made in territories characterized by high intensity (4 towns in Central Asia) and low intensity (Novomoskovsk, Tula Province) of the epidemic process development. Morbidity structures for different age and social groups of the population, as well as the morbidity time course, both annual and over many years, were analyzed over 1973-1986. Specific features in the development of the epidemic process in HA and hepatitis E (HE), formerly called hepatitis non-A, non-B with the fecal/oral mechanism of the infection transmission, were studied. Twelve epidemiological differential diagnostic signs of these two infections were formulated, classified, and validated. Contribution of centralized water supply and sewage systems to the development of HE epidemic process and the regulating role of infectious immunological mechanisms in the development of HA epidemic process were demonstrated.