Relevance. Measles infection still does not lose its relevance, as experts everywhere register outbreaks of the disease. The aim of the study is characterization of the measles epidemic process in the context of different strategies for its vaccination in a large industrial city to make adequate management decisions.Materials and methods. The authors used the data of statistical reports on measles incidence in Yekaterinburg in 1950–2017 as the study materials. The authors analyzed data for six periods: pre-vaccination (1950–1961), selective immunization (1962–1965), routine vaccination of children under 8 years (1966–1972), vaccination of children under 14 years (1973–1986), the introduction of mass revaccination of children (1987–2001) and the period of universal vaccination at the stage of elimination of infection (2002–2017).Results. In the pre-vaccination period, the average annual incidence rate was 1381.7 ± 162.9 per 100 ths population, the seasonal increase in the incidence was in december–may, in the structure of age groups dominated by children. During the period of selective immunization, at the stage of testing of the domestic vaccine, there was a slight decrease in the incidence to 1082.8 ± 189.1 per 100 ths population, intra-annual dynamics and age distribution of patients remained virtually unchanged. During routine vaccination of children up to 8 years of age, there was a significant reduction in the incidence to the level of 219.8 ± 110.8 per 100 ths population , which was observed in almost all age groups, with the exception of children 10–14 years and adults. Seasonal manifestations of the epidemic process were similar to previous periods. With an increase in the cohort for vaccination at the expense of children up to 14 years, there was a further decrease in the incidence to 89.9 ± 39.1 per 100 ths population, but in some years measles outbreaks were registered, with an active spread of infection among schoolchildren in educational institutions. The decision to introduce a second vaccination for 6-year olds before school made it possible to achieve a sporadic level of morbidity and to change the main parameters characterizing the epidemic process in all previous periods. The epidemic process has become intermittent. Periodic rises disappeared. When the infection was not spread, the population immunity and vaccination rates were consistent with the recommendations of who experts. However, against this background, 2016 was registered a major outbreak of measles.Conclusion. The use of different tactics of vaccination led to significant changes in the parameters of the epidemic process of measles. However, at the present stage immunization schemes do not control the situation. In this regard, it is necessary to raise the issue of introduction of revaccination against adult measles every 10 years, as well as changes in the antigenic composition of the live measles vaccine, taking into account data on circulating strains of the virus of genetic lines D and H.
Relevance. During the pandemic of the new coronavirus infection (COVID-19), one of the most vulnerable and actively involved in the epidemic process categories of the population were medical workers. The study of the incidence of COVID-19 among medical workers, risk factors for infection and safety measures is an important area of research in modern conditions. The aim of the study is to assess the prevalence of COVID-19 among employees of medical organizations and occupational risk factors for infection in order to develop proposals for corrective measures. Materials and methods. To study the incidence of COVID-19 among employees of medical organizations, an anonymous online questionnaire developed by the authors was used, which was posted on the Google platform and distributed during the first wave of the pandemic among employees of medical organizations in several regions of the Russian Federation through corporate e-mail or specialized online resources adapted for health workers. The survey involved 1,872 medical workers of different genders, ages, positions and work experience. Results and discussion. Among the survey participants, 161 employees have already had a new coronavirus infection. In the majority (64.0%) of them, the disease occurred in the form of acute respiratory infection, in 28.6% - interstitial pneumonia, in 7.4% only the fact of isolation of the SARSCoV-2 antigen without clinical manifestations of infection was documented. The most affected contingents were secondary and junior medical personnel, mainly hospital staff. The likelihood of infection in the workplace was increased by factors such as providing care to patients with confirmed COVID-19, participating in procedures related to aerosol generation, working with biomaterials of patients with COVID-19, contact with surfaces in the environment of a COVID-19 patient, ignorance of infectious safety issues due to lack of instruction before admission to work. When assessing the efficiency of personal protective equipment (PPE) when they are used in the process, it was found that the highest value for the prevention of infection COVID-19 had a PPE for face protection, respiratory and eye, and hand hygiene. At the same time, many employees are faced with the problem of an insufficient number of protective equipment in the workplace. When assessing the availability of SARS-CoV-2 testing to employees, it was found that only 77.4% of survey participants had the opportunity to be tested for coronavirus infection in a timely manner. Conclusion. Thus, for more effective protection of employees of medical organizations, it is necessary to have a sufficient number of personal protective equipment, especially for the face, respiratory organs and vision, the availability of hygienic hand treatment during work, regular instruction on infectious safety, using interactive forms of training, and the organization of screening examinations of previously unvaccinated and unvaccinated employees.
Relevance In the context of the new coronavirus infection (COVID-19) pandemic, research on the formation of an immune response to SARS-CoV-2 in patients with various clinical forms of this infection is of particular relevance, which is important for understanding the degree of their participation in the formation of population immunity and assessing individual immunity to SARS-CoV-2 in the future. Aim of the study was to analyze the timing of the formation of specific antibodies to SARS-CoV-2 and the duration of their preservation in patients with a new coronavirus infection. Materials and methods. The timing of the formation of specific antibodies of three classes (IgA, IgM and IgG) to SARS-CoV-2 in 218 patients was evaluated in the first days of the disease. Subsequently, they were re-examined at various times from the onset of the disease, from one to four times (a total of 321 control points). To assess the duration of preservation of antibodies to COVID-19 in patients who were ill, a prospective study was organized, in which 368 people participated. Screening for specific class G antibodies was performed every 2–4 weeks, within one to eight months of the onset of clinical manifestations of COVID-19. In total 919 control points. The antibodies were examined by solid-phase enzyme immunoassay using the SARS-CoV-2IgM-ELISA-BEST and SARS-CoV-2-IgG-ELISA-BEST test systems (manufactured by VECTOR-BEST JSC) and Antigma A (manufactured by Generium). Results. In most of the examined individuals, class M and G antibodies began to form from day 10 of the disease, while class A antibodies were detected from day 5. In mild and asymptomatic forms of coronavirus infection, IgG antibodies to SARS-CoV-2 were not formed in most cases, and seroprotection levels correlated with the severity of the disease. The duration of preservation of IgG antibodies could be at least 8 months, but there were isolated cases of their elimination both after COVID-19 in the form of respiratory infection and after interstitial pneumonia. With continuing problems with COVID-19, there were no cases of recurrent disease among individuals who formed G-antibodies (including those who lost them 4-5 months after the disease) during the follow-up period. Conclusion. Thus, according to the results of the study, important materials were obtained on the peculiarities of the formation of a humoral immune response to a new coronavirus infection. However, to fully understand the immune response to SARS-CoV-2, it is necessary to assess the avidity of IgG antibodies or their ability to neutralizing the virus, as well as to study cellular immunity in patients who have had COVID-19 but have not formed antibodies.
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