No abstract

The microbiota of the respiratory tract remains a relatively poorly studied subject. At the same time, like the intestinal microbiota, it is involved in modulating the immune response to infectious agents in the host organism. A causal relationship between the composition of the respiratory microbiota and the likelihood of development and the severity of COVID-19 may be hypothesized. We analyze biomaterial from nasopharyngeal smears from 336 patients with a confirmed diagnosis of COVID-19, selected during the first and second waves of the epidemic in Russia. Sequences from a similar study conducted in Spain were also included in the analysis. We investigated associations between disease severity and microbiota at the level of microbial community (community types) and individual microbes (differentially represented species). To search for associations, we performed multivariate analysis, taking into account comorbidities, type of community and lineage of the virus. We found that two out of six community types are associated with a more severe course of the disease, and one of the community types is characterized by high stability (very similar microbiota profiles in different patients) and low level of lung damage. Differential abundance analysis with respect to comorbidities and community type suggested association of Rothia and Streptococcus genera representatives with more severe lung damage, and Leptotrichia, unclassified Lachnospiraceae and Prevotella with milder forms of the disease.

No abstract

The study involved 271 patients (132 men and 139 women) with moderate COVID-19. Superoxide dismutase (SOD) activity in erythrocytes was measured spectrophotometrically. In total group of patients (divided into age groups of 18-35, 36-45, 46-60, and 61-90 years), higher SOD activity was found in the 18-35 age group in comparison with the groups 46-60 years ( p <0.01) and 61-90 years ( p <0.05). Then, the groups were additionally divided by sex. In men, no differences in enzyme activity were found between the age groups. In women of early reproductive age, SOD activity was higher than in groups 36-45, 46-60, and 61-90 years. The sex differences consisted in higher SOD activity in women aged 18-35 years in comparison with men of this age. These data should be taken into account when choosing the tactics of therapy for patients with moderate COVID-19 course.

РезюмеЦель: изучение отношения к вакцинации врачей разных специальностей г. Иркутска.Материалы и методы. По данным кросс-секционного описательного многоцентрового исследования проведена оценка информированности в вопросах вакцинопрофилактики 324 врачей разных специальностей. Из указанной выборки респондентов были выделены 3 группы: группа 1 (n = 218) -врачи, назначающие вакцинацию детям (педиатры, неонатологи); группа 2 (n = 54) -врачи, назначающие вакцинацию взрослым (терапевты, акушеры-гинекологи); группа 3 (n = 52) -врачи, которые могут консультировать по вопросам вакцинации (неврологи, хирурги и другие специалисты). Статистический анализ результатов проведён с использованием программы «Statistica 6.0». Критический уровень значимости при проверке статистических гипотез о существовании различий показателей между группами p принят равным 0,05.

Objective. To determine the most general patterns of the clinical and laboratory course of seasonal influenza in children with obesity compared with normal weight children. Patients and methods. A retrospective comparative study of 117 medical records of children with influenza admitted from 2016 to 2019 to the Regional Infectious Diseases Hospital was conducted. The study included two groups of children with seasonal influenza: children with obesity (cases, n = 36) and children with normal weight (controls, n = 81). Nasopharyngeal swabs were tested for influenza and other common respiratory pathogens by PCR. A comparative analysis of structure, prevalence and duration of main clinical symptoms and syndromes, occurrence of influenza complications, data of laboratory general, biochemical and instrumental methods of examination in children with and without obesity was carried out. Results. A prevalence of type A influenza virus (H1N1 sw2009) in all children regardless their body weight status was detected. Children with obesity were admitted to the hospital from out-patient department faster (p < 0.005), duration of their hospitalization were longer (p < 0.005). They had higher frequency of pneumonia (p > 0.05), ketoacidosis (p < 0.001). Intravenous maintenance fluid therapy was ordered more often in patients with obesity (p < 0.03). Hematologic factors of blood in children with obesity were defined by significantly higher level of erythrocyte sedimentation rate (p = 0.0006) and platelet level (p = 0.0032). Conclusion. Obesity is considered as an unfavorable factor which aggravates the course of influenza in children. Higher probability of complications in children with obesity and overweight defines the importance of development of additional approaches to the therapy and prevention of acute respiratory diseases in children. Key words: children, clinical symptoms, influenza, obesity, retrospective study

Last year the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has started. The new coronavirus is highly contagious and causes severe complications. The mechanisms of humoral immunity and kinetics of SARS-CoV-2 specific antibodies in a population are not well understood. Therefore, we aimed to summarize and analyze numerous global and Russian serological studies for understanding dynamics of the SARSCoV-2 humoral immune response and getting an accurate picture of the seroprevalence to SARS-CoV-2 in the world population. The PubMed and e-library databases were searched from February 2020 to March 2021 using terms “SARSCoV-2”, “antibodies”, “humoral immunity”. At the beginning of the pandemic first studies were cross-sectional by design and were responsible for determination of the seropositivity and for understanding the fundamental humoral immunity parameters of SARS-CoV-2. Since then, longitudinal seroepidemiological studies have been studying antibody kinetics. Seroconversion time for IgM, IgG antibodies varies, but most researchers report the seroconversion of IgM from the 1st to 14th days after the onset of clinical manifestations, and the seroconversion for IgG is around the 14th day with a concentration peak by the 21st day. Regarding seroprevalence we may say about low herd immunity at the COVID-19 pandemic. Thus, global seroprevalence is about 10 %, and more than 20 % for regions with high incidence and among healthcare workers. Seroprevalence studies have to be continued for more accurate monitoring of long-term humoral immunity to SARS-CoV-2, because the majority of the world’s population is still susceptible to SARS-CoV-2 infection.

No abstract