The value of rapid antigen tests for identifying carriers of viable sars-cov-2

The search for effective methods to detect patients who excrete a viable virus is one of the urgent tasks of modern biomedicine. In the present study, we examined the diagnostic value of two antigen tests, BIOCREDIT COVID-19 Ag (RapiGEN Inc., Anyang, Korea) and SGTI-flex COVID-19 Ag (Sugentech Inc., Cheongju, Korea), for their diagnostic value in identifying patients who excrete viable SARS-CoV-2. As part of the study, we examined samples from 106 patients who had just been admitted to the hospital and who had undergone quantitative RT-PCR and assessment of vi-ability of SARS-CoV-2 using cell culture. Assessment of the tests’ value for detecting samples containing viable virus showed high sensitivity for both tests. Sensitivity was 78.6% (95% CI, from 49.2% to 95.3%) for SGTI-flex COVID-19 Ag and 100% (95% CI, from 76.8% to 100%) for Biocredit COVID-19 Ag. The specificity of rapid tests was significantly higher than that of RT-PCR and was 66.3% (95% CI, from 55.7% to 75.8%) and 67.4% (95% CI, from 56.8% to 76.8%) for SGTI-flex COVID-19 Ag and Biocredit COVID-19 Ag versus 30.4% (95% CI, from 21.3% to 40.9%) obtained for PCR. Thus, for tasks of identifying viable SARS-CoV-2 during screening of conditionally healthy people, as well as monitoring those quarantined, rapid tests show significantly better results. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

ASSESSMENT OF COVID-19 CLINICAL COURSE IN PATIENTS VACCINATED WITH SPITNIK V, SARS-COV-2 S PROTEIN RBD DOMAIN VARIATION AND SERUM VIRUS NEUTRALIZING ACTIVITY

The COVID-19-associated mortality remains high. Studying the features of the COVID-19 course in vaccinated patients, who have got ill on different dates after vaccination, compared to unvaccinated individuals is relevant. The study was aimed to assess clinical and immunological features of the COVID-19 course, as well as to assess humoral immunity (virus neutralizing activity, VNA) and SARS-CoV-2 S protein RBD domain variation in the groups of patients, previously vaccinated with Sputnik V, and unvaccinated patients. A total of 251 patients with confirmed diagnosis of COVID-19 were enrolled, of them 116 individuals were previously vaccinated with one or two Sputnik V vaccine components, and 135 patients were not vaccinated (comparison group). Individuals over 50 years of age prevailed (82.8%). The patients, who received two vaccine components, had mild to moderate COVID-19 (92.1%). In the group of unvaccinated patients, 11 individuals received treatment in the ICU, 10 of them died. The viral load was significantly lower in vaccinated patients. Mutations of SARS-CoV-2, such as S477N, S477N+A522S, E484K and E484K+S494P, were identified both in vaccinated and unvaccinated patients. Assessment of the neutralizing activity of sera revealed no significant differences in VNA against different variants of SARS-CoV-2 mutations. The data obtained demonstrate that the lack of vaccination is an aggravating factor and is capable of increasing the risk of severe course and death in patients with COVID-19

Clinical and laboratory profile of patients with COVID-19 admitted to hospital in Moscow between may and july 2020

Objective. Data of the clinical picture forms of the disease, management and diagnostic capabilities of patients with COVID-19 continue to be studied. Our study presents results from the analysis of clinical and laboratory parameters of patients with COVID-19 in the period May-June 2020, who were treated in an infectious diseases hospital in Moscow. Patients and methods. The analytical cohort included 444, 198 men, 246 women aged 18 to 95 years, who were identified with SARS-CoV-2 RNA. The severity of the disease was determined in accordance with the temporary clinical recommendations (version 6 effective April 28, 2020), NEWS. Results. The study of the clinical picture showed the variability of the spectrum of clinical manifestations of COVID-19. The most common symptoms were fever, weakness, myalgia, dry cough, shortness of breath, diarrhea. The severity of the infection was not associated with the patient's gender, but was significantly correlated with age and the presence of comorbid status, which included chronic lung diseases, obesity, diabetes mellitus, and cardiovascular diseases. Observations of patients with severe and extremely severe course revealed characteristic laboratory markers of severity. The main method of etiological diagnosis was the RT-PCR method for detecting SARS-CoV-2 RNA in the nasopharyngeal secret. To verify COVID-19, we used an additional PCR method, fecal testing for the detection of SARS-CoV-2 RNA. © 2021, Dynasty Publishing House. All rights reserved