No abstract

An excessive inflammatory response to SARS-CoV-2 is thought to be a major cause of disease severity and mortality in patients with COVID-19. Longitudinal analysis of cytokine release can expand our understanding of the initial stages of disease development and help to identify early markers serving as predictors of disease severity. In this study, we performed a comprehensive analysis of 46 cytokines (including chemokines and growth factors) in the peripheral blood of a large cohort of COVID-19 patients (n=444). The patients were classified into five severity groups. Longitudinal analysis of all patients revealed two groups of cytokines, characterizing the “early” and “late” stages of the disease course and the switch between type 1 and type 2 immunity. We found significantly increased levels of cytokines associated with different severities of COVID-19, and levels of some cytokines were significantly higher during the first three days from symptom onset (DfSO) in patients who eventually required intensive care unit (ICU) therapy. Additionally, we identified nine cytokines, TNF-α, IL-10, MIG, IL-6, IP-10, M-CSF, G-CSF, GM-CSF, and IFN-α2, that can be used as good predictors of ICU requirement at 4-6 DfSO.

The avidity index (AI) of IgG to the RBD of SARS-CoV-2 was determined for 71 patients with a mild (outpatient) course of COVID-19, including 39 primarily and 36 secondarily reinfected, and 92 patients with a severe (hospital) course of COVID-19, including 82 primarily and 10 secondarily infected. The AI was shown to correlate with the severity of repeated disease. In the group of outpatients with a mild course, the reinfected patients had significantly higher median AIs than those with primary infections (82.3% vs. 37.1%, p < 0.0001). At the same time, in patients with a severe course of COVID-19, reinfected patients still had low-avidity antibodies (median AI of 28.4% vs. 25% in the primarily infected, difference not significant, p > 0.05). This suggests that the presence of low-avidity IgG to RBD during reinfection is a negative prognostic factor, in which a patient’s risk of developing COVID-19 in a severe form is significantly increased. Thus, patients with IgG of low avidity (AI ≤ 40%) had an 89 ± 20.5% chance of a severe course of recurrent COVID-19, whereas the detection of high-avidity antibodies (AI ≥ 50%) gave a probability of 94 ± 7.9% for a mild course of recurrent disease (p < 0.05).

No abstract

The ongoing worldwide COVID-19 pandemic caused by SARS-CoV-2 has had serious impacts on not only the health care system but also all sectors of the economy. Thanks to the adoption of various epidemiological measures, a significant reduction in new cases of infection has been achieved. However, there are still "hotspots", such as healthcare settings focused on treating patients with COVID-19, which are characterized by the risk of nosocomial transmission among health care workers, patients, and visitors. The proper monitoring and timely detection of pathogens in a hospital environment will help prevent further spread of coronavirus infection. In this study, we collected samples from the air and surface swabs at the First Moscow Infectious Diseases Hospital to study the spread of the SARS-CoV-2 in various hospital locations. More than 130 aerosol and surface samples were collected and analysed by RT-PCR. We detected viral contamination of the air in the intensive care unit (ICU) but not in the respiratory infection department where less severe patients are treated. The concentration of SARS-CoV-2 RNA was low, consisting of less than one copy per litre of air. The contact surfaces in both departments were contaminated with SARS-CoV-2. Considering the possible transmission of SARS-CoV-2 through fomites, these results indicate the need to strictly follow personal hygiene rules as well as wear personal protective equipment to prevent disease spread.