Dynamics of humoral response to coronavirus antigens among employees of a designated COVID­19 hospital: an observational study.

INTRODUCTION: During the COVID­19 pandemic studies on workplace safety of hospital staff taking care of patients with this disease are a high priority. We decided to analyze the results of opportunistic screening for anti-SARS­CoV-2 antibodies among employees of a designated COVID-19 center. OBJECTIVES: The aim of the study was to investigate whether potential exposition to SARS­CoV-2 antigens is reflected in the results of serological studies. PATIENTS AND METHODS: Every employee who performed at least a single test between April 21 and July 20, 2020 was included in the study. The tests assessed the levels of immunoglobulin (Ig) G and IgM+IgA. Employees working in direct contact with COVID­19 patients and those participating in aerosol­generating procedures were identified. RESULTS: The results of 2455 tests taken by 1572 employees were analyzed. A total of 357 participants (22.7%) had at least 1 positive or equivocal result during the study period. Linear mixed models revealed gradual increases in mean levels of both IgG and IgM+IgA antibodies among employees with all negative results. The rate of change was higher among persons who had direct contact with COVID­19 patients and the highest rate of change was observed among individuals participating in aerosol­generating procedures. CONCLUSIONS: We detected developing humoral immune response to a new set of coronavirus antigens among the study group. It is possible that employees of designated COVID­19 centers are regularly exposed to noninfectious doses of SARS­CoV-2 or its antigens.

Clinical characteristics and short-term outcomes of patients with coronavirus disease 2019: a retrospective single-center experience of a designated hospital in Poland.

INTRODUCTION: Since the first reported case of coronavirus disease 2019 (COVID­19) in Poland, the worldwide pandemic has spread throughout the country, leading to many hospital admissions. There has been an urgent need to determine clinical characteristics of Polish patients with laboratory­confirmed severe acute respiratory syndrome coronavirus 2 (SARS­CoV 2) infection in the clinical setting. OBJECTIVES: The aim of this retrospective study was to outline characteristics and short­ term outcomes of SARS­CoV­2-positive patients. PATIENTS AND METHODS: We retrospectively assessed 169 consecutive patients with laboratory­ confirmed COVID­ 19 with regard to their clinical manifestations, radiological findings, treatment, complications, and outcomes. RESULTS: Of the 169 patients, more than half was aged 65 years or older (88; 52.1%), 51.5% were male, and 78.3% had comorbidities. The majority of patients (106; 62.7%) were transferred from outbreak locations in medical facilities. The most common symptoms on admission were fever (42%), shortness of breath (35%), and fatigue (33%). Twenty seven (15.4%) patients required intensive care unit admission. Overall mortality was 26.3% (n = 46) and was significantly higher in patients transferred from other facilities (38 out of 106; 35.8%), than in patients admitted directly to the hospital (8 out of 63; 12.69%; P <0.001). Seventeen out of 29 patients admitted to the intensive care unit died (mortality, 58.6%), including 30 out of 41 patients with acute respiratory distress syndrome (73.2% mortality rate). CONCLUSIONS: Polish patients with COVID­19 have similar characteristics and risk factors for adverse outcomes to those observed in countries in which outbreaks occurred earlier. Significantly higher mortality in patients transferred from other centers warrants special attention and transfer policy should be verified.