Pre-Vaccination Anti-Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Seroprevalence in Workers at Three Japanese Hospitals.

BACKGROUND: Antibody testing is essential for accurately estimating the number of people infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to investigate the influence of background factors on seroprevalence by testing for anti-SARS-CoV-2 antibodies in blood samples obtained from the staff of three hospitals. METHODS: This cross-sectional observational study was conducted from June 8 to July 4, 2020, as part of a mandatory health examination. Leftover blood samples collected during the health examinations at each hospital were used to test for the presence of anti-SARS-CoV-2 antibodies. The Elecsys Anti-SARS-CoV-2 RUO assay was used for antibody detection. The relationship between staff age, gender, body mass index, blood pressure, work environments with different exposure risks, place of residence, and campus location and seroprevalence was investigated. The data were anonymized prior to analysis. RESULTS: A total of 3,677 individuals were included in the study, comprising 2,554 females (69.5%) and 1,123 males (30.5%). Anti-SARS-CoV-2 antibody (immunoglobulin G) was detected in 13 participants (0.35%). Seroprevalence was slightly higher in males than females (0.62% vs. 0.23%, P=0.08). By occupation, anti-SARS-CoV-2 antibodies were found in 6 (0.75%) physicians, 6 (0.31%) nurses, and one individual (0.11%) in the medical personnel group, with slightly higher levels in physicians. No significant difference was noted in the seroprevalence in terms of all background factors. CONCLUSIONS: Our study shows that the background factors do not impact seropositivity rates. Thorough daily infection control and adherence to recommended health guidelines were found to reduce infection risk.

[Significant Prolongation of the International Normalized Ratio Associated with COVID-19 Treatment: Possible Drug Interaction with Remdesivir].

A 55-year-old man with hypertrophic cardiomyopathy and a pacemaker was admitted with coronavirus disease 2019 (COVID-19). Before admission, the patient's medications included amiodarone, diltiazem, bisoprolol, atorvastatin, etizolam, and warfarin (WF). After admission, dexamethasone (DXM) and remdesivir (RDV) were initiated for treating COVID-19. The international normalized ratio (INR) on admission was 1.8, which increased to 3.4 on day 5 and to 6.9 on day 10 after admission. Although there have been reports that RDV may occasionally prolong prothrombin time and that the degree of prolongation is often less severe, the mechanism of action has not been elucidated till date. There are reports of prolonged INR when WF is co-administered with RDV and DXM, suggesting that drug interactions may be a potential cause for the prolongation. A similar drug interaction may have potentially occurred in the case reported here. In addition, this case used amiodarone (AMD), and it has been reported that the RDV concentration increases when used in combination with AMD. Further investigations are needed to elucidate the cause of INR prolongation. Thus, close monitoring of the patient is recommended when RDV is co-administered with high-risk agents to avoid unnecessary side effects.