However, the vast majority of the population has not been infected. settings. value less than 0.05. For all those tests, a statement of statistical significance implies a values less than 0.05. Kojic acid Results IgG anti-SARS-CoV-2 immunoassay During the four-week screening period a total of 8679 individuals (77% women and 23% men) participated in the study. All blood samples were analysed for IgG anti-SARS-CoV-2, with 577 (6.6%) positive results using the manufacturers cut-off at 1.4?S/C. Antibody levels were distributed into two populations with a geometrically neutral cut-off at approximately 1.0?S/C (Physique 1). This is in line with a borderline result category recently launched in clinical use between 0.9 and 1.39?S/C, which would expand the seropositive populace to 635 (7.3%) subjects. Open in a separate window Physique 1. Density plot illustrating DCN the distribution of IgG anti-SARS-CoV-2. All values shifted 0.01 to allow logarithmic transformation. All subjects included in the analysis. Baseline characteristics and subgroup prevalence IgG positive study subjects were slightly more youthful and more often working at an inpatient care Kojic acid unit, compared to IgG unfavorable subjects. Evaluation of the unadjusted subgroup prevalence of IgG anti-SARS-CoV-2 seropositive subjects shows higher proportions of IgG positive subjects among male participants and those working in inpatient care models and Covid-19 specific units (Table 1; Physique 2). Open in a separate window Physique 2. Forest plot of IgG anti-SARS-CoV-2 prevalence. Subgroup prevalence and confidence intervals of IgG anti-SARS-CoV-2 positivity. N is the total number of subjects in each category. All subjects included in the analysis. Table 1. Characteristics of IgG anti-SARS-CoV-2 positive and negative study subjects. ValueValue /th /thead Age at sampling, years0.9880.980C0.9950.001Time from study start, days1.0191.004C1.0350.014Male sex1.1070.879C1.3940.387Working in primary health care0.7110.493C1.0260.068Working with outpatient care0.6310.497C0.801 0.001Working in Covid-19 specific unit1.1140.766C1.6190.572Working in Covid-19 Kojic acid possible unit1.2750.945C1.7210.112 Open in a separate window Multivariable logistic regression model. Only healthcare staff included in the analysis. Conversation The Covid-19 pandemic has put healthcare systems across the world at stress, to an extent that has rarely been seen in developed countries. In Sweden, the just-in-time logistics system for delivering personal protective gear failed within days to weeks when the demand quickly increased to a level that was beyond Kojic acid the imagination of the regional pandemic planning in early 2020 (10). Given that staff availability and experience are key to healthcare capacity and quality, protecting healthcare professionals from hospital-acquired infections is pivotal. In contrast to early reports of numerous cases of severe infections and deaths among Chinese and Italian healthcare Kojic acid professionals (3,4), the overall rate of IgG anti-SARS-CoV-2 in our study is usually relatively low. However, our analyses show that healthcare workers at inpatient care units have a statistically significantly increased risk of contamination that cannot be explained by demographic differences or transmission at Covid-19 specific care units only. The age-dependent association likely represents two factors, both a higher level of community transmission among the young, and a correlation between age and level of physical contact with patients during inpatient care, which relates to differences in length of training and the pyramid-shaped age-related hierarchy among different categories of clinical staff. Our findings emphasize the need for a high standard in basic hygiene routines in all settings, especially in inpatient care where physical contact with patients is usually more.