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ContextOn March 11, the World Health Organization (WHO) announced the current corona virus disease 2019 (COVID-19) outbreak as a pandemic. The first laboratory-confirmed case of COVID-19 in Austria was announced on February 27, 2020. Since then, the incidence of infection followed an exponential increase until a complete lockdown in March 2020. Thereafter easing of restrictions was gradually introduced and until mid-August daily infections remained mostly below 5 per 100.000 population. ObjectivesThe aims of this study are to determine i) how many employees in Austrian trauma hospitals and rehabilitation facilities have virus specific IgG and IgM, and/or neutralizing antibodies against SARS-CoV-2, ii) how many are active virus carriers (symptomatic and asymptomatic) during the study, iii) the antibody decline in seropositive subjects over a period of around six months, and iv) the utility of rapid antibody tests for outpatient screening. Study DesignOpen uncontrolled observational cross-sectional study. Setting/ParticipantsA total of 3301 employees in 11 Austrian trauma hospitals and rehabilitation facilities of the Austrian Social Insurance for Occupational Risks (AUVA) participated in the study. Study Interventions and MeasuresRapid antibody tests for SARS-CoV-2 specific IgG and IgM antibodies, and RT-PCR tests based on oropharyngeal swab samples, as well as laboratory-based antibody tests using ELISA/PRNT were performed. The tests were conducted twice, with an interval of 42.4{+/-}7.7 (Min=30, Max=64) days. Additionally, participants filled out a questionnaire including questions related to personal health, traveling activities, living situation, as well as inquiries of symptoms and comorbidities. Antibody positive tested participants were re-tested with ELISA/PRNT tests at a third time point on average 188.0{+/-}12.8 days after their initial test. ResultsIn our study cohort, only 27 out of 3301 participants (0.81%) had a positive antibody test at any time point during the study confirmed via neutralization test. Among participants who had positive test results in either of the antibody tests, 50.4% did not report any symptoms consistent with common manifestations of COVID-19 during the study period or within the preceding six weeks. In the group who tested positive during or prior to study inclusion the most common symptoms of an acute viral illness were rhinitis (21.9%), and loss of taste and olfactory sense (21.9%). The rapid antibody test was generally more sensitive based on serum (sensitivity=86.6%) as compared to whole blood (sensitivity=65.4). Concerning both ELISA tests overall the Roche test detected 24 (sensitivity=88.9%) and the Diasorin test 22 positive participants (sensitivity=81.5%). In participants with a positive PRNT, a significant decrease in PRNT concentration from 31.8{+/-}22.9 (Md=32.0) at T1 to 26.1{+/-}17.6 (Md=21.3) at T2 to 21.4{+/-}13.4 (Md=16.0) at T3 ({chi}2=23.848, df=2, p<0.001) was observed ({chi}2=23.848, df=2, p<0.001) - with an average time of 42.4{+/-}7.7 days between T1 and T2 and 146.9{+/-}13.8 days between T2 and T3. ConclusionsDuring the study period (May 11th - December 21th) only 0.81% were tested positive for antibodies in our study cohort. The antibody concentration decreases significantly over time with 14.8% (4 out of 27) losing detectable antibodies.
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<p><b>PURPOSE</b>It has been suggested that patients with traumatic insults are resuscitated into a state of an early systemic inflammatory response. We aimed to evaluate the influence of hemorrhagic shock and resuscitation (HSR) upon the inflammatory response capacity assessed by overall TNF-α secretion capacity of the host compared to its release from circulating leukocytes in peripheral circulation.</p><p><b>METHODS</b>Rats (8/group) subjected to HS (MAP of 30-35 mmHg for 90 min followed by resuscitation over 50 min) were challenged with Lipopolysaccharide (LPS), 1 μg/kg intravenously at the end of resuscitation (HSR-LPS group) or 24 h later (HSR-LPS24 group). Control animals were injected with LPS without bleeding (LPS group). Plasma TNF-α was measured at 90 min after the LPS challenge. In addition, whole blood (WB) was obtained either from healthy controls (CON) immediately after resuscitation (HSR), or at 24 h post-shock (HSR 24). WB was incubated with LPS (100 ng/mL) for 2 h at 37 °C. TNF-α concentration and LPS binding capacity (LBC) was determined.</p><p><b>RESULTS</b>Compared to LPS group, HSR followed by LPS challenge resulted in suppression of plasma TNF-α in HSR-LPS and HSR-LPS24 groups (1835 ± 478, 273 ± 77, 498 ± 200 pg/mL, respectively). Compared to CON the LPS-induced TNF-α release capacity of circulating leukocytes ex vivo was strongly declined both at the end of resuscitation (HSR) and 24 h later (HSR24) (1012 ± 259, 313 ± 154, 177 ± 63 ng TNF/mL, respectively). The LBC in WB was similar between CON and HSR and only moderately enhanced in HSR24 (57 ± 6, 56 ± 6, 71 ± 5 %, respectively).</p><p><b>CONCLUSION</b>Our data suggest that the overall inflammatory response capacity is decreased immediately after HSR, persisting up to 24 h, and is independent of LBC.</p>