Finally, the idea of high-risk contact seemed better to identify in the professional setting than in the private setting as well as the identification of high-risk contact was easier through the second wave in both configurations. The COVID-19 pandemic is arguably the main and rapidly evolving infectious public ailment in the world because the AIDS pandemic, and worldwide efforts are created to suppress or eliminate its spread you should including hand hygiene, social distancing, early screening, analysis, and quarantine [15,16]. in HCWs inside our hospital following the 1st and second pandemic waves also to characterize the distribution of the seroprevalence with regards to different criteria. Strategies: By the end of both recruitment periods, a complete of 3-Hydroxydecanoic acid 4008 serological testing were performed with this single-center cross-sectional research. After completing a questionnaire including personal and demographic data, possible earlier COVID-19 diagnostic test outcomes and/or the current presence of symptoms potentially linked to COVID-19, the analysis individuals underwent bloodstream sampling and serological tests using DiaSorins LIAISON? SARS-CoV-2 S1/S2 IgG test for the first phase and LIAISON? SARS-CoV-2 TrimericS IgG test for the second phase of this study. Results: In total, 302 study participants (10.72%) in the first round of the study and 404 (33.92%) in the second round were positive for SARS-CoV-2-IgG antibodies. The prevalence of seropositivity observed after the second wave was 3.16 times higher than after the first wave. We confirmed that direct, prolonged, and repeated contact with patients or their environment was a predominant seroconversion factor, but more unexpectedly, that this was the case Rabbit polyclonal to Rex1 for all HCWs and not only caregivers. Finally, the notion of high-risk contact seemed more readily identifiable in ones workplace than in ones private life. Conclusions: Our study confirmed that HCWs are at a significantly higher risk of contracting COVID-19 than the general population, and suggests that repeated contacts with at-risk patients, regardless of the HCWs professions, represents the most important risk factor for seroconversion (Clinicaltrials.gov number, “type”:”clinical-trial”,”attrs”:”text”:”NCT04723290″,”term_id”:”NCT04723290″NCT04723290). 0.01). Thus, even though DiaSorins new kit significantly decreases the positivity rate by a factor of 0.954, it does not significantly affect the comparison of the seroconversion rates of our study population between the two phases. Thus, even though DiaSorins new kit purportedly offers an improved detection of IgG neutralizing antibodies, it does not significantly alter the seroconversion rate of our study population in the second phase. Consent forms, participant information, questionnaires, and test requests were centralized via a highly secure IT platform to ensure data confidentiality throughout the process. The procedure for healthcare workers who tested positive for SARS-CoV-2 between 20 June and 11 August 2020 and during 6 February to 31 March 2021 followed the Belgian guidelines (Sciensano.be). During the first period, they were isolated for at least 7 days at home and for at least 10 days during the second period due to the Delta COVID-19 variant. Return to work was allowed on the condition that there was no fever for at least 3 days and that there was an improvement in the respiratory symptoms. The descriptive statistical evaluation of the questionnaire data, correlated with the laboratory results, used the following methods as appropriate: computation of the 95% confidence limits for proportions using the Wilson method [13] and uncorrected Pearsons Chi2 test for comparing proportions in independent samples (with two-tailed probability) [14]. The study protocol was fully approved by the hospitals independent 3-Hydroxydecanoic acid ethics committee and the Clinicaltrials.gov Identifier is “type”:”clinical-trial”,”attrs”:”text”:”NCT04723290″,”term_id”:”NCT04723290″NCT04723290. 3. Results For the first phase of the study, from 20 June to 11 August 2020, 3474 HCWs expressed their interest and filled out the informed consent form but finally, only 2817 of them came to be serologically tested. During the second phase of the study, from 6 February to 31 March 2021, 1191 HCWs were serologically tested. Thus, over both rounds of this study, we collected 4008 serology results for further analysis. Table 1 presents the distribution of the participants by gender, 3-Hydroxydecanoic acid age, and profession category within the hospital for each round. During the first phase of this study, the gender distribution of our sample was 2293 females (81.4%) and 524 males (18.6%) and perfectly matched that of the general hospital staff, i.e., 3201 females (82%) and 693 males (18%). That.