The sensitivity and specificity of the test were 98% and 100%, respectively, nine days after symptom onset in patients with confirmed SARS-CoV-2 infection. seropositive using the spike RBD assay; four (0.4%) were seropositive using the nucleocapsid assay, and 44 (4.8%) using the Spike NTD assay. Cumulative incidence was 3.61% (95% CI: 2.04C5.16). Six asymptomatic individuals experienced positive RT-PCR results. Conclusions Prevalence and incidence of SARS-CoV-2 infections were low; however, variations in target antigens of serological checks provided different estimations. Long term study on appropriate methods of serological screening in unvaccinated and vaccinated populations is needed. Frequent RT-PCR screening of asymptomatic individuals is required to detect acute infections, and repeated serosurveys are beneficial for monitoring subclinical illness. Intro The SARS-CoV-2 pandemic caused significant SB-222200 disruptions to research programs across university or college campuses. In March of 2020, most experts, support staff, and trainees were sent home as nonessential study activities SB-222200 were halted. Super-spreader events early in the pandemic experienced engendered concern about the security of working in person due to the possibility of asymptomatic infections among individuals and the potential for spread of COVID-19 within the place of work [1, 2]. Therefore, only essential study staff remained on campus throughout the early months of the pandemic. However, beginning in mid-2020, many universities started bringing study staff back to campuses following new security protocols, with different approaches to screening for SARS-CoV-2 to identify infections in the workplace. Approximately 30% of unvaccinated individuals are estimated to have asymptomatic illness with SARS-CoV-2 [3], and asymptomatic individuals may account for approximately 25% of transmissions [4]. Individuals with asymptomatic illness appear to harbor related viral load levels to the people of symptomatic individuals. However, asymptomatic individuals are likely to shed for fewer days than symptomatic individuals [5]. Shorter duration of viral dropping may SB-222200 have implications for the effectiveness of regular SARS-CoV-2 screening strategies to detect acute infections among asymptomatic individuals in the workplace. Furthermore, pre-symptomatic individuals are known to be infectious, with viral dropping shown 48 hours prior to sign onset [6]. The primary objective of this study was to describe the extent of SARS-CoV-2 seroprevalence and incidence among the research community at an academic university or college from July to December 2020. Methods Eligibility and recruitment We carried out a longitudinal cohort study of study faculty, staff, and students who have been coming to the University or college of North Carolina at Chapel Hill (UNC-CH) campus at least one day per week between July and December 2020. Employees or college students Comp who carried out or supported study activities, reported coming to campus at least one day a week, and were age 18 or older were eligible to enroll. All individuals who received funding from research grants were invited to participate. Over 5,000 individuals were SB-222200 identified as receiving funding from study grants and invited to participate in the study; in addition, support staff coming to campus were recruited via email and fliers on campus. Testing and enrollment took place online via a REDCap survey. Consent was provided electronically. After enrollment, the study team scheduled the participant for an in-person visit. The day time before the visit, the participant received an invitation to total an online questionnaire and was assessed for symptoms of SARS-CoV-2. Anyone with symptoms was instructed to call their healthcare provider, follow UNC-CH recommendations for COVID-19 screening, and to re-schedule their study check out. On the day of the check out, screening methods for COVID-19 were repeated. Participants who also enrolled in.