RESUMO
Objective: To examine how in-person classroom instruction was related to risk of SARS-CoV-2 infection in undergraduate students. Participants: Indiana University undergraduate students (n = 69,606) enrolled in Fall 2020, when courses with in-person and remote instruction options were available. Methods: Students participated weekly in mandatory SARS-CoV-2 RT-PCR asymptomatic testing by random selection, supplemented with symptomatic testing as needed. We used log-binomial regression models to estimate the association between number of in-person credit hours and the risk of SARS-CoV-2 infection over the course of the semester. Results: Overall 5,786 SARS-CoV-2 cases were observed. Increased in-person credit hour exposures were not associated with increased risk of SARS-CoV-2 overall [aRR (95% CI): 0.98 (0.97,0.99)], nor within specific subgroups (Greek affiliation and class). Conclusions: In-person instruction did not appear to increase SARS-CoV-2 transmission in a university setting with rigorous protective measures in place, prior to mass vaccine rollout and prior to delta variant emergence.
RESUMO
The aim of this study is to compare the COVID-19 nasopharyngeal PCR (NP PCR) to antigen, nasal PCR, and viral culture. One-hundred-and-fourteen risk-stratified patients were tested by culture, nasal PCR, NP PCR, and Ag testing. Twenty (48%) of the high risk and 23 (32%) of the low risk were NP PCR positive. Compared with NP PCR, the sensitivity of nasal PCR, Sofia Ag, BinaxNOW Ag, and culture were 44%, 31%, 37%, and 15%. In the high risk group, the sensitivity of these tests improved to 71%, 37%, 50%, and 22%. Agreement between tests was highest between nasal PCR and both antigen tests. Patients who were NP PCR positive but antigen negative were more likely to have remote prior COVID-19 infection (p<0.01). Nasal PCR and antigen positive patients were more likely to have symptoms (p = 0.01).
