Prevalence of SARS-CoV-2 infection and associated risk factors: A testing program and nested case-control study conducted at Sapienza University of Rome between March and June 2021

Abstract

BackgroundTo safely resume in-person activities during the COVID-19 pandemic, Sapienza University of Rome implemented rigorous infection prevention and control measures, a successful communication campaign and a free SARS-CoV-2 testing program. In this study, we describe the University's experience in carrying out such a program in the context of the COVID-19 response and identify risk factors for infection.MethodsHaving identified resources, space, supplies and staff, from March to June 2021 Sapienza offered to all its enrollees a molecular test service (8.30 AM to 4 PM, Monday to Thursday). A test-negative case-control study was conducted within the program. Participants underwent structured interviews that investigated activity-related exposures in the 2 weeks before testing. Multivariable conditional logistic regression analyses were performed. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were calculated.ResultsA total of 8,959 tests were administered, of which 56 were positive. The detection trend followed regional tendencies. Among 40 cases and 80 controls, multivariable analysis showed that a known exposure to a COVID-19 case increased the likelihood of infection (aOR: 8.39, 95% CI: 2.38–29.54), while having a job decreased it (aOR: 0.23, 95% CI: 0.06–0.88). Of factors that almost reached statistical significance, participation in activities in the university tended to reduce the risk (aOR: 0.32, 95% CI: 0.09–1.06), while attendance at private gatherings showed an increasing risk trend (aOR: 3.48, 95% CI: 0.95–12.79). Age, gender, activities in the community, visiting bars or restaurants, and use of public transportation were not relevant risk factors. When those students regularly attending the university campus were excluded from the analysis, the results were comparable, except that attending activities in the community came close to having a statistically significant effect (aOR: 8.13, 95% CI: 0.91–72.84).ConclusionsThe testing program helped create a safe university environment. Furthermore, promoting preventive behavior and implementing rigorous measures in public places, as was the case in the university setting, contributed to limit the virus transmission.

Keeping university open did not increase the risk of SARS-CoV-2 acquisition: A test negative case-control study among students

“…Our results clearly indicate that students who attended lectures on the university campus were less likely to become infected. This findings, in line with other previous analytic studies performed at Sapienza during the second and third waves of the pandemic in Italy [ 17 , 19 ], could be explained by the numerous preventive measures implemented within the university to encourage safe reopening: 50% reduction in classroom capacity; hybrid face-to-face/at-distance lectures; low occupancy of all indoor spaces (libraries, laboratories, refreshment areas) and enforcement of face-mask wearing within all campus premises. A widespread campaign was enacted by Sapienza University to encourage students to focus on a combined four-part strategy: washing hands, staying at home in case of signs or symptoms suggestive of COVID-19, physical distancing, and continuous mask use [ 46 ].…”

“…More in line with the existing literature is the lack of an association with other social activities, such as shopping [ 4 , 5 , 7 – 9 , 12 ], attending indoor sports activities [ 5 , 7 , 8 , 12 ], and using public transport [ 4 , 5 , 7 ]. Overall these data seem to indicate a minimal risk when visiting places that implement strict preventive measures such as mandatory use of face masks and physical distancing, reduction of maximum capacity, and regulation of access by means of the EU digital COVID certificate [ 4 , 8 , 12 , 15 , 17 , 19 ].…”

“…A test-negative case-control study was conducted between 8 th September 2021 and 3 rd February 2022 during the testing program organized by Sapienza University of Rome, which offered a free RT-PCR (reverse transcriptase polymerase chain reaction) molecular test to all students enrolled in degree programs (2021–2022 academic year) [ 19 ]. Students who confirmed positive for SARS-CoV-2 during the testing program were enrolled as cases.…”

“…After the release of the anti-COVID-19 vaccine, the campaign was modified to include active promotion of vaccination adherence by students and university staff [47]. Additionally, a free SARS-CoV-2 testing program for all asymptomatic students and a surveillance system for SARS-CoV-2 cases among students and university staff were instituted during the early stages of the COVID-19 response [17][18][19], to facilitate the test-trace-isolate-quarantine strategy, activities that may have been particularly useful in contrasting the virus spread in those scenarios with a high virus circulation such as the winter of 2022, during which we registered the highest number of positive cases. Overall, these measures seem contributed to maintaining a safe environment on the campus and may have induced a less risky behavior also outside the university.…”

“…In this context, the identification of risk factors for the transmission of SARS-CoV-2 infection is crucial to guide health policy decisions aimed at limiting virus transmission and, at the same time, preserving the normal activities of everyday life as far as possible [2,3]. However, few analytical epidemiological studies have been conducted worldwide to investigate the risk factors for SARS-CoV-2 acquisition [4][5][6][7][8][9][10][11][12][13], particularly in healthy individuals attending community settings and areas posing unique challenges for transmission control, such as schools [14][15][16] and higher education institutions (HEIs) [17][18][19][20].…”