The Safe Return of Face-to-Face Teaching in the Post-COVID-19 Era at a University in Southern Italy: Surface Monitoring as an Early Warning System

Environmental monitoring for SARS-CoV-2 has become a useful adjunct to clinical testing because it is widely available and relatively inexpensive. During the period May-December 2022 (spring-summer: May-September-autumn: October-December), we assessed the presence and viability of the virus on surfaces in university settings in the Apulia region (Southern Italy) after the resumption of face-to-face teaching activities and evaluated surface monitoring as an early warning system. The sampling plan provided for the selection of 75% of the surface types (e.g., student and teacher desks, computer, handrail) in different materials (plasticized wood, wood, metal, plastic) present in different environments. Overall, 5.4% of surfaces (all students' desks) resulted in positive with RT-PCR and negative with viral culture. Greater contamination was found in the spring-summer period than in the autumn (chi(2) test with Yates correction = 7.6003; p-value = 0.006). The Poisson regression model showed a direct association between the average number of COVID-19 cases among university students in the seven days following sampling and the percentage of SARS-CoV-2 positive swabs on sampling day and (Intercept = 5.32498; beta = 0.01847; p < 0.001). Our results show that environmental monitoring for SARS-CoV-2, especially in crowded settings such as universities, could be a useful tool for early warning, even after the end of the COVID-19 emergency.