Monitoring of SARS-CoV-2 circulation using saliva testing in school children in Rome, Italy.

• Saliva testing is useful in community mass-screening programs. • Circulation of SARS-CoV-2 is low in primary and lower secondary schools in Rome. • Low circulation suggests a relatively low risk of being infected at school. • Similar trends of positivity are found in students' saliva and local surveillance unit RM3 population's nasopharyngeal swabs. • Screening in the schools allows monitoring of SARS-CoV-2 circulation. To describe the trend of SARS-CoV-2 RNA in saliva samples from children attending nine schools in Rome in the local surveillance unit RM3 during the period of September 2021-March 2022, in parallel with the trend of SARS-CoV-2 RNA observed in nasopharyngeal swabs (NPSs) from the population in the same catchment area that was routinely tested at our laboratory in the same period. Saliva samples were collected using the Copan LolliSpongeTM device and analyzed by Aptima® SARS-CoV-2 Assay on the Panther® System. NPSs were tested using either Aptima® SARS-CoV-2 Assay or Alinity m SARS-CoV-2 Assay. The percentage of positivity in the two populations was different; of the 2222 saliva samples from students, 0.99% had positive results, whereas the percentage was higher (33.43%) in the 8994 NPSs representing the population from local surveillance unit RM3. Interestingly, the trend of SARS-CoV-2 RNA in saliva samples from students was consistent with that observed in NPSs from the population in same catchment area, although with peaks slightly anticipated. Overall, screening of saliva in the schools represents a good system to monitor SARS-CoV-2 circulation in the population, allowing early detection and quick isolation of students who are asymptomatic with positive test results and thus prevention of virus transmission. [ABSTRACT FROM AUTHOR]