'Scuola sicura': a school screening testing programme to prevent the spread of COVID-19 in students in Piedmont.

BACKGROUND: 'Scuola sicura' (SS) programme aims to monitor the rate of COVID-19 and to contain its spread within the school population through early case isolation.

OBJECTIVES: to describe the initial process and outcome evaluation results.

DESIGN: descriptive study of an experimental screening testing programme in children in Piedmont Region (Northern Italy) in the period January-March 2021. The data used came from the COVID-19 platform and the Local Health Units, the archives of birth certificates (CedAP), and hospital discharge files (SDO).

SETTING AND PARTICIPANTS: the screening programme targeted second and third grade students in first level secondary schools. Participants were subdivided into four groups; one group each week underwent screening, yielding one test per student per month.

MAIN OUTCOME MEASURES: it was calculated: 1. number of positive cases detected vs total number of students tested in the SS programme; 2. number of positive cases detected outside the SS program vs. total number of students in the target population. The number of quarantines due to SS and no-SS case identification were detected. To investigate the spread of COVID-19 in households, the mother-child pairs were identified through record linkage between the CedAP and SDO archives, and positive mothers were identified.

RESULTS: sixty-nine percent of schools and 19.5% of the students participated in the programme. SS detected 114 positives cases for SARS-CoV-2. On 08.03.2021, the target classes started distance learning: 69 of the 114 positive students were identified before that date, leading to the activation of 67 quarantine measures. Only for 61 out of 69 of those students (88%) was possible to identify the mother; 46 mothers had performed a swab test after the positivity of their child with a positive result in 11 cases. Asymptomatic cases identified at screening during in-class learning period accounted for 26.5% of the total number of cases occurred in the participating classes.

CONCLUSIONS: this is one of the few studies (and the first in Italy) to describe the functioning and predictive capacity of school screening testing for SARS-CoV-2 in a real-world situation. The findings provide data-driven suggestions for government agencies when planning large-scale school screening testing programmes.