We report epidemiological investigations of transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 41 classes of 36 schools in Reggio Emilia province, northern Italy, from their reopening on 1 September to 15 October 2020. The overall secondary case attack rate was 3.2%, reaching 6.6% in middle and high schools. More timely isolation and testing of classmates could be effective in reducing virus transmission in this setting.

BackgroundSchool closures was one of the main measures undertaken to reduce the number of social contacts during the first wave of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. We aimed to describe the data on secondary transmission of SARS-CoV-2 among students and teachers/personnel after the reopening of preschools and schools in Reggio Emilia, Italy.MethodsThis prospective population-based study included all consecutive cases leading to an investigation in 41 classes of 36 educational institutions (8 infant-toddler centres and preschools, 10 primary and 18 secondary schools) in the period September 1 – October 15, 2020, in Reggio Emilia province, Italy. We report the characteristics of the school, of the index case, including the possible source of infection, the number of contacts (students and teachers/personnel) that were identified and tested and the characteristics of secondary cases.ResultsIn the study period, 994 students and 204 teachers were tested during related investigations due to notification of 43 primary cases (38 among students and 5 among teachers). Of these, 10 students and two teachers created 39 secondary cases, resulting in an attack rate of 3.9%. There were no secondary cases among teachers/stuff. Secondary transmission occurred in one primary school and 8 secondary schools. Except for two students and one teacher, the possible source of infection for all index cases was identified as they had all had previous contact with a positive case; the majority of secondary cases did not report any previous close contact with a positive case. The clusters ranged from one to 22 secondary cases.ConclusionsTransmission at school occurred in a non-negligible number of cases, particularly in secondary schools. Prompt testing and isolation of classmates could probably reduce the risk of transmission in school settings.

Objectives To determine the timing of viral clearance (first negative RT-PCR on nasopharyngeal swab) and the probability of viral clearance confirmation (two consecutive negative swabs) in COVID-19 patients and to identify related determinants. Design Population-based prospective cohort study on archive data. Setting Preventive services and hospital care in the Reggio Emilia province, northern Italy. Participants All 1162 subjects testing positive to RT-PCR on nasopharyngeal swabs and diagnosed with COVID-19 in the Reggio Emilia province with at least 30 days of follow-up by 22 April 2020. Main outcome measures Median times from diagnosis and from symptom onset to viral clearance with IQR assessed using the Kaplan-Meier estimator, stratified by included characteristics. The probability of viral clearance confirmation, stratified by time from diagnosis and putative determinants assessed using a multivariate logistic regression model. Results Viral clearance was achieved by 60.6% (704/1162) of patients, with a median time of 30 days from diagnosis (IQR 23-40) and 36 days from symptom onset (IQR 28-45). Of those negative and retested, 78.7% (436/554) had viral clearance confirmation, suggesting one in five false negative tests. The time from symptom onset to viral clearance slightly increased with age, from 35 (IQR 26-44) days under age 50 to 38 (IQR 28-44) in over age 80, and with disease severity, from 33 (IQR 25-41) days in non-hospitalised subjects to 38 (IQR 30-47) days in hospitalised patients. The probability of confirmed viral clearance reached 86.8% after 34 days from symptom onset and increased with time, even when adjusting for age and sex (OR 1.16 95% CI 1.06 to 1.26 per day from diagnosis). Conclusions Postponing follow-up testing of clinically recovered COVID-19 patients could increase the efficiency and performance of testing protocols. Understanding viral shedding duration also has implications for containment measures of paucisymptomatic subjects. ► This is one of the few studies providing populationbased evidence on the duration of viral shedding in SARS-CoV-2-positive patients. ► All patients testing positive for SARS-CoV-2 in the province of Reggio Emilia with a minimum follow-up of 30 days up to 22 April 2020 were included. ► The median time from symptom onset and from diagnosis to viral clearance (ie, first negative RT-PCR assay on nasopharyngeal swab) was assessed and stratified by putative determinants. ► The assessment of time to viral clearance was limited by the testing intervals, which in our study reflect the real-world practice. ► The probability of confirmation of viral clearance (ie, two consecutive negative swabs) was also reported overall and stratified by time from diagnosis and symptom onset.

The aims of this study were to describe the adherence to CDC guidelines for intrapartum antibiotic prophylaxis (IAP) and to identify possible factors influencing noncompliance with guidelines. We conducted a retrospective study in Italy. Our cohort included women in whom antenatal Group B Streptococcus (GBS) screening was not performed, was performed, but results were not available at the time of labor or delivery and women who were positive for GBS colonization. The indications for complete execution of IAP according to revised CDC guidelines was evaluated. It was considered adequate when performed with a recommended antibiotic at least four hours prior to delivery. The cohort included 902 women. Among those who had performed rectal and vaginal swabs (or recto-vaginal swabs), results were available in 86.9% of vaginal swabs and in 87.1% of rectal swabs and GBS was detected in 59.8% of vaginal swabs and in 71% of rectal swabs. 49.2% women had indication for GBS prophylaxis. Among these, 91.1% received an antibiotic during labor. Totally appropriate IAP was performed in 36.3% deliveries, an inappropriate antibiotic was administered in 10.4% women, the remaining 45.3% women received partially appropriate IAP; of these, 15.5% had received antibiotics through an inappropriate route of administration, 18.2% an inappropriate dosage regimen. Overall, 27.5% women received intrapartum ampicillin with inappropriate timing. Multivariate analysis showed that totally appropriate prophylaxis was significantly more likely in women who had no previous live birth, who had vaginal delivery, and a positive result at antenatal GBS screening. Despite satisfactory GBS screening implementation, there is still a substantial gap between optimal and actual IAP. We hypothesize that the complexity of the CDC guidelines may partially explain this shortcoming. Future efforts will include initiatives focused at enabling and reinforcing adherence to evidence-based prevention practices.