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Incidence of infection among school staff in Italy https://alessandroferrettiblog.wordpress.com/2020/12/07/cade-il-velo-sui-contagi-nelle-scuole-piemontesi-il-personale-da-due-a-quattro-volte-piu-esposto-della-media-la-situazione-nelle-materne-e-drammatica-solo-le-superiori-si-salvano-grazie-alla-dad/
Proportion of infections among school staff compared to the general population. Shift of 50% of high-school students to online learning on Oct 26 reduced staff infection rates to below rest of population.
Starting Nov 2nd, distance learning was introduced to 100% of high-school students, and in the following week (Nov. 9-15) the percentage of infections among the staff fell below the general population rates.
Infection incidence among middle school staff (gray) exceeded that of the population starting Oct 12. The increase is much more dramatic in the week of Nov 2 the infection incidence among staff was triple that of the population.
Restrictive measures were introduced on Nov 2 (distance learning for mid-grades 2-3), and incidence starts to drop the following week, but is still 230% higher than the general population.
Infection prevalence is 7.3% among staff compared with 3.1% for the general population.
Infection prevalence is 7.3% among staff compared with 3.1% for the general population.
For primary school (orange), compulsory mask was introduced for all kids over 6y on Nov 2nd, but the decline in infection was only brief. By Nov 23 the incidence among staff compared to that on the population reached 285%, of general population rates.
Infections among nursery school staff was the highest. By Nov 2nd, the infections were 360% higher than rest of population. No restrictive measures meant the incidence continued to increase and by Nov 23 it was almost 400% higher than among general population.
Over the period a total of 10.8% of the staff of nursery schools were infected compared to 3.1% of the general population.
These incidences are likely to be underestimated because positivity rates are extremely high in the region, reaching 51% among school staff, and 35% among the general population on Nov 9.
The data was obtained by the regional councilor, Francesca Frediani, who requested and obtained the weekly infection data for school staff and students from Sept 18 onwards, by type of school and sub-region (province). All data here: https://docs.google.com/file/d/1aMr_E_CD7L3TPLtfrwYMGmmjvB7SwdeV/edit?usp=docslist_api&filetype=msexcel
As @Ale_x_Ferretti points out, varying infection rates among staff teaching different school grades strongly suggests infection is happening in the classroom and not while commuting or in other school areas. There increase in risk is associated with face-to-face teaching.
