Upper-room germicidal ultraviolet light reduced respiratory-related absenteeism among pre-school students: an analysis of newly discovered historical data

ObjectivesTo assess the effect of upper-room germicidal ultraviolet light systems (GUV) on child absenteeism from a preschool. MethodsI fit a generalized linear model for interventional time series to a newly-discovered historical dataset of attendance records from a preschool from 1941 to 1949, where GUV was installed in December 1945. ResultsIn all but peak summer months, the presence of GUV was associated with a sizable reduction in child absenteeism due to respiratory illnesses of any cause. Odds ratios for the effect ranged from 0.49 to 0.77, depending on season. In all but high summer, model-predicted absenteeism rates with GUV were a third to a half what they were without it. ConclusionsInstallation of upper-room germicidal light in a preschool in December 1945 was associated with a signficant and operationally meaningful reduction in absenteeism due to respiratory illness of any cause. While todays overall epidemiological environment may be different from that of the 1940s, COVID-19 has shown us that the human species remains vulnerable to pandemics of novel respiratory pathogens, to say nothing of annual influenza outbreaks. Thus air disinfection in congregate indoor settings remains a critical issue. Wider use of upper-room germicidal UV systems in schools and preschools may be worthwhile to reduce absenteeism due to illness, and the educational, social, and economic consequences that ensue.