Effectiveness of filtering or decontaminating air to reduce or prevent respiratory infections: A systematic review

Abstract

AbstractBACKGROUNDInstallation of technologies to remove or deactivate respiratory pathogens from indoor air is a plausible non-pharmaceutical disease control strategy.METHODSWe undertook a systematic review of observational and experimental studies, published 1970-2022, to synthesise evidence about the effectiveness of suitable indoor air treatment technologies to prevent respiratory or gastrointestinal infections. We searched for data about infection and symptom outcomes for persons who spent minimum 20 hours/week in shared indoor spaces subjected to air treatment strategies hypothesised to change risk of respiratory or gastrointestinal infections or symptoms.RESULTSPooled data suggested no net benefits for symptom severity or symptom presence, in absence of confirmed infection. There was weak evidence that air treatment technologies tended to reduce confirmed infections, but these data evinced strong publication bias.CONCLUSIONAlthough environmental and surface samples are reduced after air treatment by several air treatment strategies, especially germicidal lights and high efficiency particulate air filtration, robust evidence has yet to emerge to confirm that these technologies are effective in real world settings. Data from several relevant randomised trials have yet to report and will be welcome to the evidence base.