Environmental Air Sampling of Respiratory Viruses in School Settings: A Scoping Review

Background/Objectives: Schools are recognised sites of exposure to respiratory viruses for students and staff, representing a recognised public health concern. Environmental air sampling has been developed as a non-invasive surveillance approach that can detect circulating respiratory viruses, including those shed by asymptomatic persons, without the need for individual testing. However, the methodological and operational evidence base for this approach within educational settings remains nascent. This scoping review systematically maps the extant literature, characterising targeted respiratory viruses, sampling and analytical methodologies, assessed environmental covariates, and critical knowledge gaps. Methods: Adhering to the PRISMA-ScR guidelines, a systematic search of PubMed, Web of Science, and ScienceDirect was executed without temporal restrictions. Results: Eleven studies met the inclusion criteria. Viral RNA detection frequencies exhibited substantial heterogeneity (0–98.5%), primarily attributable to the study design parameters, single-target assays yielding lower positivity versus broad-spectrum multiplex panels, compounded by the stringency of concurrent infection-control interventions. In the singular investigation reporting comprehensive viral ranking, rhinovirus predominated, followed by respiratory syncytial virus (RSV-A/B), and influenza A/B. SARS-CoV-2 detection was profoundly influenced by the pandemic phase dynamics. Critically, all positive detections signified nucleic acid presence, with zero studies confirming viable virions via infectivity assays, representing a fundamental interpretive limitation. Conclusions: Airborne respiratory viral RNA from infected school occupants is unequivocally detectable, positioning environmental sampling as a promising adjunct to clinical surveillance for syndromic characterisation. Nevertheless, translating this approach into a robust, real-time operational infection-control instrument necessitates rigorous methodological harmonisation, alongside comprehensive assessments of viral infectivity, economic viability, and pragmatic feasibility to bridge prevailing translational gaps. Beyond mapping the primary studies, this review additionally benchmarks school-based sampling against practice in hospitals, universities, and other congregate settings, evaluates surface sampling as a complementary environmental modality, and analyses the dilution-limited regime that governs airborne viral detection in ventilated classrooms, which defines the performance envelope that next-generation high-flow, low-loss samplers must meet.