Comparing SARS-CoV-2 air and surface contamination in the first vs. second waves

Way back during the first wave of COVID-19 (April 2020), we got our swabs out and sampled surfaces and air across a range of settings in the hospital. This cross-sectional study identified SARS-CoV-2 RNA on a rather startling 52% of surfaces and 45% of air samples collected from across the hospital and some public areas. During the second wave (January 2021), we undertook a similar exercise, and identified a vastly different level of contamination with SARS-CoV-2 RNA: 5% of surfaces and 4% of air samples. What had changed between April 2020 and January 2021 to explain this difference? A whole host of things, and we don’t know for sure – but I suspect that improved testing availability and the introduction of masks for staff and patients were the most important factors.

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