Effectiveness of Physical Distancing: Staying 6 Feet Over to Put Respiratory Viruses 6 Feet Under.

Freeman, Catherine M; Rank, Matthew A; Bolster LaSalle, Catherine M; Grys, Thomas E; Lewis, John C

Community transmission of severe acute respiratory illness Coronavirus-2 (SARS-CoV-2) in Arizona was noted in March 2020. It was our hypothesis that the associated implementation of physical distancing and masking led to a decline in circulation and detection of common respiratory viruses. Nasopharyngeal swabs processed with the Biofire, Film Array respiratory panel at Mayo Clinic Arizona were reviewed from January 1, 2017, to July 31, 2020. A total of 13,324 nasopharyngeal swabs were analyzed. Between April and July 2017- 2019 (Period A) a mean of 262 tests were performed monthly, falling to 128 for the corresponding months of 2020 (Period B). A reduction in the monthly mean number of positive tests (Period A 71.5; Period B 2.8) and mean positivity rate (Period A 25.04%; Period B 2.07%) was observed. Rhinovirus/enterovirus was the most prevalent virus, with a monthly mean of 21.6 cases (30.2% of positives) for Period A and 2 cases (72.7% of positives) for Period B. Positivity for a second virus occurred in a mean of 2.1 positive tests (3.3%) in Period A but was absent in Period B. Implementation of distancing and masking coincides with a marked reduction in respiratory virus detection and likely circulation. Data from the fall/winter of 2020 will help clarify the potential role for distancing and masking as a mitigation strategy, not only for SARS-CoV-2 but also in the seasonal battle against common respiratory viruses.