Masking of Health Care Workers Cuts SARS-CoV-2 Positivity

FRIDAY, July 17, 2020 (HealthDay News) — Universal masking of health care workers (HCWs) is associated with a reduction in the rate of SARS-CoV-2 positivity, according to a study published online July 14 in the Journal of the American Medical Association.

Xiaowen Wang, M.D., from Brigham and Women’s Hospital in Boston, Massachusetts, and colleagues examined the correlation of hospital masking policies with the SARS-CoV-2 infection rate among HCWs. Three phases were identified during the study period: a preintervention period before implementation of universal masking of HCWs; a transition period until implementation of universal masking of patients; and an intervention period.

The researchers found that 12.9 percent of 9,850 tested HCWs had positive results for SARS-CoV-2. The SARS-CoV-2 positivity rate increased exponentially from 0 to 21.32 percent during the preintervention period, with a weighted mean increase of 1.16 percent per day and 3.6 days for case doubling time. The positivity rate decreased linearly during the intervention period, from 14.65 to 11.46 percent, with a weighted mean decline of 0.49 percent per day; compared with the preintervention period, a net slope change of 1.65 percent more decline per day was observed.

“The report by Wang et al provides practical, timely, and compelling evidence that community-wide face covering is another means to help control the national COVID-19 crisis,” write the authors of an accompanying editorial. “Community-level protection afforded by use of cloth face coverings can reduce the number of new infections and facilitate cautious easing of more societally disruptive community interventions.”

Several authors disclosed ties to the pharmaceutical industry.

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