What is the evidence about and international and Canadian experiences with asymptomatic screening to identify COVID-19 cases and to prevent transmission?

We identified several documents that we deemed to provide highly relevant evidence to the question, which includes one systematic review, one rapid review, and six guidelines from four groups –Australian National COVID-19 Clinical Evidence Taskforce, Chinese Centre for Disease Control (CDC), U.S. CDC, and World Health Organization – that were developed using some type of evidence synthesis and/or expert opinion. The only highly relevant documents we identified in relation to long-term care settings were two primary studies.