Fig. 4.

Summary of routine SARS-CoV-2 monitoring data for (A) Facility 1 from early March to late May and (B) Facility 2 from early April to late May. The symbols represent SARS-CoV-2 or PMMoV concentrations (all adjusted for equivalent sample volume and recovery). For SARS-CoV-2, open symbols indicate the sample was >LoD but < LoQ, gray symbols indicate the sample was >LoQ with detections in only one of two qPCR replicates, and black symbols indicate the sample was >LoQ with detections in both qPCR replicates. Gray columns indicate the number of positive reactions out of eight (four assays with duplicate qPCR reactions).