SARS-CoV-2 has recently been detected in feces, which indicates that wastewater may be used to monitor viral prevalence in the community. Here, we use RT-qPCR to monitor wastewater for SARS-CoV-2 RNA over a 74-day time course. We show that changes in SARS-CoV-2 RNA concentrations follow symptom onset gathered by retrospective interview of patients but precedes clinical test results. In addition, we determine a nearly complete (98.5%) SARS-CoV-2 genome sequence from wastewater and use phylogenetic analysis to infer viral ancestry. Collectively, this work demonstrates how wastewater can be used as a proxy to monitor viral prevalence in the community and how genome sequencing can be used for genotyping viral strains circulating in a community.

SARS-CoV-2 has recently been detected in feces, which indicates that wastewater may be used to monitor viral prevalence in the community. Here we use RT-qPCR to monitor wastewater for SARS-CoV-2 RNA over a 52-day time course. We show that changes in SARS-CoV-2 RNA concentrations correlate with local COVID-19 epidemiological data (R2=0.9), though detection in wastewater trails symptom onset dates by 5-8 days. We determine a near-complete (98.5%) SARS-CoV-2 genome sequence from the wastewater and use phylogenic analysis to infer viral ancestry. Collectively, this work demonstrates how wastewater can be used as a proxy to monitor viral prevalence in the community and how genome sequencing can be used for high-resolution genotyping of the predominant strains circulating in a community.

SARS-CoV-2 genomic surveillance identifies naturally occurring truncation of ORF7a that limits immune suppression Graphical abstract Highlights d ORF7a mutations are found in SARS-CoV-2 genomes isolated from around the globe d The ORF7aD115 isolate displays a replication defect d An ORF7a mutation limits viral suppression of the interferon response

Intrinsic signal amplification by type III CRISPR-Cas systems provides a sequence-specific SARS-CoV-2 diagnostic Graphical abstract Highlights d Sequence-specific recognition of RNA by CRISPR Csm complex activates Cas10 d Cas10 polymerizes ATP to make cyclic oligonucleotides, pyrophosphates, and protons d Cas10's rapidly amplified products are detectable in 1-30 min d RT-LAMP can be coupled to T7-Csm to rapidly and sensitively detect SARS-CoV-2 RNA

To combat viral pandemics, there is an urgent need for inexpensive new technologies that enable fast, reliable, and scalable detection of viruses. Here we repurposed the type III CRISPR-Cas system for sensitive and sequence specific detection of SARS-CoV-2 in an assay that can be performed in one hour or less. RNA recognition by type III systems triggers Cas10-mediated polymerase activity, which simultaneously generates pyrophosphates, protons and cyclic oligonucleotides. We show that amplified products of the Cas10-polymerase are detectable using colorimetric or fluorometric readouts.