ABSTRACT
Wastewater monitoring of SARS-CoV-2 allows for early detection and monitoring of COVID-19 burden in communities and can track specific variants of concern. Targeted assays enabled relative proportions of SARS-CoV-2 Omicron and Delta variants to be determined across 30 municipalities covering >75% of the province of Alberta (pop. 4.5M) in Canada, from November 2021 to January 2022. Larger cities like Calgary and Edmonton exhibited a more rapid emergence of Omicron relative to smaller and more remote municipalities. Notable exceptions were Banff, a small international resort town, and Fort McMurray, a more remote northern city with a large fly-in worker population. The integrated wastewater signal revealed that the Omicron variant represented close to 100% of SARS-CoV-2 burden prior to the observed increase in newly diagnosed clinical cases throughout Alberta, which peaked two weeks later. These findings demonstrate that wastewater monitoring offers early and reliable population-level results for establishing the extent and spread of emerging pathogens including SARS-CoV-2 variants.
ABSTRACT
Nasopharyngeal (NP), nasal and throat swabs are the most practical specimen sources to test for upper respiratory pathogens. We compared the sensitivity of NP, nasal and throat swabs to detect SARS-CoV-2 in community patients. Using detection at any site as the standard, the sensitivities were 90%, 80% and 87% for NP, nasal and throat respectively (n=30 positive at any site). Throat swabs are likely a suitable alternative to NP swabs for the detection of COVID-19 infections.
