SARS-CoV-2 in Human Sewage and River Water from a Remote and Vulnerable Area as a Surveillance Tool in Brazil.

In the present study, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was monitored in environmental samples from rural and vulnerable areas (a presidio, worker accommodation units, and river waters upstream and downstream of a rural community) from Minas Gerais State region, Southern Brazil, in August 2020. The sampling was performed prior to official declaration of the coronavirus disease (COVID-19) cases in those sites. SARS-CoV-2 RNA was detected in the presidio and workers accommodation units (3.0 × 104 virus genome copies (GC)/mL and 4.3 × 104 GC/mL of sewage, respectively). While SARS-CoV-2 was not detected in the river water upstream of the rural community, SARS-CoV-2 RNA was detected in downstream river waters (1.1 × 102 SARS-CoV-2 GC/mL). The results obtained in this study highlight the utility of SARS-CoV-2 monitoring in wastewater and human sewage as a non-invasive early warning tool to support health surveillance in vulnerable and remote areas, particularly in development countries.

The presence of SARS-CoV-2 RNA in human sewage in Santa Catarina, Brazil, November 2019.

Human sewage from Florianopolis (Santa Catarina, Brazil) was analyzed for severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) from October 2019 until March 2020. Twenty five ml of sewage samples were clarified and viruses concentrated using a glycine buffer method coupled with polyethylene glycol precipitation, and viral RNA extracted using a commercial kit. SARS-CoV-2 RNA was detected by RT-qPCR using oligonucleotides targeting N1, S and two RdRp regions. The results of all positive samples were further confirmed by a different RT-qPCR system in an independent laboratory. S and RdRp amplicons were sequenced to confirm identity with SARS-CoV-2. Genome sequencing was performed using two strategies; a sequence-independent single-primer amplification (SISPA) approach, and by direct metagenomics using Illumina's NGS. SARS-CoV-2 RNA was detected on 27th November 2019 (5.49 ± 0.02 log10 SARS-CoV-2 genome copies (GC) L-1), detection being confirmed by an independent laboratory and genome sequencing analysis. The samples in the subsequent three events were positive by all RT-qPCR assays; these positive results were also confirmed by an independent laboratory. The average load was 5.83 ± 0.12 log10 SARS-CoV-2 GC L-1, ranging from 5.49 ± 0.02 log10 GC L-1 (27th November 2019) to 6.68 ± 0.02 log10 GC L-1 (4th March 2020). Our findings demonstrate that SARS-CoV-2 was likely circulating undetected in the community in Brazil since November 2019, earlier than the first reported case in the Americas (21st January 2020).