The incidence and geographical spread of SARS-CoV-2 in Rio de Janeiro, Brazil based on RT-PCR test results.

INTRODUCTION: Rio de Janeiro has hardly experienced coronavirus disease. METHODS: Here, 87,442 reverse transcription polymerase chain reaction (RT-PCR) test results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were reported among Rio de Janeiro residents (March to September 2020). RESULTS: Overall, RT-PCR positivity of 44.6% decreased over time towards 20%. Positivity was greater among males (OR=1.22; 95%CI:1.19-1.26); Black (OR=1.10; 95%CI:1.02-1.19), Brown (OR=1.16; 95%CI:1.10-1.22), and indigenous people (OR=2.11; 95%CI:0.88-5.03) compared to Whites and increased with age; with epidemic spread from the capital to inland regions. CONCLUSIONS: SARS-CoV-2 keeps spreading in Rio de Janeiro, and reopening of activities may fuel the epidemic.

Genomic surveillance of SARS-CoV-2 tracks early interstate transmission of P.1 lineage and diversification within P.2 clade in Brazil.

The sharp increase of COVID-19 cases in late 2020 has made Brazil the new epicenter of the ongoing SARS-CoV-2 pandemic. The novel viral lineages P.1 (Variant of Concern Gamma) and P.2, respectively identified in the Brazilian states of Amazonas and Rio de Janeiro, have been associated with potentially higher transmission rates and antibody neutralization escape. In this study, we performed the whole-genome sequencing of 185 samples isolated from three out of the five Brazilian regions, including Amazonas (North region), Rio Grande do Norte, Paraíba and Bahia (Northeast region), and Rio de Janeiro (Southeast region) in order to monitor the spread of SARS-CoV-2 lineages in Brazil in the first months of 2021. Here, we showed a widespread dispersal of P.1 and P.2 across Brazilian regions and, except for Amazonas, P.2 was the predominant lineage identified in the sampled states. We estimated the origin of P.2 lineage to have happened in February, 2020 and identified that it has differentiated into new clades. Interstate transmission of P.2 was detected since March, but reached its peak in December, 2020 and January, 2021. Transmission of P.1 was also high in December and its origin was inferred to have happened in August 2020. We also confirmed the presence of lineage P.7, recently described in the southernmost region of Brazil, to have spread across the Northeastern states. P.1, P.2 and P.7 are descended from the ancient B.1.1.28 strain, which co-dominated the first phase of the pandemic in Brazil with the B.1.1.33 strain. We also identified the occurrence of a new lineage descending from B.1.1.33 that convergently carries the E484K mutation, N.9. Indeed, the recurrent report of many novel SARS-CoV-2 genetic variants in Brazil could be due to the absence of effective control measures resulting in high SARS-CoV2 transmission rates. Altogether, our findings provided a landscape of the critical state of SARS-CoV-2 across Brazil and confirm the need to sustain continuous sequencing of the SARS-CoV-2 isolates worldwide in order to identify novel variants of interest and monitor for vaccine effectiveness.

The incidence and geographical spread of SARS-CoV-2 in Rio de Janeiro, Brazil based on RT-PCR test results.

INTRODUCTION: Rio de Janeiro has hardly experienced coronavirus disease. METHODS: Here, 87,442 reverse transcription polymerase chain reaction (RT-PCR) test results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were reported among Rio de Janeiro residents (March to September 2020). RESULTS: Overall, RT-PCR positivity of 44.6% decreased over time towards 20%. Positivity was greater among males (OR=1.22; 95%CI:1.19-1.26); Black (OR=1.10; 95%CI:1.02-1.19), Brown (OR=1.16; 95%CI:1.10-1.22), and indigenous people (OR=2.11; 95%CI:0.88-5.03) compared to Whites and increased with age; with epidemic spread from the capital to inland regions. CONCLUSIONS: SARS-CoV-2 keeps spreading in Rio de Janeiro, and reopening of activities may fuel the epidemic.