RESUMEN
BackgroundWastewater surveillance has been proposed as an epidemiological tool to define the prevalence and evolution of the SARS-CoV-2 epidemics. However, most implemented SARS-CoV-2 wastewater surveillance projects were relying on qPCR measurement of virus titers and did not address the mutational spectrum of SARS-CoV-2 circulating in the population. MethodsWe have implemented a nanopore RNA sequencing monitoring system in the city of Nice (France, 550,000 inhabitants). Between October 2020 and March 2021, we monthly analyzed the SARS-CoV-2 variants in 113 wastewater samples collected in the main wastewater treatment plant and 20 neighborhoods. FindingsWe initially detected the lineages predominant in Europe at the end of 2020 (B.1.160, B.1.177, B.1.367, B.1.474, and B.1.221). In January, a localized emergence of a variant (Spike:A522S) of the B.1.1.7 lineage occurred in one neighborhood. It rapidly spread and became dominant all over the city. Other variants of concern (B.1.351, P.1) were also detected in some neighborhoods, but at low frequency. Comparison with individual clinical samples collected during the same week showed that wastewater sequencing correctly identified the same lineages as those found in COVID-19 patients. InterpretationWastewater sequencing allowed to document the diversity of SARS-CoV-2 sequences within the different neighborhoods of the city of Nice. Our results illustrate how sequencing of sewage samples can be used to track pathogen sequence diversity in the current pandemics and in future infectious disease outbreaks.
RESUMEN
ObjectivesThe variant 20I/501Y.V1, associated to a higher risk of transmissibility, emerged in Nice city (South East of France, French Riviera) during January 2021. The pandemic has resumed late December 2020 in this aera. A high incidence rate together with a fast turn-over of the main circulating variants, provided us the opportunity to analyze modifications in clinical profile and outcome traits. MethodsObservational study in the University hospital of Nice from December 2020 to February 2021. We analyzed data of sequencing of SARS-CoV-2 from the sewage collector and PCR screening from all positive samples at the hospital. Then, we described the characteristics of all COVID-19 patients admitted in the emergency department (ED) (n=1247) and those hospitalized in the infectious diseases ward or ICU (n=232). Demographic data, clinical signs and severity were recorded by the NEWS-2, SAPS-2 and SOFA scores were recorded and analyzed. Resultsthe UK-variant was absent in the area in December, then increasingly spread in January representing 59% of the PCR screening performed mid-February. The rate of patients over 65 years admitted to the ED decreased from 63% to 50% (p=0.001). The mean age of hospitalized patients in the infectious diseases ward decreased from 70.7 to 59.2 (p<0.001) while the proportion of patients without comorbidity increased from 16% to 42% (p=0.007). Neither the NEWS-2 score nor the main signs of clinical severity have changed over time. ConclusionSpread of the UK-variant in the South East of France affects younger and healthier patients.