(13.06.2020)

This SARS-CoV-2 early detection in sewage supports the idea that COVID-19 cases may have been present in the population beforethe first imported case was reported. COVID-19 carriers may have been misclassified as influenza diagnoses in primary care, boosting community transmission before public health measures were taken(11).

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Most COVID-19 cases show mild influenza-like symptoms (14)and it has been suggested that some uncharacterized influenza cases may have masked COVID-19 cases in the 2019-2020 season (11).