SARS-CoV-2 contamination potential in environmental and wastewaters in the Algarve region, Southern Portugal

The Ria Formosa, Southern Portugal (Algarve) is a mesotidal lagoon with restricted exchange Atlantic Ocean. Due to arid Mediterranean climate and absence of large freshwater inputs, the remains hypersaline relative adjacent ocean (≥37 psu). Generally, fecal coliforms land-derived bacteria do not survive long in seawater due UV, osmotic shock, oligotrophy competition marine bacteria. However, survival human pathogenic viruses natural waters relatively unknown. In view 2020–2021 SARS-CoV-2 pandemic, this preliminary study aimed estimate potential contamination by wastewater persistence environment. Five sampling campaigns (45 total samples) were completed 2020 2021 at three stations lagoon, as well inflow outflow from treatment plants (WWTPs). Despite high stations, could be detected surface using improved methodology. Untreated wastewaters positive Faro-Aeroporto 21/10/2020, 14/12/2020, 08/03/2021; Vilamoura 14/12/2020; Olhão 14/12/2020. All treated negative, environmental samples. Highest viral titers observed WWTP on 8 March (1.35 x 10 5 genomic copies L −1 ) coinciding peak cumulative cases Algarve (2.03 4 ), yet was raw then. Thus, seemed non-existent Formosa during pandemic surges Algarve. predicted change its impact microbial populations challenge addressed both health tourist authorities.