Detection of SARS-CoV-2 in drainage systems from tourist buses and bus station in Mexico

Any means of public transportation (aircraft, ships, and buses) may carry potentially covid19 positive individuals thus, wastewater-based epidemiology (WBE) should be implemented to avoid further spread. The present study focused on tracing the presence of SARS-CoV-2 in wastewater from holding tanks of national and international route buses, as well as the drainage system at the bus station. Testing was performed by the RT-PCR protocol established by the United States Center for Disease Control and Prevention (CDC). SARS-CoV-2 was detected in 8.88% of the wastewater samples from buses and drainage systems (4 of 45). Positives samples were sequenced, and Delta and Omicron were among the variants most prevalent. Our results show that WBE provides a reliable and sensitive tool for spotting the possible presence of COVID-19-positive individuals arriving by bus to a city. Also, the WBE coupled with Whole Genome Sequencing (WGS) may serve as an early warning to trace and display preventative measures upon the introduction of variants of concern.