SARS-CoV-2 in river water: Implications in low sanitation countries

Area of Science:

• Environmental Virology
• Public Health
• Water Quality Monitoring

Background:

• Studies confirm SARS-CoV-2 shedding in feces of infected individuals.
• High viral loads are observed in sewage systems during COVID-19 outbreaks.
• Many cities globally discharge untreated wastewater into natural water bodies.

Purpose of the Study:

• To assess the presence and quantify SARS-CoV-2 in urban streams within Quito, Ecuador.
• To evaluate viral contamination in a low sanitation context.
• To use Human Adenovirus as an indicator of human viral contamination.

Main Methods:

• Sampling of three urban river locations in Quito during a COVID-19 surge.
• Water quality parameter assessment.
• Viral concentration using skimmed milk flocculation.
• Quantitative detection of SARS-CoV-2 (N1 and N2 targets) via RT-qPCR.
• Quantification of Human Adenovirus as a viral indicator.

Main Results:

• SARS-CoV-2 detected in all river samples for both N1 and N2 target regions.
• Quantified viral loads ranged from 2.91E+05 to 3.19E+06 GC/L for N1.
• Quantified viral loads ranged from 2.07E+05 to 2.22E+06 GC/L for N2.

Conclusions:

• Significant SARS-CoV-2 contamination found in urban streams in a low sanitation setting.
• The high viral loads have potential implications for public health and ecological safety.
• Further assessment of health and ecological impacts is warranted.