Hospital Wastewater Surveillance of SARS-CoV-2 RNA: Association With COVID-19 Cases and Insights into Environmental Persistence

Introduction: Analyzing municipal wastewater for the presence of SARS-CoV-2 RNA serves as a cost-effective and timely tool for epidemiological surveillance to mitigate virus-related health risks. Therefore, this study assessed the presence of SARS-CoV-2 RNA in untreated hospital wastewater and its correlation with COVID-19 case numbers over six months at Shahidzadeh Hospital in southwest Iran. Materials and Methods: In this analytical investigation, a total of 24 grab samples of untreated hospital wastewater were systematically collected over six months, spanning from September 2020 to February 2021. Each sample was subsequently processed and analyzed using a reverse transcription quantitative polymerase chain reaction (RT-qPCR) approach, with specific amplification targeting both the RNA-dependent RNA polymerase (RdRp) gene and the nucleocapsid (N) gene of SARS-CoV-2. Results: All 24 wastewater samples tested positive for SARS-CoV-2 RNA. Concentrations ranged between 130 to 490 gene copies/100 mL, with mean values increasing from 247 (September) to 425 (February). RNA levels were strongly correlated with hospitalized COVID-19 cases (Spearman’s p < 0.05, R² = 0.87). Conclusion: These findings highlight the value of hospital wastewater surveillance as a cost-effective epidemiological tool, particularly in settings with limited diagnostic capacity. Future research should investigate viral viability and optimize disinfection strategies to reduce potential environmental risk.