Detecção e quantificação de fragmentos de RNA viral do SARS-CoV-2 no esgoto da Universidade Federal de Alfenas do Campus de Poços de Caldas

Abstract

COVID-19 has resulted in significant economic impacts and a tragic number of deaths. During the pandemic, Brazil experienced limited clinical testing, which contributed to the exacerbation of the disease. Wastewater-based epidemiology (WBE) is a method that enables the detection of fragmented SARS-CoV-2 genetic material present in wastewater, allowing for large-scale monitoring of COVID-19. This study aimed to detect and quantify RNA fragments of SARSCoV-2, the causative agent of COVID-19, in the sewage of the Federal University of Alfenas – Poços de Caldas campus and to investigate a relationship between the concentration of viral RNA and the physicochemical characteristics of the wastewater. The raw sewage was collected from the suction well of the university's sewage pumping station. Along with molecular biology analyses, sewage was characterized using physical-chemical parameters, including Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), pH, series of solids, sulfate and phosphorus. These aimed to characterize the sewage to avoid distortion of the samples, due to dilution and other interfering factors. Viral RNA was found in all weeks analyzed, with an average concentration of 3.74x105 copies RNA/L. The detection of genetic material indicates the presence of students or employees positive for the disease on campus. The Spearman correlation analysis showed high correlations between the sewage parameters, showing that wastewater in this study had similar characteristics to the sanitary sewage found in cities, ensuring that the samples did not suffer significant impacts from dilution among other possible external factors. With regard to the correlation with the concentration of viral RNA, settleable solids showed a strong correlation, greater than 0.591.