COVID-19 is currently the most critical disease in the world. Thus, several tools have been used in the last two years to contain the spread of SARS-CoV-2. In this perspective, Wastewater-Based Epidemiology (WBE) provides valuable data by including symptomatic, pre-symptomatic, and asymptomatic individuals and anticipating clinical cases. For 37 weeks, the SARS-CoV-2 viral load was monitored in sanitary sewage samples from Goiânia-Brazil. Through pre-concentration, extraction, and purification of viral RNA, followed by RT-qPCR, it was detected in 83.78% (31/37) of the weeks the presence of fragments of the genetic material SARS-CoV-2 with viral loads ranging from 105 to 108 genome copies L-1. The viral load in the wastewater samples was related to the clinical data of the municipality, demonstrating its ability to promote an Early Warning System (EWS). In early 2022, it was possible to predict the increase in clinical cases 3 weeks in advance and issue an alert note to the health authorities. Prevalence estimates ranged from 0.003 to 0.5% and showed good agreement with observed values. Thus, monitoring effluents become another essential tool that can help combat the pandemic’s advance, especially in countries with scarce resources.

RESUMO A vigilância da qualidade dos esgotos sanitários pode representar uma ferramenta complementar para monitoramento de doenças infecciosas e prevenção de surtos epidêmicos, especialmente quando a capacidade para testes clínicos é limitada. Dessa maneira, o presente estudo descreve o detalhamento técnico de um método de baixo custo para a concentração e extração de ácidos nucleicos de amostras de esgoto sanitário como etapa prévia para a detecção de vírus e outros agentes patogênicos. Para validar a metodologia proposta, após as etapas de concentração e extração, analisaram-se a presença do ácido ribonucleico do SARS-CoV-2 (COVID-19) nas amostras, por meio de reação em cadeia da polimerase em tempo real. O ácido ribonucleico do vírus foi detectado em 80% das amostras de esgoto sanitário analisadas, comprovando o êxito do procedimento metodológico adotado. A detecção precoce de um patógeno associado ao trabalho de equipes multidisciplinares possibilita a prática da vigilância epidemiológica, que auxilia na tomada de decisões na Saúde Única — união indissociável entre a saúde animal, humana e ambiental.

ABSTRACT Sewage quality surveillance can represent a complementary tool for monitoring infectious diseases and preventing epidemic outbreaks, especially when the capacity for clinical testing is limited. Thus, the present study describes the technical details of a low-cost method for concentrating and extracting nucleic acids from sewage samples, as a preliminary step for the detection of viruses and other pathogens. To validate the proposed methodology, after the concentration and extraction steps, the presence of the SARS coronavirus-2 (COVID-19) in the samples was analyzed using real-time polymerase chain reaction. The virus’ ribonucleic acid was detected in 80% of the sewage samples analyzed, proving the success of the methodological procedure adopted. The early detection of a pathogen associated with the work of multidisciplinary teams allows the practice of epidemiological surveillance, which assists in making decisions about One Health — an inseparable union between animal, human, and environmental health.