An Epidemiological Assessment of SARS-CoV-2 in the Sewage System of a Higher Education Institution

TL;DR

This study monitored SARS-CoV-2 in sewage at a university campus to assess its potential as a low-cost tool for tracking outbreaks.

Contribution

The study demonstrates sewage monitoring as a cost-effective alert system for SARS-CoV-2 in post-pandemic settings.

Findings

SARS-CoV-2 RNA was detected in two out of 15 sewage samples collected over 66 days.

The pH of the sewage samples ranged from 6.35 to 8.17, and the samples were cloudy with impurities.

An increase in reported cases in the state coincided with the collection period of the positive samples.

Abstract

Background: The World Health Organization declared the end of the COVID-19 pandemic in May 2023, three years after the adoption of global emergency measures. Monitoring of SARS-CoV-2 in sewage underscores its importance due to its effectiveness and cost-effectiveness, highlighting the need to prioritize research on water resources and sanitation.

Objectives: The aim of this study was to conduct an epidemiological assessment of SARS-CoV-2 in the sewage system of a higher education institution located in Vitória Espírito Santo State, Maruípe campus.

Methods: Over a period of 66 days, from February 6 to April 12, 2023, 15 samples were collected. Each sample consisted of 1 L, collected in 1 hour, with 250 mL collected every 15 minutes. The samples were characterized by assessing their appearance, and pH was measured using a Horiba U-50 multiparameter probe. The extracted RNA was subjected to RT-qPCR using the Allplex™ 2019-nCovAssay Seegene kit.

Results: The samples exhibited a cloudy appearance with impurities, and the pH ranged from 6.35 to 8.17. Among the evaluated samples, SARS-CoV-2 RNA was detected in two, and, by comparing this with the epidemiological bulletin issued by the State Health Department, an increase in cases in the state was observed during the collection period of these samples.

Conclusions: Sewage monitoring proved to be an important tool in this post-pandemic period, serving as an alert and prevention mechanism for the population in relation to new outbreaks. Furthermore, it represents a low-cost mapping strategy and extensive testing of a population, aligning with the studies presented at the beginning of the pandemic. We recommend specific adjustments considering distinct populations.

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