Milan: In an innovative approach to public health, Italy is preparing to use its nationwide sewage network to detect early signs of COVID-19 resurgences and emerging variants, officials said. The initiative aims to provide authorities with a preemptive tool for pandemic monitoring, potentially alerting them to rising cases before clinical testing or hospital admissions reveal trends.

The program, led by the National Health Institute (Istituto Superiore di Sanità, ISS), is slated to launch within two to three months. It will operate across 166 sampling points in the country, with 60 laboratories analyzing wastewater. In cities with populations exceeding 150,000, samples will be collected twice weekly, while towns of more than 50,000 residents will see weekly testing.

Giuseppina La Rosa, co-head of wastewater monitoring at ISS, explained that the method offers a “photograph of the whole population,” unlike traditional surveillance which only covers individuals who undergo testing. Environmental sampling may also detect less common variants that could escape detection through standard swabbing.

Experts say that wastewater monitoring has been utilized in countries like Canada and the Netherlands since early in the pandemic, providing critical epidemiological insights. However, creating predictive models from sewage data involves challenges, such as accounting for rainfall or other factors that can dilute or alter viral content, noted Luca Lucentini, ISS Director of Water Quality.

Beyond early detection, the project will allow Italian authorities to review archived samples, potentially revealing when variants like Omicron first appeared in the country. In fact, earlier ISS studies identified traces of SARS-CoV-2 in Milan and Turin wastewater from December 2019, indicating that the virus circulated in Italy earlier than initially reported.

With rising global concern over infectious variants and the risk of testing shortages, Italy’s sewage surveillance system represents a strategic, proactive step. Officials hope it will support timely health policy decisions, including the possible implementation of measures to curb transmission and protect public health without unnecessary delays.