Study: COVID-19 first detected in Spain

According to foreign media, a study led by the University of Barcelona (UB) has detected the presence of SARS-CoV-2 in wastewater samples from Barcelona on March 12, 2019.

The research results, published on the medical research website medRxiv, indicate that the virus was present long before any reported case of Covid-19, the university reports.

The research is part of a project on the coronavirus that aims to detect it in wastewater to facilitate the adoption of new measures. The results come from the analysis of frozen samples, showing the virus present in the water on January 15 this year but also in an example from March 2019, although at "very low" levels.

Although Covid-19 is a respiratory disease, it has been shown that feces, which subsequently reach wastewater, have large amounts of the coronavirus genome.

Since April 13, researchers have been analyzing samples obtained at two large wastewater treatment plants in Barcelona. The professor of the Faculty of Biology at the UB and coordinator of the work, Albert Bosch, explained that the genome levels of SARS-CoV-2 coincided "clearly" with the evolution of confirmed Covid-19 cases in the population.

Subsequently, the researchers analyzed frozen samples from the months before the confirmation of cases among citizens. These analyses revealed the growing appearance of SARS-CoV-2 genomes between early January and early March this year, advancing the chronology of the arrival of the coronavirus in Spain.

The presence of viruses was already detected on January 15, 41 days before the first case declaration on February 25.

Bosch, who is also president of the Spanish Society of Virology, stated that in the specific case of Barcelona, "having detected the spread of SARS-CoV-2 a month in advance would have allowed a better response to the pandemic."

According to him, Barcelona receives many visitors and considered it "more than likely" that a similar situation has occurred in other parts of the world. "Since most cases of Covid-19 show flu-like symptoms, the former should have been masked as undiagnosed flu cases," he concluded.