Viral load in Thessaloniki wastewater shoots up, painting bleak picture for days ahead

Viral load in Thessaloniki wastewater shoots up, painting bleak picture for days ahead

The concentration of the SARS-CoV-2 virus detected in raw sewage at Thessaloniki’s wastewater treatment plant shot up 70% in the week between February 8 and 14, a team of researchers from the northern port city’s Aristotle University warned on Tuesday.

The sudden spike in the viral load comes after several weeks of a slow but steady increase, the head of the team, Nikos Papaioannou, who is also rector of the Aristotle University, told the state-run Athens-Macedonian News Agency (ANA-MPA) on Tuesday.

“Our most recent measurements have shown a steep rise in the epidemiological curve,” he said.

“Of course, if we compare the latest weekly average to that of January 18-21, to the period after Christmas when we were at our lowest level, the viral load is up by 345% today. Compared with the autumn wave, we are now at level similar to late October, just before the start of November’s spike in transmission,” the professor added.

Papaioannou said his team, which is working in cooperation with the Thessaloniki Water and Sewerage Company, has stepped up analyses of the city’s wastewater, taking daily samples instead of weekly ones in a bid to help prevent the kind of explosion in transmission seen last November.

“The rise we have been seeing since the start of the month in the wastewater, will become apparent in the next few weeks at hospitals,” warned Symeon Metallidis, a professor of epidemiology at the Aristotle who also works at Thessaloniki’s AHEAP hospital and sits on the committee of experts advising the government on its handling of the pandemic.

“Wastewater gives us a timely diagnosis, a picture of what we will see later clinically. The methodology is very well targeted and reliable,” he added.

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